PREP 2018 Flashcards
What are the 4 primary risk factors for maternal cardiac complications in pregnancy according to CARPREG?
- NYHA class II symptoms or cyanosis (SpO2 <90%)
- Prior cardiac event or arrhythmia
- Left heart obstruction (peak gradient 30mmHg)
- Systemic ventricular dysfunction
Having any 1 of the 4 CARPREG risk factors equals what % risk of maternal cardiac complications?
27%
What medication that many single ventricle patients are on is contraindicated in pregnancy?
ACEi
True or False: ASA is safe to continue during pregnancy?
True
What must be ruled out in an adult Fontan patient with a HR >100 beats/min?
Intra-atrial re-entrant tachycardia
What should be done for post-operative re-entrant atrial tachycardia in a hemodynamically stable patient?
Atrial overdrive pacing
*Especially if have temporary wires in place
What are 3 ways you can perform post-operative atrial overdrive pacing?
- Transesophageal lead
- Transvenous lead
- Epicardial lead
How is atrial overdrive pacing done?
Bursts of pacing starting at 20msec faster than clinical tachycardia and gradually increasing rate/length of pacing bursts until tachycardia is terminated or rate felt to be too fast
-Can also use decremental pacing or pacing drive trains followed by a premature beat
What is decremental pacing?
Gradually increasing the pacing rate while pacing until tachycardia termination is seen
What a pacing drive train followed by a premature beat?
Pacing faster than the tachycardia cycle length followed by an extra stimulus
To successfully terminate a reentrant atrial tachycardia, the pacing rate must be how much faster than the atrial rate?
10-20%
What is a risk of atrial overdrive pacing, especially is the pacing rate is fast (200msec or less)?
Atrial fibrillation
How would adenosine or vagal maneuvers be helpful in atrial tachycardia?
They could unmask flutter waves is diagnosis was unclear
-They would not terminate the tachycardia
What would be the treatment of choice for an atrial tachycardia in a hemodynamically unstable patient?
DC cardioversion
*Also consider if no temporary pacing wires even if hemodynamically stable
What are downsides to DC cardioversion?
- More painful
- Potential dislodgement of support structures in a post-op patient
Chest pain, ECG with diffuse ST segment elevations and PR depression, elevate acute phase reactants and troponin levels?
Acute myopericarditis
True or False: Patients with IBD (especially UC) develop myocarditis or pericarditis during the course of their disease?
True
What IBD medications can cause a drug reaction leading to pericarditis or myocarditis?
5-ASA compounds like mesalamine and sulfasalazine
When does pericarditis associated with 5-ASA usually occur?
Within a few weeks after initiation of therapy
How do you manage pericarditis associated with 5-ASA?
Stop 5-ASA
*Should not switch from 1 5-ASA to the other either, can result in relapse and more hemodynamically significant disease
True or False: Low-dose (0.2-0.5mg/kg/day) prednisone is as efficacious as high-dose steroids in the treatment of pericarditis?
True- Also reduces risk of serious side effects (Cushingoid syndrome, recurrence rate, disease-related hospitalizations)
True or False: Patients with pericarditis who are treated with higher dose steroids have lower event-free survival?
True- Events including cardiac tamponade and development of constrictive pericarditis
Syncope, sensorineural hearing loss, short, multiple lentigines and cafe au lait spots, pectus excavatum, LVOT murmur, ECG with LVH and strain, chest wall abnormalities, mild learning disorders?
Noonan syndrome with multiple lentigines
Describe the lentigines in Noonan syndrome with multiple lentigines?
- Mainly on face neck, upper chest
- Spare mucosa
*May be preceded by cafe au lait spots
What was Noonan syndrome with multiple lentigines formerly called?
LEOPARD
What is the pneumonic for LEOPARD or Noonan syndrome with multiple lentigines?
- Lentigines
- ECG abnormalities
- Ocular hypertelorism
- Pulmonic stenosis
- Abnormal genitalia
- Growth retardation
- Sensorineural deafness
What is the most common cardiac abnormality in patients with Noonan syndrome with multiple lentigines?
HCM
*Detected in up to 80% of patients with a cardiac defect
Describe the HCM seen in Noonan syndrome with multiple lentigines
- Asymmetric
- Progressive
- Involves IVS
- Significant LVOTO in up to 40% cases
- PS seen in 20-25%
What are other cardiac abnormalities besides HCM seen in patients with Noonan syndrome with multiple lentigiens?
- Aortic valve abnormalities (mild AR, discrete subaortic stenosis, AV dysplasia)
- MVP
- Coronary abnormalities
- Apical aneurysm of LV
- LVNC
- Isolated LV enlargement
- AVSD
- VSDs
What is another name for the group of genetic syndromes called the Ras/mitogen-activated protein kinase (MAPK) pathway disorders or RASopathies?
Neuro-cardio-facial-cutaneous syndromes
What conditions have the Ras/MAPK pathway protein mutations been associated with?
- Noonan syndrome
- Gingival fibromatosis type 1
- Neurofibromatosis type 1 (NF1)
- Capillary malformation-arteriovenous malformation
- Costello syndrome
- Autoimmune lymphoproliferative disorder
- Cardiofaciocutaneous syndrome
- Legius syndrome
What are some of the shared features of the Ras/MAPK protein pathway mutation disorders?
- Facial anomalies
- Cardiac defects
- Cutaneous and ocular abnormalities
- Growth deficits
- Varying degrees of neurocognitive impairment
- Increased risk of cancer
85% of patients with Noonan syndrome with multiple lentigines have mutations in what gene?
PTPN11
Large mouth, small wart-like growths that may develop around the nose/mouth, poor grwoth, delayed intellectual development, hypotonia, increased risk of tumors (papillomas), HCM?
Costello syndrome
Multiple lentigines, myxomas (cardiac and cutaneous), multiple endocrine and nonendocrine tumors, blue nevi?
Carney complex
What two syndromes are now classified as Carney complex?
- LAMB (lentigines, atrial myxomas, myxoid neurofibromas, ephelide)
- NAME (nevi, atrial myxoma, blue nevi)
Where are the lentigines and blue nevi most commonly seen in Carney complex?
Perioral (vermillion borders of lips) and periocular (lacrimal caruncle and inner/outer canthi)
What % of patients with Carney complex have cardiac or cutaneous myxomas?
- Cutaneous (30-55%)
2. Cardiac (20-40%)
True or False: Cardiac myxomas associated with Carney complex can lead to embolic strokes and heart failure?
True
HCM and a cardiac myxoma both may present with that?
Syncope
Describe the murmur of a myxoma
Mid-diastolic murmur and low-pitched tumor plop
*Symptoms/presentation vary with myxoma location
Any patients with cardiac myxomas (especially recurrent) and cutaneous manifestations should have what ruled out?
Carney complex
Cafe au lait spots and axillay, underarm and groin freckling?
Neurofibromatosis type 1
The vasculopathy associated with NF1 produces what?
- Vascular stenosis
- Aneurysms
- Pseudoaneurysms
- Rupture
- Fistula formation
- Moyamoya
When is NF1 vasculopathy usually diagnosed?
Childhood or early adulthood
What is the most common vessel involved in vasculopathy with NF1?
Renal arteries (but most patients have multiple affected vessels)
What can be seen in association with renal artery stenosis in NF1 vasculopathy?
Abdominal aortic coarctation
What is the most common CHD seen in NF1?
PS
*Rare reports of conotruncal and left heart obstruction defects like AS or CoA
What is the % incidence of CHD in NF1?
2%
What needs to be monitored in a NF1 patient with HTN?
Thoracic or abdominal CoA
What is the most common cardiac abnormality associated with Noonan syndrome with multiple lentigines?
HCM
Carney complex is associated with what cardiac finding?
Myxomas
What are 2 major cardiac-related concerns in NF1?
- Abdominal CoA
2. Renal artery stenosis
What is the initial non-invasive test of choice for screening patients with concern for any type of cardiomyopathy?
TTE
What cardiomyopathy may be challenging to diagnose by TTE and require a CMR?
Arrhythmogenic right ventricular cardiomyopathy
True or False: Stress testing should be part of initial TTE in anyone with a suspected cardiomyopathy?
False- may be contraindicated
*Could be helpful on subsequent studies to see if there is any exercise-induced gradients
Stress testing isn’t recommended in patients with HCM with a peak instantaneous Doppler gradient > what?
50mmHg
When is CMR useful in the diagnosis of a cardiomyopathy?
- If TTE inconclusive
- Concern for RV function or abnormalities
- LGE can assess for scarring (especially for risk stratification in HCM)
- Differentiate etiologies of secondary cardiomyopathies (Fabry, amyloidosis, LAMP2 in HCM, myocarditis in DCM)
When is CT/CTA useful in assessment of a cardiomyopathy?
- If there is a specific question about coronary origins, ostia or course
- If there is concern for CoA or obstruction in thoracic aorta not well seen by echo (can also use CMR)
What is the screening test of choice for the diagnosis of DCM, HCM or RCM?
TTE
LQTS affects approximately how many people?
1/2500
What does LQTS predispose to?
Ventricular arrhythmias (Torsades)
What is the most common type of LQTS?
LQTS Type 1
What is the mutation associated with LQTS type 1?
KCNQ1
When do patients with LQTS type 1 experience arrhythmias?
Exercise (swimming)
When do patients with LQTS type 2 experience arrhythmias?
Sudden loud noises, extreme emotions, being startled
When do patients with LQTS type 3 experience arrhythmias?
Sleep
What is the 1st line management of patients with LQTS?
B-blockers (nadolol) and lifestyle modifications
True or False: B-blockers significant reduce mortality in patients with LQTS?
True
What should be done for a patient with LQTS and recurrent syncope despite maximal B-blocker therapy?
ICD (Class IIA)
*Other option is left cardiac sympathetic denervation
What are acute risks during implantation of an ICD?
- Bleeding
- Infection
- Perforation
- Lead dislodgement
- Pneumothorax
- Hemothorax
What accounts for the highest % of long-term complications in patients with an ICD?
Inappropriate shocks
Inappropriate shocks from an ICD are linked to the development of what?
PTSD
What is a relative contraindication for placement of a transvenous ICD?
Intracardiac shunting due to risk of stroke
*Need to have imaging to assess for any shunting prior
What anti-arrhythmic class are amiodarone and sotalol?
Class III
Why are amiodarone and sotalol contraindicated in patients with LQTS?
Prolong the QT interval by prolonging cardiac depolarization
What are the classic ECG findings in an infant with tricuspid atresia?
- LAD
- RAE
- Prominent left sided forces (like a deep S in V1)
How would an infant with tricuspid atresia, normally related great vessels and a restrictive VSD present?
- Desaturated (decreased PBF)
- High-frequency holosystolic murmur
- Preserved systemic output
How would an infant with tricuspid atresia, D-TGA and restrictive VSD present?
- Decreased systemic output, cardiogenic shock
- Desaturation
What is the 3rd most common form of cyanotic CHD in newborns?
Tricuspid atresia
*Although uncommon overall based on prevalence
What is the typical surgical approach to tricuspid atresia?
Staged surgeries to a Fontan palliation
In what situation might cyanosis be difficult to appreciate?
In a dark-skinned infant
What is type I tricuspid atresia?
Normally related great arteries
*PBF dependent on flow through hypoplastic RV or L-R flow through PDA
What is type II tricuspid atresia?
D-TGA
*Systemic aortic flow dependent on flow through hypoplastic RV or R-L flow through PDA
What differentiates type I v. type II tricuspid atresia?
Great artery orientation
I: Normally related
II: D-TGA
*Further broken down based on presence of VSD and degree of PS/PA
What is type III tricuspid atreisa?
cc-TGA
Where is the location of the VSD in tricuspid atresia?
Muscular portion of septum
*Particularly susceptible to development of VSD restriction
What type of atrial shunting is present in all cases of tricuspid atresia?
R-L
True or False: A restrictive ASD is uncommon in tricuspid atresia?
True
*When does happen, significant hepatomegaly and decrease pulmonary and systemic blood flow- needs urgent intervention
How does tricuspid atresia with normally related great arteries and a restrictive VSD present?
Marked cyanosis in an otherwise asymptomatic young infant
How does tricuspid atresia with a restrictive atrial septal defect present?
Marked hepatomegaly and decreased systemic out put (uncommon)
What are the 2 broad categories of coronary artery fistulas?
Proximal
Distal
Describe a proximal coronary artery fistula
- Fistulous communication arises from proximal main epicardial coronary artery and terminates in a cardiac chamber
- Feeding epicardial coronary artery is dilated up to origin of fistulous communication and remainder of epicardial artery and branches are normal in size
Describe a distal coronary artery fistula
- Fistulous communication is at the terminal end of the epicardial coronary artery- dilation of entire length of coronary artery
- Normal coronary artery branches arise from dilated/aneurysmal epicardial coronary artery
In a distal CAF, where is surgical patch closure, surgical ligation or transcatheter device closure done?
At the site of drainage to the RV
After closure of a CAF, what are patients at increased risk for?
Proximal clot propagation and thromboembolism (relative stasis of blood in the remaining dilated coronary artery)
True or False: ASA alone is insufficient to prevent clot formation in large/dilated coronary arteries?
True
How long should patients with a CAF and dilated epicardial artery receive anticoagulation for?
6-12 months after closure (time for conduit epicardial artery to remodel and decrease to normal size)
*ASA used indefinitely, but stop warfarin or lovenox after 6-12 months
What is the typical anticoagulation therapy for patients after CAF closure?
-Warfarin (INR 2-3) or Lovenox + ASA
or
-Clopidogrel + ASA
How does nitroglycerin work?
Improves coronary blood flow by reversing/inhibiting coronary vasospasm
Treating a symptomatic, large, distal-type CAF prevents the risk of what?
Angina Myocardial infarction Endocarditis Arrhythmias Aneurysmal dilation Rupture
What can lead to myocardial infarction following device closure of a large distal-type CAF?
Proximal clot propagation
What is recommended to prevent distal vessel sasis and clot propagation following device closure for CAF?
Dual therapy anticoagulation
- ASA + Warfarin
- ASA + Lovenox
- ASA + Clopidogrel
How is a transcatheter closure of an ASD usually performed?
Through the femoral vein and IVC
What is an interrupted IVC the result of?
- Absence of the hepatic IVC segment
- Azygous continuation into the right or left SVC (or bilateral SVCs)
What circumstance is an interrupted IVC most common in?
Heterotaxy with left atrial isomerism (86%)
*Can occur as an isolated defect though
What is seen on echo in interrupted IVC?
- Absence of an IVC draining into the RA
- Presence of a large venous vessel whose flow is directed superiorly
In the setting of an interrupted IVC, what are other options for ASD device closure?
- Transhepatic
- Jugular
- Transazygous
Where do the systemic veins develop from?
-Connection and involution of the 3 paired venous systems: Cardinal, umbilical, vitelline
Where do the cardinal, umbilical and vitelline veins drain to?
Ipsilateral horns of the sinus venosis
When do congenital abnormalities of the systemic veins develop?
During the first 8 weeks of gestation
What causes congenital abnormalities of the systemic veins?
Abnormal drainage or failed involution of the 3 paired venous systems (cardinal, umbilical, vitelline)
Systemic venous anomalies are more common in patients with what syndrome?
Heterotaxy
- Often seen with other congenital cardiac defects
- May occur in isolation
True or False: Systemic venous anomalies usually do not lead to any clinical symptoms
True
*But can affect cardiac interventional procedural or surgical planning/success- Need imaging prior to intervention to identify the SVC/IVC/innominate vein
How can the systemic veins be evaluated?
- Echo first line
- May need MRI or CT if suboptimal windows or for confirmation
True or False: A persistent L-SVC usually occurs in the presence of a normal R-SVC?
True
What is the typical cause of a persistent L-SVC?
Failed involution of the left anterior and common cardinal veins
What % of patients with other congenital cardiac abnormalities have a persistent L-SVC?
3-4%
What is the % incidence of a persistent L-SVC as an isolated finding with no other congenital cardiac abnormalities?
0.5%
In 90% of cases of a persistent L-SVC, where does it drain?
Through a dilated coronary sinus to the RA
- Remainder of cases, the L-SVC drains directly to the LA through a partially or completely unroofed CS (most common in cases of heterotaxy)
- Rarely can get isolated L-SVC to dilated CS or LA w/o R-SVC
Where does the normal innominate vein course?
Anterior to aorta and then drains to the left jugular vein to the right SVC to the RA
What might the innominate vein serve as with bilateral SVCs?
Bridging vein
*Can also just have absence of the innominate vein with bilateral SVCs
What circumstance is it important to determine whether there is a bridging vein in the setting of bilateral SVCs?
- Single ventricle patients
- Need to determine if bilateral cavopulmonary anastomosis needed (bridging vein absent) or if one of the SVCs can be surgically ligated (bridging vein present)
Describe the course of a retroaortic left innominate vein?
Drains left jugular vein to right SVC normally, but courses behind/underneath aorta
What patients is a retroaortic left innominate vein more common in?
RVOTO (like ToF)
What could a retroaortic left innominate vein be confused with on imaging?
Pulmonary artery
Persistent L-SVC
What hemodynamic change is poorly tolerated in supravalvar aortic stenosis because it contributes to decreased coronary perfusion?
Decreased SVR
What causes supravalvar aortic stenosis?
Discrete area of narrowing at the level of the STJ or long segment narrowing of the ascending aorta
What types of patients most commonly get supravalvar aortic stenosis?
Williams syndrome or other types of elastin arteriopathies
How does supravalvar AS put patients at risk for ischemia?
- LVH (if obstruction is significant) which increases myocardial O2 demand
- Abnormal elastin in aorta leads to decreased distensibility/elastic recoil, limiting coronary blood flow
- Coronary artery tissue abnormal and may limit flow/autoregulation
- Thickened tissue causing supravalvar narrowing can also cause obstruction of coronary ostia by adhering to walls of sinus
How could an anesthetic agent lead to ischemia in a patient with supravalvar AS?
- Decrease SVR, which decreases CPP which can cause ischemia
- Depress myocardial function
- Cause tachycardia and increased myocardia oxygen demand
What are 3 anesthesia goals for patients with supravalvar aortic stenosis?
- Avoid hypotension and keep preload up
- Avoid agents that decrease SVR
- Avoid agents that depress myocardial function
What is the systolic PA pressure estimate in an infant with a large complete AVSD and no obstruction to pulmonary outflow?
At or near systemic pressure
What is the differential diagnosis for a SVT with stable RR interval, 1:1 AV relationship and long PR interval?
- Atrial tachycardia (ectopic, microreentrant or macroreentrant)
- AV reciprocating tachycardia
- Atypical AV nodal reentrant tachycardia
Does frequent 2nd degree AV block point towards SVT due to atrial tachycardia, or AVRT?
Atrial tachycardia
Why does 2nd degree AV block frequently occur in patients with atrial tachycardia?
- The atrial cycle length is often shorter than that of the refractory period of the AV node
- AV node isn’t part of the circuit, so the tachycardia can continue in the setting of 2nd degree AV block
True or False: Any 2nd degree AV block that occurs in the setting of AVRT would result in termination of the tachycardia?
True- AV node is an integral part of circuity
*2nd degree AV block can occur in AVNRT w/o terminating tachycardia, but this is uncommon
SVT occurs in how many people with structurally normal hearts?
1 in 500
What % of SVT is caused by an atrial tachycardia?
10%
What are the 4 mechanisms of atrial tachycardia?
- Atrial flutter
- Macrorentrant
- Microreentrant
- Automatic/Ectopic
Prolongation of the tachycardia cycle length (and VA time) with intermittent BBB strongly suggests what?
AVRT using an accessory pathway ipsilateral to the site of the BBB
Spontaneous termination of SVT ending in an atrial event (P-wave) strongly suggests what?
AVRT or AVNRT (over atrial tachycardia)
How does a block in the AV node affect AVRT and AVNRT?
Termination of tachycardia (AV node is part of circuit)
*Doesn’t always happen in AVNRT
How does a block in the AV node affect an atrial tachycardia?
Would cause a 2nd degree AV block (AV node isn’t involved in circuit or ectopic focus)
Why is it rare for an atrial tachycardia to end with an atrial event?
There would need to be simultaneous termination of the tachycardia and unrelated AV block (very unlikely, especially with 1:1 AV conduction in SVT)
Does the presence of sudden onset/termination help differentiate between AVRT, AVNRT and atrial tachycardia?
No
What tachycardias frequently have a “warm-up/cool-down” versus sudden onset or termination?
EAT
If 2nd degree heart block is seen without affecting the atrial rate, what should be diagnosed?
Atrial tachycardia
Very rarely could this be AVNRT
Termination with an atrial event almost completely excludes what type of SVT?
Atrial tachycardia (typically in the setting of 1:1 AV conduction)
What type of SVT is suggested with cycle length lengthening and BBB?
AVRT
What type of SVT is suggested with a warm-up and cool-down?
EAT
What is the classic echo finding for Ebstein?
Apical displacement of the hinge point of the septal leaflet of the tricuspid valve
What is the displacement index related to Ebstein anomaly?
Measured distance from insertion point of the anterior mitral leaflet to the hinge point of the tricuspid septal leaflet corrected for BSA
A displacement index > what indicates Ebstein?
8mm/m2
What is the most common associated abnormality in Ebstein anomaly?
ASD (permits interatrial shunting which can cause cyanosis)
What are other associated cardiac defects/problems with Ebstein besides an ASD?
PS, PA, functional PA, VSD, MVP, LVNC, bicuspid AoV, AV atresia, CoA, PDA
What is the severity of tricuspid regurgitation in most cases of Ebstein?
Severe
Embryologically, what causes Ebstein?
- Failure of delamination of the tricuspid valve leaflets (primarily septal and inferior/posterior leaflet)
- Leaflets don’t fully separate from underlying ventricular wall which causes apical displacement of the septal leaflet and anterior rotation of the leaflet tissue towards the RVOT
In the most severe cases of Ebsteins, where is the septal leaflet of the tricuspid valve?
RVOT- may not see the leaflet in a 4C view because it is rotated for far anteriorly
Age at presentation of Ebsteins correlates to what?
Severity of tricuspid valve disease
True or False: Ebsteins diagnosed in utero (especially <32 weeks) is associated with high perinatal mortality?
True
Why can Ebstein present with cyanosis in infancy?
Limited flow through RV and severe TR causes R-L atrial shunting
*As PVR falls with time, may get improvement in cyanosis
How might patients with mild Ebstein present?
Exertional fatigue, murmur, arrhythmia
Ventricular preexcitation can be seen in what % of Ebstein patients?
30
Post-op bleeding can be placed into what 2 categories?
- Coagulopathic
2. Surgical
What are things that can contribute to coagulopathic post-op bleeding in an infant?
- Priming of CPB circuit causes a dilutional coagulopathy
2. Decrease activity of platelts after CPB
What testing is important to obtain with concern for post-op bleeding due to a coagulopathic cause
PT, INR, PTT, fibrinogen, heparin assay, activated clotting time, thromboelastography
What can get given to help with post-op coagulopathic bleeding?
FFP and platelet transfusions
Bleeding approaching what amount with normal coags is likely surgical in nature and needs surgical attention?
10mL/kg/hr
What should you worry about in a post-op patient who had moderate-severe bleeding from a chest tube that suddenly stops and is associated with poor hemodynamics?
Clot in chest tube or malfunction in chest tube
- Can cause hemothorax leading to tamponade physiology
- Needs surgical intervention if can’t get tube to drain
What else needs done as part of the workup for someone with symptoms consistent with vasovagal syncope, no concerning features in the history, normal PE and normal ECG?
Nothing
What is the most common etiology of syncope?
Neurocardiogenic
When is a common time for the first episode of neurocardiogenic syncope?
Adolescence
What happens in neurocardiogenic syncope?
Various triggers cause venodilation and venous pooling with a decrease in CO and insufficient cerebral blood flow
- Decreased BP seen by baroreceptors which try to cause a sympathetic response to increase HR and BP, but in neurocardiogenic syncope, get a vagal response which inhibits sympathetic effect
- This causes more venodilation, vasodilation and lower HR
What are some triggers for neurocardiogenic syncope?
- Position change
- Prolonged sitting or standing
- Pain
- Medical situations
- Micturition
- Vagal stimulation
- Hairbrushing
What are typical symptoms of neurocardiogenic syncope?
- Prodrome with lightheadedness, nausea, flushing, diaphoresis and blurring/blackout of vision followed by loss of tone/consciousness
- Loss of tone/consciousness is brief (<2 min) and self-resolving
- May feel tired or lightheaded after event
What should you do for workup of suspected neurocardiogenic syncope?
- History
- FHx: Especially channelopathies, arrhythmias, syncope, sudden death and seizures
- PE
- ECG
Further testing beyond an ECG isn’t needed with a story consistent with neurocardiogenic syncope and what 4 criteria?
- Doesn’t occur during exercise or as a result of a startle or loud noise
- Cardiac exam normal
- FHx negative for sudden death and inherited arrhythmias
- No ECG abnormalities
True or False: Tilt table testing isn’t routinely done in evaluation of neurocardiogenic syncope
True
Can a tilt-table test determine if a syncopal episode was due to neurocardiogenic syncope?
No- only that a person is at risk for neurocardiogenic syncope
*May be helpful if diagnosis is unclear
What is the management for patients with frequent episode of neurocardiogenic syncope?
- Fluid
- Salt
- Counterpressure maneuvers
- Regular exercise
- Meds- Florinef or midodrine
What is the most common type of syncope in children?
Neurocardiogenic
CHD (supravalvar AS), hypercalcemia, skeletal anomalies, renal anomalies, cognitive defects, eflin facies, social personality?
Williams
What are the cardiac manifestations in Williams?
- Supravalvar AS (sometimes can get a bicuspid AoV, but not typically)
- Supravalvar PS
- Coronary artery ostial stenosis (risk for SVD)
True or False: You would expect to hear a click in supravalvar aortic stenosis?
False
What is the Coanda effect?
Excess blood flow directed towards innominate artery may result in elevated BP in RUE
What is the progression of supravalvar AS v. supravalvar PS with time as seen in William’s syndrome?
- AS worsens
- PS improves
What is the most common gene mutation in Williams?
Deletion at 7q11.23
What gene is abnormal in Williams?
7q11. 23- What makes elastin (ELN)
- ELN encodes the protein tropoelastin which join to make mature elastin
The gene mutation seen in Williams causes what problem?
They don’t make as much elastin- Large blood vessels with abnormal elastic fibers are often thicker and less resilient… they can narrow and increase resistance to blood flow (what causes supravalvar AS/PS)
What is seen with a deletion of 8p23?
ASD/VSDs, GU anomalies, abnormally formed ears, minor hand anomalies
What is seen with monosomy 18q?
ASD/VSD and PS
-Can also get cleft palate and GU anomalies
Hypocalcemia, immunodeficiency, CHD (ToF, Truncus, VSD/IAA type B)?
DiGeorge, 22q11
What results from a defect in elastin production, usually from a deletion on the long arm of chromosome 7 (7q11.23)?
Williams
Cardiac findings in Williams?
Supravalvar AS
Supravalvar PS
Coronary artery ostial stenosis
Which gets worse with time in Williams, supravalvar AS or PS?
AS (PS may improve)
What puts patients with Williams at higher risk for SCD?
Coronary artery ostial stenosis
TAPVR s a defect that involves the embryological development of what?
Splanchnic venous plexus
How does normal development of pulmonary veins occur?
- Common splanchnic plexus drains through paired common cardinal, umbilical and vitelline veins (no direct connection to heart)
- Later in development, the common pulmonary vein invaginates through the left atrial wall and establishes a connection to the heart
- Then the primitive cardinal, umbilical and vitelline veins become unnecessary for pulmonary venous drainage
How does TAPVR occur embryologically?
Failure of LA to link to the pulmonary venous plexus… results in a retention of the connections to the primitive cardinal and umbilico-vitelline drainage systems
What are the 4 types of TAPVR?
- Supracardiac
- Cardiac
- Intracardiac
- Mixed
What is the most common type of TAVPR?
Supracardiac (40-50% of cases)
Describe supracardiac TAPVR
Pulmonary veins drain via a left vertical vein to the innominate vein
True or False: Supracardiac TAPVR is rarely obstructive
True- Frequently unobstructed or mildly obstructed
*Can become more significantly obstructed where vertical vein passes between the left mainstem bronchus and either the LPA or aorta
What is the most common site of connection to the heart in cardiac TAPVR?
Coronary sinus
True or False: Obstruction is rare in cardiac TAPVR?
True
How often does cardiac TAPVR occur?
18-31% of cses
Describe infracardiac TAPVR
Descending vertical vein penetrating the diaphragm and connecting with a vessel of the portal venous system
Where is obstruction most common in infracardiac TAPVR?
At the point of intersection of the vertical vein and portal venous system
*Very common
How often does infracardiac TAPVR occur?
13-24% of cases
What is mixed TAPVR?
2 or more sites of anomalous venous return
5-10% of cases
What two things should you consider in a newborn with severe hypoxemia, hemodynamic compromise and RV dysfunction?
PPHN and TAPVR
What must you ensure prior to a newborn being started on ECMO in the setting of severe hypoxemia, hemodynamic compromise and RV dysfunction?
That it isn’t TAPVR
What is the difference on CXR between PPHN and TAPVR?
- PPHN: Oligemia on CXR
- TAPVR: Congested appearance on CXR
What are echo findings that should clue you in to the diagnosis of TAPVR?
- Severely dilated and poorly functioning RV (can also be seen in PPHN)
- Exclusive R-L atrial level shunting (can also be seen in PPHN)
- Blood flow in hepatic veins moving away from heart (think infracardiac with obstruction)
- Vessel near IVC with blood flow in opposite direction (vertical vein)
- Inability to demonstrate pulmonary veins returning to the LA
What is one of the few true cardiothoracic surgical emergencies?
Obstructed TAPVR
Why could iNO worsen a patients hemodynamics with obstructed TAPVR?
Dilated pulmonary vessels proximal to obstructed veins worsening interstitial edema
Should PGE be used in obstructed TAPVR?
Controversial
- Vasodilatory effects on pulmonary vasculature may worsen heart failure (limited return of blood from pulmonary veins)
- PDA may give a pop-off for an RV that is very hypertensive
*Many places started PGE and continue infusion until surgery
Long QT syndrome affects how many people?
1/2500
What does LQTS predispose patients to?
Ventricular arrhythmias (torsade)
What is the most common type of LQTS?
Type 1
What is the gene mutation associated with LQTS1?
KCNQ1
*Potassium channel mutation
When do patients with LQTS1 often develop their arrhythmias?
While swimming
What is the gene associated with LQTS2?
KCNH2
When do patients with LQTS2 often develop their arrhythmias?
- Loud noises
- Extreme emotions
- Startled
When do patients with LQTS3 often develop their arrhythmias?
Sleep
What is the gene mutation with LQTS3?
SCN5A
A mutation in MYH7 predisposes someone to what?
HCM
What is the most common cause of sudden death in young athletes in the US?
HCM
What causes sudden death in HCM patients?
Ventricular arrhythmias
What are risk factors for sudden death in people with HCM?
- Severe septal hypertrophy (>30mm)
- Unexplained syncope
- NSVT
- FHx sudden death
- Abnormal BP response to exercise
A mutation in PKP2 predisposes someone to what?
ARVC
What condition would a patient develop fatty infiltration of the myocardium with increased risk for ventricular arrhythmia and sudden death?
ARVC
When do ARVC patients often develop symptoms?
3-4 decade of life
*Event can occur before this
What are common ECG findings in ARVC?
- Epsilon waves (terminal notching) in V1
2. T-wave inversion in V1-V3
How do you assess for fatty infiltration in ARVC?
CMR
What does a mutation in RYR2 predispose to?
CPVT
What type of tachycardia is common in CPVT patients during high adrenergic states?
Bidirectional ventricular tachycardia
True or False: Baseline ECG in a patient with CPVT are normal?
True
How to you assess for CPVT?
Exercise stress test or epinephrine challenge- Can bring out bidirectional ventricular tachycardia
When do ventricular arrhythmias tend to occur in Brugada patients?
- Sleep
- Febrile illness
- Hyperthermia
What is one of the most common gene abnormalities in Brugada?
Loss of function in SCN5A
What is the classic ECG finding in Brugada?
RBBB with ST elevation in V1-V3
What are the most common genetic causes of sudden cardiac death in the young?
- HCM
- ARVC
- LQTS
- CPVT
- Brugada
The flow of fluid through a tube is described by what?
Poiseuille’s law
What describes how pressure difference across a tube and resistance to flow though the tube affects the flow of fluid through the tube?
Poiseuille’s law
What is Poiseuille’s law?
Flow = (Pressure difference * radius 4)/(Viscosity * Length)
A change in what factor will increase the flow of blood through a shunt most significantly?
The diameter of the shunt (i.e. a 3.5mm BTT v. 4mm BTT)
How does a right pressure difference effect flow?
Increase in pressure will result in increase in flow
How to viscosity and length effect flow?
Inversely proportional, so an increase in either will result in a decrease in flow
What is most sensitive to changes in the radius of a vessel and have the largest effect on flow through that vessel?
Resistance
What is the equation for resistance?
(Viscosity * Length)/Radius ^4
What is flow equal to?
Change in pressure / Resistance
What should be adjusted on a pacemaker for atrial oversensing?
Increase the atrial sensing threshold (to try to filter out the noise that is being oversensed)
If you see pacing in the atria and ventricle, what does this tell you about the pacing mode?
Can’t be a single-chamber mode like AAI or VVI
If you see atrial sensing with inhibition of atrial pacing, what does that rule out?
Asynchronous mode (like DOO)
If you see atrial tracking (clear P-waves with paced ventricular event and stable PR interval, as well as variation in paced ventricular rate) what mode is the person likely in?
DDD or DDDR
Is a pacemaker-mediated tachycardia typically regular or irregular?
Regular
What is part of the circuit in pacemaker-mediated tachycardia?
- Ventriculoatrial conduction
- Sensed AV delay
If you paced DDD and at high sinus rates, what can you have?
Irregularity due to upper rate behavior
What does upper rate behavior in DDD at a high sinus rate look like?
Regularly irregular with grouped paced beats at the same interval (upper tracking interval) before a blocked beat (pacemaker Wenckebach)
What does atrial oversensing result in?
Ventricular “overpacing”
-Have atrial sensing with a paced ventricular beat when there isn’t a corresponding atrial event on ECG
What is done to fix atrial oversensing?
Increase the sensing threshold (makes the lead less sensitive) to let the pacemaker filter out noise and still sense the true P wave
Increasing PVARP on a pacemaker can be helpful in what situations?
- Tracked PACs
- Pacemaker-mediated tachycardia
How do you fix upper rate limit activity?
Increase upper tracking rate
What id done to fix loss of ventricular captrue?
Increase ventricular threshold
What should an irregular paced ventricular rhythm raise suspicion of in a patient in DDD pacing?
- Atrial tachycardia/fibrillation
- Tracked PACs
- Upper rate behavior
- Atrial oversensing
What is a failure of septation between the aortic and pulmonary trunks?
AP window (rare with 0.2% prevalence in CHD)
What is AP window often associated with?
Other CHD like IAA (50% of cases)
How are AP windows classified?
By location
Where is a type 1 AP window?
Proximal in relation to semilunar valves
Where is a type 2 AP window?
Distal in relation to semilunar valves
Where is a type 3 AP window?
Total (includes largest defects)
What is a type 4 AP window?
Indeterminate (neither close to semilunar valves or branch PAs)
What is the lack of connection between the ascending and descending aorta?
IAA
How is IAA classified?
Location of interruption
Where is a type A IAA?
Distal to left subclavian artery
Where is a type B IAA?
Between the left carotid artery and left subclavian artery
Where is a type C IAA?
Between the innominate artery and left carotid artery
What is the most common type of IAA?
B (50-70%)
Then A (30-45%) and C (<5%)
What type of IAA has the strongest association with an AP window?
A
*B can have it, but less common
What is a type B IAA most likely to be associated with?
VSD and 22q11.2 deletion
How do simple (no other associated cardiac defects) AP windows present?
- L-R shunt lesion
- Usually in first few weeks after birth
- Defect typically large enough to result in pulmonary HTN and congestive heart disease
How does AP window + IAA typically present?
Ductal-dependent systemic blood flow lesion
*Can get differential cyanosis and pulses, metabolic acidosis, shock if PDA closes
What else do you nee to look for if you have a type A IAA?
AP window
What is confirmed when 2 lumina separated by an intimal flap are visualized in the aorta?
Aortic dissection
What are some positive criteria for an aortic dissection?
- Complete obstruction of a false lumen
- Separation of intimal layers from a thrombus
- Shearing of different wall layers during aortic pulsation
When is a tear frequently seen in an aortic dissection?
When there is disruption of the flap continuity with fluttering of the ruptured intimal borders.
What causes of reverberation artifact?
- Within reflected wave arising at transducer, part of energy concerted to electrical energy
- Another part of wave is reflected on transducer surface and will propagate away from transducer like it was another US transmission
- Secondary transmission will propagate in a way similar to that of the original pulse- means it if reflected by the tissue and detected again
- Higher order reflections are reverberations and cause ghost structures in the image
When does reverberation artifact typically occur?
When there are strongly reflecting structures in an image like ribs or pericardium
What causes a side lobe artifact?
- Most of US energy is centered on axis in from of transducer (main lobe)
- Part of energy also directed sideways/off-axis (side lobe)
- Reflections from side lobes much smaller in amplitude than ones from main lobe and can often be ignored
- Can get artifact when main lobe is in an anechoic region (like a LV cavity) which causes the contribution of the side lobes to become more significant
When is a side lobe artifact typically seen?
When the dominant structure in the image is relative large and anechoic (like a dilated chamber)
The most common cause of low HDL levels are associated with what?
Insulin resistance
What results in an influx of free fatty acids to the liver, overproduction of very low density lipoprotein with an elevated triglyceride level and increased small LDL particles?
Insulin resistnace
In patients with diabetes, what is the main goal in order to decrease CV risk in adulthood?
Lowering the LDL cholesterol level
The Friedewald formula for calculated LDL can’t be used when triglyceride levels are above what number because it underestimates the LDL cholesterol level?
400mg/dL
Significantly elevated triglyceride levels increase the risk of what?
Pancreatitis
If you need to target a significantly high triglyceride level, what is the best medication to do so?
Fenofibrate - Lowers triglyceride level by 20-50%
What are the 2 fibrates available in the US?
Fenofibrate and gemfibrozil
What is the main concern with fibrates?
Myopathy- Must monitor muscle enzyme levels closely
*As monotherapy, fibrates have a 5-fold higher risk of myopathy than statins
What two cholesterol medications are contraindicated to use together?
Gemfibrozil + Statin
- 33-fold higher risk of myopathy compared to fenofibrate alone
- Gemfibrozil increases statin level and increases myopathy risk
If you have an elevated triglyceride level that is still <500 with a normal LDL, what is reasonable medical management?
2g/day Fish oil
What can a bile acid sequestrant exacerbate?
Hypertriglyceridemia
How does hyperglycemia increase the risk of arteriosclerosis in diabetic atients?
By raising levels of cholesterol and enriched apolipoprotein B
Triglyceride levels greater than what can result in underestimation of LDL?
400mg/dL
Triglyceride levels > what puts patients at increased risk of pancreatitis?
1000mg/dL
The combination of gemfibrozil and a stain increases the risk of what?
Rhabdomyolysis
What is helpful in treating moderately elevated triglyceride levels?
Fish oil
Patients with pre-excitation are at risk for developing what 2 types of arrhythmias?
- SVT
2. A-fib
What causes the risk of sudden death in patients with pre-excitation?
AF that conducts rapidly through the accessory pathway which then triggers ventricular fibrillation
What determines if A-fib can lead to ventricular fibrillation in pre-excitation?
Conduction properties of the pathway
What are features of the pathways that have increased risk for A-fib leading to ventricular fibrillation in pre-excitation?
- Very rapid antegrade conduction
- In A-fib, shortest pre-excited R-R interval <250msec
How can risk stratification for patients with pre-excitation be done?
- Exercise stress test
- EP study
What findings on exercise stress testing indicate that a pathway is low-risk in pre-excitation?
- Sudden loss of pre-excitation in 1 beat
* Cannot be gradual to be considered low-risk
What does sudden loss of pre-excitation on stress testing indicated
Accessory pathway doesn’t conduct well antegrade and cannot conduct a-fib rapidly to lead to ventricular fibrillation
What does gradual loss of pre-excitation indicate on an exercise stress test?
Possible improved conduction through the AV node secondary to increased catecholamines
-More to do with AV node response to exercise and doesn’t mean that AP can’t conduct rapidly during atrial fibrillation… pathway cannot be considered low risk in this instance
What is done to further risk stratify a patient if there is no sudden loss of pre-excitation in one beat during an exercise stress test?
Invasive EP studies
What is done to assess if a pathway is high risk during an EP study for pre-excitation?
A-fib is triggered and shortest pre-excited R-R interval is measured
Chest pain that is reproducible on exam is consistent with what?
Costochondritis
Negative delta waves in pre-excitation can sometimes look like what?
q wave
What % of patients with pre-excitation can have associated CHD?
10-20%
What are the classically associated congenital lesions with pre-excitation?
Ebstein, cc-TGA, HCM
Under what circumstances can you not reliably measure a QTc?
When depolarization is abnormal
What are examples of when you can’t reliably measure a QTc?
- Pre-excitation
- BBB
- Ventricular paced rhythm
What is the usual presentation of patients with LQTS?
Pre-syncope, syncope, palpitations, family history (SCD or LQTS)
What should be done for all patients found to have pre-excitation prior to clearing them to return to sports?
Risk stratify pathway with exercise stress test +/- EP study
What electrolyte abnormality increases the risk of digoxin-induced arrhythmias?
Hypokalemia
Hypomagnesemia
Hypercalcemia
*Also hypoxia and acidosis
What is the most classic arrhythmia seen in digoxin toxicity?
Atrial tachycardia in association with AV block
Besides atrial tachycardia in association with AV block, what are other arrhythmias that can be seen in digoxin toxicity?
PVCs, ventricular tachycardia (bidirectional v-tach) and isolated variable degrees of AV block
Spironolactone, carvedilol and renal insufficiency do what to digoxin levels?
Increase them (increased risk for toxicity
What are recommended digoxin levels in women/children and men?
Women/Children: 0.5-1ng/mL
Men: 0.5-0.8ng/mL
What is the primary reason to monitor digoxin levels?
To make sure they aren’t too high versus aiming for a specific therapeutic level
How does digoxin work?
Na/K ATP-ase inhibitor
- Inhibits the Na pump in myocytes
- When this is inhibited, Na temporarily increases within the cells near the sarcolemma resulting in a Ca influx via the Na/Ca exchange mechanism
- This enhances myocardial contractility, but increases arrhythmia risk
- Activates parasympathetic system resulting in slowed AV conduction and prolongation of the AV refractory period
- Inhibits the sympathetic system
- Inhibits renin release in the kidney (decreased activity of kidney Na pump)
What is the 1/2 life of digoxin?
Long- approximately 1.5days
How is digoxin eliminated?
Renal- any impairment can cause levels to rise
What has adult research shown digoxin to beneficial for?
- Reduced hospitalizations in HF patients, goal is to reduce symptoms and hospital admissions
- Doesn’t reduce mortality
What are the recommendations for use of digoxin in pediatrics?
- Do not recommend use in asymptomatic children with reduced ejection fraction
- Can be considered for reducing symptoms with low EF, target levels 0.5-0.9, careful monitoring if on carvedilol/amiodarone or renal impairment
- Reduced risk of inter-stage mortality in single-ventricle patients
What should be monitored in patients on spironolactone?
Hyperkalemia
What effect can spironolactone and carvedilol have on digoxin levels?
Increase them
What side effects should be monitored with ACEi?
Renal function, potassium level
What is Na/K ATP inhibitor whose action results in increased Ca influx enhancing myocardial contractility?
Digoxin
What does digoxin do to the parasympathetic and sympathetic nervous system?
- Activates parasympathetic
- Inhibits sympathetic
When is the effect of digoxin on renin release in the kidney?
Inhibits renin release in the kidney
What things increase the risk of digoxin toxicity resulting in arrhythmias and conduction disturbances?
Hypokalemia, hypomagnesemia, hypercalcemia, hypoxia, acidosis, renal dysfunction
What is an important determinant in the immediate and long-term surgical outcome of truncus arteriosus?
Presence and severity of truncal valve insufficiency
What additional lesion increases the surgical morbidity in truncus arteriosus?
IAA
What is a significant risk factor for higher mortality in isolated truncus arteriosus?
Truncal valve insufficiency
Why does truncal valve insufficiency increase morbidity and mortality in truncus arteriosus?
- Longer CPB and cross-clamp time for a combined repair (there are multiple repair techniques that can be done well on a truncal valve)
- Increased need for truncal valve replacement
- Leads to ventricular dilation and hypertrophy
- Can get chronic subendocardial ischemia from inadequate coronary perfusion and ventricular failure
What is involved in truncus arteriosus repair?
Separating the systemic and pulmonary pathways by closing the VSD and placing a conduit from the RV to PA confluence
True or False: RVOTO or branch PS is a significant long-term concern in truncus arteriosus and often requires reinterventions or reoperations?
True
What types of arch anomalies can be seen in truncus?
Right arch with mirror image branching (common)
Hypoplasia of the aortic arch
IAA (usually with 22q11.2 deletion)
True or False: IAA poses a higher risk in patients undergoing repair for truncus arteriosus?
True- due to increased CPB time and cross-clamp time with combined repair
True or False: Coronary variations are common in truncus?
True- Ostial stenosis, higher origin of the coronary arteries, etc.
*Need to be mindful of this in peri-post operative periods
What would be the best medication for multifocal atrial tachycardia with mildly reduced function?
Digoxin
What is the benefit of digoxin in multifocal atrial tachycardia?
- Some effect on atrial rate
- Ventricular rate control
- Enhanced recovery of function via rate control
*Does have mild inotropic properties, but clinically in HF digoxin doesn’t actually improve function
What are the classic criteria for multifocal atrial tachycardia on surface ECG?
- At least 3 distinct P-wave morphologic findings
- Varying PP, PR and RR intervals (irregular)
- Isoelectric baseline between P waves (rules out a-fib)
- Tachycardia
What is the incidence of multifocal atrial tachycardia in pediatrics?
<1% of pediatric SVT
Overall 0.2%
In adults, multifocal atrial tachycardia is commonly associated with what?
Pulmonary or cardiac disease
*Treatment directed towards underlying comorbidity and rate control
In pediatrics, multifocal atrial tachycardia is almost exclusively seen in what groups?
Neonates and infants
When you see multifocal atrial tachycardia in pediatrics, what should you also look for?
- Acute respiratory illness (like RSV)
- Structural heart disease
*Can be seen in otherwise healthy infants though
How to infants with multifocal atrial tachycardia present?
- Often asymptomatic-
- Can have irritability to tachypnea (signs of CV compromise)
Tachycardia-induced cardiomyopathy is seen in what % of infants with multifocal atrial tachycardia?
25%
What are the proposed mechanisms of multifocal atrial tachycardia?
- Enhanced automaticity from multiple sites or one site with several exit points
- Triggered activity
What is the natural history of multifocal atrial atachycardia?
Generally self limited (especially if a structurally normal heart)…. often outgrow this by 6-12 months
What medications are used in the management of multifocal atrial tachycardia?
- Possibly none if structurally normal heart and normal function
- Most would use an AV nodal blocker like digoxin (depressed function) or BB (normal function)
- Avoid CCB in infants (often used in adults though)
- If more complete control is needed, consider amiodarone, flecainide, propafenone
True or False: DC cardioversion can convert multifocal atrial tachycardia?
False- ineffective given the mechanism of the tachycardia (triggered or automatic, not reentrant)
True or False: Adenosine will be ineffective against multifocal atrial tachycardia?
True- Tachycardia not dependent on AV node conduction
*May allow for closer evaluation of different P-wave morphologies
What should you avoid with an irregular wide QRS tachycardia?
Adenosine- May be due to pre-excited atrial fibrillation that could degenerate into ventricular fibrillation
How would an infant present with pulmonary vein stenosis leading to pulmonary HTN?
In infancy with tachypnea, recurrent pulmonary infections, cyanosis, hemoptysis and/or failure to thrive
What are some physical exam findings which would be consisdent with pulmonary hypertension due to pulmonary vein stenosis?
- Increased RV impulse
- Accentuation of pulmonary closure w/wo pulmonary ejection click
- Right sided HF (hepatomegaly)
True or False: Stenosis of the individual pulmonary veins in isolation is rare
True- Often occurs as a localized stenosis at the junction of 1+ pulmonary veins to LA or diffusely where there is tubular hypoplasia over a significant intrapulmonary and extrapulmonary distance
True or False: A lesion of pulmonary vein causing stenosis may be asymptomatic?
True
Acquired pulmonary vein stenosis can be seen what group of patients?
Former premature infants
*Also at increased risk of pulmonary HTN
Elevation in pulmonary venous pressure leads to wht?
PAH- Great number of veins obstructed and more severe obstruction = Worse pulmonary HTN
Flattening of the IVS with systolic bowing into the LV indicates what?
Presence of significantly elevated RV pressure
Describe the normal Doppler pattern of pulmonary veins
- Phasic
- Low velocity
- 2 antegrade signals (S/D waves) correlating to peak antegrade flow during ventricular systole and diastole)
- Retrograde signal (Ar wave) representing retrograde flow during atrial contraction
What Doppler pattern of the pulmonary veins would make you suspicious for obstruction?
Continuous, high-velocity flow with loss of phasicity (loss of end-systolic and end-diastolic deceleration towards baseline)
What findings on a hemodynamic cath would be suggestive of pulmonary vein stenosis?
- Pulmonary hypertension
- Elevated PA wedge pressure on affected side
- Normal LA pressure
What cath gradient is analogous to the mean gradient on echocardiogram for pulmonary vein stenosis?
Pressure gradient from PA wedge to LA
How would elevated RVEDP effect atrial shunting?
May result in a R-L atrial level shunt
Abnormalities in atrial situs may lead to a diagnosis of what?
Heterotaxy
Which atrium has the crista terminalis?
Right
What is a muscle bar that divides the sinus venosus portion of the RA from the RA appendage?
Cristal terminalis
True or False: The LA contains the crista terminalis?
False
Describe the RA appendage
Broad-based, triangular shape
Anterior relative to the left atrial appendage
Describe the left atrial appendage
Narrow-based or fingerlike
Describe the wall of the RA
- Sinus venosus portion is smooth-walled and ends at the crista terminalis
- Distal to the crista terminalis, the RA free wall is trabeculated with pectinate muscles that extend to the valve annulus
Describe the walls of the LA
Smooth walled (only trabeculations are within the LA appendage)
True or False: Venous connections to the atrial are reliable indicators of atrial morphology?
False
-Ex: L-SVC, interrupted IVC, TAPVR, PAPVR
The suprahepatic portion of the IVC and CS drainage identifies what?
Morphologic RA
The limbus of the fossa ovalis is a feature of what atrial surface?
RA
The flap of the foramen ovale is found on what surface?
LA septal surface
The crista terminalis, pectinate muscles and a broad-based appendage are defining features of what?
Morphologic RA
A narrow-based appendage and smooth-walled surface are features of what?
LA
Premature infants with BPD should be serially screened for what?
Pulmonary HTN
What are echo findings which raise concern for pulmonary HTN?
- Ventricular septal flattening (indicates RV pressure overload)
- RV enlargement or hypertrophy
- RV dysfunction
- TR > 2.5 to 3
- PI gradient than 2
What should be done next if there is echo findings concerning for pulmonary HTN?
- Cath to assess degree of pulmonary HTN and degree of vasoreactivity prior to medications
- If patient is too sick or other issues preclude a cath from being done first, can just start medication
Prior to starting medication for pulmonary hypertension, what two things should be addressed?
- Underlying pulmonary disease (Trach, inhaled steroids, bronchodilators, O2)
- Cardiovascular lesions
What is the first pulmonary hypertension medication typically used?
Sildenafil
*Use isn’t approved by FDA for kids in US and studies are limited, but use is still recommended in pulmonary hypertension guidlines
How does sildenafil work?
PDE-5 inhibitor
What is a common cause of desaturations after sildenafil dosing for pulmonary hypertension?
V/Q mismatch
-Common in patients with BPD-associated pulmonary hypertension
How can sildenafil cause V/Q mismatch?
- Given systemically it may cause dilation of the pulmonary arterioles that aren’t receiving adequate ventilation
- This creates an intrapulmonary shunt and results in hypoxia
When do desaturations after sildenafil doses typically occur?
Within 30-60 minutes, self-limited
*Observe these patients… hypoxia usually improves i a short time period once ventilation catches up to perfusion and the degree of V/Q mismatch improves
What type of medication is milrinone?
PDE-3 inhibitor
What is a way to determine a short-RP v. long-RP tachycardia?
Draw a line at midpoint of R-R interval
P wave in first half, short RP tachycardia
P wave in second half, long RP tachycrdia
What is the differential diagnosis for a short RP tachycardia?
- Accessory pathway mediated reentrant SVT
- Typical AVNRT
- Junctional tachycardia
What are parts of the circuit in accessory-pathway mediated SVT?
Atrium
AV node (His)
Ventricle
If there are more A’s than V’s on an intracardiac ECG, what type of SVT is ruled out?
Accessory pathway-mediated re-entrant tachycardia
What type of RP relationship does EAT have?
Long RP
True or False: You can see EAT with variable AV conduction or 2:1 AV conduction
True
What is an infra-hisian block?
The block to the ventricles happens after His activation
Infra-hisian block is seen in which group of patients?
Those with AV node disease
Typical AVNRT has what pattern in intracardiac electrograms?
H-A-V
What arises when a secondary interest provides incentive for an investigator to make a determination or judgement regarding a study outcome that is informed by the incentive versus actual data?
Conflict of interest
True or False: The presence of a conflict of interest indicates the presence of wrongdoing on the part of the investiagtor
False
What is the 1st step when a conflict of interest in research is discovered?
Disclosing to the conflict of interest or review committee
Include: Compensation Equity to interest Licensing agreement or royalties Travel
Any new conflict of interest should reported within how many days of its occurrence?
Within 30 days
A conflict of interest committee has to determine if a conflict is what 2 things?
Material or related
For NIH sponsored research, what is material interest?
- Aggregate remuneration from a profit or nonprofit entity of at least $5000
- Equity in a publicly traded entity of at least $5000
- Holding equity interest in a non-publicly traded entity
- Travel reimbursed or paid for on behalf of an investigator other than by a government agency or institution of higher education
For non-NIH sponsored research, what is material interest?
- Aggregate enumeration from an entity of at least $10,000
- Ownership in a publicly traded entity of at least $10,000 equity or greater than 5%
- Holding an ownership interest or equity in a non-publicly traded entity
What questions are asked to determine if material interest is related in a question of conflict of interest?
- Are the activities of entity related to research
- Could research directly benefit from entity
- Does entity sponsor research
- Does entity own or license intellectual property studied in research
True or False: Conflict of interest always requires removal of an individual from a research study
False
What type of cardiac defects is ectopia cordis most commonly associated with?
- VSD (most common)
- ASD, conotruncal (DORV, ToF, PA), ventricular diverticulum
-Less common: AVSD, single ventricle, TGA, MV anomalies, DILV, Ebstein, HLHS
What % of newborns born with ectopia cordis have associated intracardiac anomalies?
95%
What is Pentalogy of Cantrell?
- Defect in supraumbilical abdominal wall
- Defect of lower sternum
- Deficiency of diaphragm
- Defect in diaphragmatic pericardium
- Ectopia cordis with intracardiac defect
*Some consider this syndrome to be a thoracoabdominal type of complete ectopia cordis
What are the associated non-cardiac defects in patients with ectopia cordis?
Midline defects: Cleft palate, cleft lip, absence of corpus callosum, diastasis recti, diaphragmatic hernia, omphalocele
How is ectopia cordis classified?
On the location of the heart and extent of body wall defects: Cervical Thoracic Thoracoabdominal Abdominal
What is cervical ectopia cordis?
Heart is retained in embryonic position in neck
*Almost no reported survivors
What % of infants with ectopia cordis die?
90%
Which type of ectopia cordis has a better prognosis using a staged surgical repair?
Thoracoabdominal
In complete ectopia cordis, there is a deficiency of the structures formed from what?
Somatic mesoderm
*Sternum, parietal pericardium, diaphragm, anterior abdominal wall, intracardiac defects
How does partial types of ectopia cordis present?
Sternal cleft w/o complete deficiency (may have intact pericardial layers)
What lesion is associated with abnormalities in coronary artery perfusion along with abnormalities of the coronary arteries like ostial stenosis, webs, coronary artery stenosis, or ectasia?
Supravalvar aortic stenosis
What should you consider in a patient following repair of supravalvar aortic stenosis who has ST segment elevations?
Ischemia due to inadequate coronary eprfusion
- Supravalvar ridge may cause obstruction to coronary flow and coronary arteries may be thickened with increased resistance
- Resistance to flow at STJ causes high pressure in aortic root during systole/diastole which gives better CPP
- When obstruction relived, diastolic pressure may no be high enough to get adequate flow into abnormal coronaries
- Post-op, patients may need a higher BP unless coronaries are unroofed
When would you expect to see ST segment changes due to air embolism or coronary artery vasospasm in the post-op period?
Immediate intraoperative course soon after separation from bypass
What might be needed after relief of supravalvar AS to maintain adequate coronary perfusion?
Increased systemic pressure
What is the classic arrhythmia seen in LQTS?
Torsades
What are acquired causes of prolonged QTc?
Medications, electrolyte abnormalities (hypokalemia, hypomagnesemia, hypocalcemia), anorexia, neurological abnormalities
What is the 1st line therapy for someone with hemodynamically unstable Torsades?
Defibrillation at 2-4 J/kg
What should be given for patients with shock-refractor torsades or with multiple non-sustained episdoes?
Mg Sulfate
When should amiodarone or procainamide be given for Torsades?
They shouldn’t- Both prolong QT
In cases where defibrillation and Mg don’t convert Torsades, what can be used?
Lidocaine
What should be given to a patient to prevent further episodes of Torsades?
BB
What can be given for membrane stabilization in patients with hyperkalemia?
CaCl
*Also helps with BP in hypotensive patients
What is the 1st step for hemodynamically stable SVT?
Vagal maneuvers
How do vagal maneuvers work for SVT?
- Transient increase in parasympathetic activation of the heart
- Slows sinus node
- Slow conduction in AV node and increases the AV node refractory period
- If AV node refractory period is sufficiently lengthened so it leads to 2nd degree AV block the SVT is terminated (if AVRT or AVNRT, the circuit is “broken”)
What benefit can vagal maneuvers have for rapidly conducted atrial fluuter?
Unmask flutter waves and help wit diagnosis when AV node is blocked
What are some examples of vagal maneuvers?
- Valsalva
- Modified Valsalva
- Carotid sinus massage
- Cold water immersion (“ice to face eliciting diving reflex”)
- Gagging
- Rectal stimulation
What is the modified Valsalva maneuver?
Forced expiration against a closed glottis in semi recumbent position for 15 seconds followed by supine positioning and passive leg raise
What is the standard Valsalva maneuver?
Forced expiration against a closed glottis in a semi recumbent position
Which works better for SVT termination, the modified Valsalva or standard?
Modified
Which group of patients does ice to the forehead/bridge of nose for 20-30 seconds work well in to terminate SVT?
Neonates/infants (diving reflex well preserved)
When should application of ocular pressure be used to terminate SVT?
Never- risk of retinal detachment
Why should you not apply pressure to the carotid sinus to terminate SVT in kids?
Theoretical risk of carotid artery occlusion
*Never do bilaterally or in anyone with a bruit
What vagal maneuvers are frequently effective for SVT in neonates and infants?
- Ice to forehead/bridge of nose (20-30 seconds, no ocular pressure, don’t obstruct mouth/nose)
- Rectal stimulation with a thermometer
- Gagging
What vagal maneuver is most effective for older children with SVT?
Modified Valsalva
*Adding a passive leg raise after Valsalva in a semirecumbent position
What organ is almost always affected long-term in Fontan patients?
Liver- Fontan-associated liver disease
What is one of the most serious (but rare) complications of FALD?
HCC
- May occur in absence of traditional risk factors (Hepatitis C)
- Universal screening for hepatitis and vaccines against hepatitis A and B should be considered
What do 80% of HCC in Fontan patients secrete?
Alpha-fetoprotein
What should be done for a Fontan patient with an elevated alpha-fetoprotein level?
Liver imaging- MRI or CT- to screen for hepatocellular carcinoma
FALD is associated with elevations in what lab values?
Liver markers:
- GGT (most common, 40-60%)
- Total bilirubin (25-40%)
- INR
Total bilirubin levels typically do not exceed what in Fontan patients unless there is underlying liver pathology?
3mg/dL
Osler nodes and Janeway lesion
Infective endocarditis
*Can also occur in Libman-Sacks endocarditis (SLE)
What are the skin manifestations of endocarditis?
- Splinter (periungual) hemorrhages in the nail bed
- Osler nodes (vasculitis v/ infectious microemboli from vegetation)
- Janeway lesions (microemboli from intracardiac vegetation)
How do you subdivide narrow complex tachycardia?
Based on RP relationship
How do you determine RP relationship?
- Draw a line at midpoint of R-R interval
- P-wave in 1st half = Short RP tachycardia
- P-wave in 2nd half = Long RP tachycardia
What is the differential diagnosis for a long RP tachycardia?
- Sinus tachycardia
- Atypical AVNRT
- EAT
- PJRT
What is a narrow complex re-entrant tachycardia caused by an accessory pathway with decremental conduction?
PJRT
How does the circuit flow in PJRT?
- Down the AV node
- Up the decrementally conducting accessory pathway
What causes the longer RP interval in PJRT?
- The fact that the pathway has decremental conduction
- Leads to longer conduction from the ventricle back to the atria
What is the classic ECG findings in PJRT?
Deeply negative P-waves in the inferior leads (II, III, aVF)
Describe the typical natural history of PJRT?
- Incessant tachycardia
- Usually present with signs/symptoms of heart failure due to tachycardia-induced cardiomyopathy
- Can be difficult to control with anti-arrhythmics and often requires ablation as definitive therapy
Orthodromic SVT, typical AVNRT and SVT in WPW are what type of tachycardias?
Short RP
Describe the SVT circuit in concealed accessory pathways and manifest accessory pathways
- Down AV node
- Up accessory pathway- No decremental properties in pathways, so RP is short
Describe the SVT circuit in typical AVNRT
- Down slow pathway
- Up fast pathway
- Short RP
Describe the SVT circuit in atypical AVNRT
- Down fast pathway
- Up slow pathway
- Long RP
Deeply negative P waves in the inferior leads are a classic finding in what type of tachycardia?
PJRT
How do calcium channel sensitizers (inodilators) work?
- Increase myocardial contractility by sensitizing the contractile apparatus to Ca
- Results in increased contractile force without actually increasing intracellular calcium
What are the 3 main calcium channel sensitizers?
- Levosimendan
- Pimobendan
- Omecamtiv
How does levosimendan work?
- Ca channel sensitizer (inodilator)
- Binds to troponin C which increases its affinity for Ca and stabilizes it… results in increased inotropy
- Opens ATP-sensitive K channels and other K channels causing hyperpolarization and relaxation of vascular smooth muscle…results in vasodilatory effects on arteries and veins
*Pimobendan works similarly
How does omecamtiv work?
- Ca channel sensitizer (inodilator)
- Cardiac myosin activator agent
- Facilitates actin-myosin cross-bridge formation increasing the number of myosin heads involved in force generation and stimulates myosin ATPase
What are some benefits to the calcium channel sensitizers (i.e. levosimendan) as compared to things like milrinone?
- These sensitize myocardial contractile apparatus to Ca w/o increasing intracellular Ca
- Milrinone acts via increase of CAMP
- Less arrhythmogenic (intracellular Ca homeostasis not disturbed)
- Myocardial contractility increased w/o increase in O2 consumption
- No increase in intracellular Ca (has been associated with accelerated adverse myocardial remodeling and apoptosis
True or False: Levosimendan has been studied extensively, but the use of this has not been advised or widely accepted in US due to lack of data to support clear benefits?
True
How do Ca sensitizers work?
Increase contractile force by increasing sensitivity of the myocardial contractile apparatus to Ca without increasing intracellular Ca
What genetic syndrome should you consider in a patient with CAVD and ToF?
Trisomy 21
CHD is seen in what proportion of babies with Trisomy 21?
50%
Of patients with trisomy 21 and CHD, what % have AVSD?
40%
Of patients with trisomy 21 and CHD, what % have ToF?
5%
What % of patients with AVSD have trisomy 21?
75%
What % of patients with ToF have trisomy 21?
5%
What Rastelli classification are most patients with the combination of AVSD/ToF?
C- Anterior bridging leaflet is free floating with no division and no attachments to the septum
Describe the constellation of findings in combined CAVC/ToF
- Common AV valve
- Inlet VSD
- Primum ASD
- VSD extends to outlet septum
- Conal or outlet septum deviates anteriorly
22q11.2
DiGeorge
What % of 22q11.2 patients have CHD?
75-80%
What are the most common types of CHD in 22q11.2 deletion?
ToF, IAA B, Truncus arteriosus
Other conotruncal and arch defects
True or False: AVSD is uncommon in 22q11.2 deletion
True
CHARGE syndrome is caused by a mutation in what most often?
CHD7
Coloboma, CHD, choanal atresia, growth retardation, genital abnormalities, ear abnormalities?
CHARGE
What % of patients with CHARGE syndrome have CHD?
75-85%
What are the most common CHD in CHARGE?
- Conotruncal (ToF)
- Also can have arch abnormalities, VSD, ASD, AVSD
Heterotaxy syndrome is a disorder of what?
Lateralioty
What gene mutation causes heterotaxy?
-Many associated with familial heterotaxy, but most cases have no identified gene
What type of CHD is often seen in heterotaxy?
AVSD- usually unbalanced and associated with other cardiac abnormalities
True or False: ToF isn’t commonly seen in patients with heterotaxy
True
What is the characteristic murmur of MR?
- High pitched
- S1 coincident
- Pansystolic
- Best heart at LLSB and apex and may radiate to the left axilla or back
- Diastolic rumble (if significantly increased flow across MV)
- Prominent P2 or narrowly split/single S2 (if MR severe and there is pulmonary HTN)
- Mid-systolic click (MVP)
What might seen on ECG with severe mitral regurgitation or if there is associated mitral stenosis with regurgitation?
LAE
Globally, what is the most common cause of MR?
Rheumatic mitral valve disease (infrequent in US)
What mitral valve changes are associated with acute rheumatic fever?
- Chordal elongation
- MVP
- Annular dilation
What mitral valve changes is chronic rheumatic fever associated with?
- Chordal shortening
- Incomplete valve coaptation
- Varying amounts of MS
What is the definition of MVP by echo?
Systolic protrusion of the body of the MV leaflet beyond the annular plane (usually seen in PSLA views)
What is the most common underlying cause of MR that requires surgical repair in pediatrics?
Congenital MV anomalies
What areas of the MV can have anomalies?
- Leaflets
- Tension apparatus
- Papillary muscles
- Any combination
How is an isolated cleft in the anterior leaflet of the mitral valve regognized?
Division of the anterior leaflet such that the normally bifoliate or “fish-mouth” mitral valve apparatus appears trifoliate or triangular
In an isolated cleft of the mitral valve, where is the cleft directed towards?
Aortic outflow
An isolated cleft of the mitral valve in AVSD is directed towards what?
Ventricular septum
What causes the MR in cleft mitral valve?
The space between the cleft components produces the substrate for regurgitation
How is a cleft mitral valve repaired?
Closing it with sutures
How would ALCAPA lead to mitral regurgitation?
Papillary muscle dysfunction from the ischemic insult
What would you see on echo with an ischemic insult of the papillary muscles?
Echobright fibrotic changes in the papillary muscles and LV endocardium (+/- MVP)
Infant with irritability, poor feeding, CHF, abnormal ECG and MR on echo?
Think about ALCAPA
What might cause mitral valve perforation or chordal rupture?
Endocarditis
S1 coincident, high-pitched, holosystolic, blowing murmur at or near the apex?
MR
What are the 2 categories of metabolic acidosis?
Anion gap
Non-anion gap
How is the anion gap calculated?
Na - (Cl + Co2)
What is a normal anion gap?
<12mEq/L (some day up to 16)
What does the anion gap represent?
Difference between physiologic cations and anions found in serum, but not measured in standard chemistries
What does an elevated anion gap indicate?
Presence of non-physiologic anions that produce a metabolic acidosis
What are the causes of a anion gap metabolic acidosis?
MUDPILES: Methanol, uremia, DKA, paraldehyde, isoniazid, lactic acidosis, ethanol/ethylene glycol, salicylates
An anion gap acidosis in someone with heart failure should raise concern for what?
Lactic acidosis
What is the primary cause of lactic acidosis in the heart failure population?
Tissue hypoperfusion from decreased O2 delivery related to poor heart function
Metabolic acidosis with a normal anion gap is typically caused by what?
- Loss of serum bicarb (diarrhea, RTA)
- Excess chloride (often iatrogenic)
What adjustment can be made to TPN if there is a non-gap metabolic acidosis and normal lactate levels?
Decrease Cl in TPN and use a buffer like NaAcetate
How do loop diuretics affect chloride?
Cause chloride loss from distal loop of Henle
Why does NaBicarb have negligible effect on hyperchloremic metabolic acidosis?
-Elevates Na level and causes parallel elevation in Cl level
Hyperchloremic metabolic acidosis is often due to what?
Iatrogenic (fluid resuscitation, TPN)
What flow abnormalities are seen on fetal echo in HLHS?
- L-R atrial level shunting through PFO
- Retrograde flow into ascending aorta supplied by ductus arteriosus
When the disruption of normal development in HLHS occurs early in gestation, it is typically caused by what?
Posterior/leftward deviation of the superior edge of the septum primum resulting in abnormal attachments to the LA wall
- Results in development of a intact atrial septum or a small foramen ovale that may close over time and lead to restricted atrial shunting
- Fetal LV is primarily filled by flow through foramen and depends on that filling for normal formation… this flow abnormality leads to impairment of LV development and development of associated structures
Describe the flow of blood in the fetal heart with HLHS
- Returns from pulmonary veins and enters LA
- Crosses small foramen ovale through RA
- Goes into RV and PA
- Majority of flow through ductus arteriosus into descending aorta
*May see retrograde flow into ascending aorta- May be only supply to cerebral and myocardial circulations, depends on severity of left heart obstruction
When the disruption of normal development in HLHS occurs late in gestation, it is typically caused by what?
Intrinsic abnormalities in formation of left heart valves (especially aortic valve)
Where is the aortic valve derived from?
Endocardial cushions in the outflow tract of the primitive looped heart tube
How does significant obstruction to flow across the aortic valve in fetal life result in HLHS?
- Causes shear stresses in developing ventricle
- Leads to abnormal growth and remodeling- LV cavity is diminished and walls become abnormally thick
- Changes eventually result in EFE and state of restrictive cardiomyopathy
- LVEDP and LA pressures rise
- Decreased shunting through the foramen ovale and less flow into in left heart
- Left heart underdevelopment worsens
Pulmonary venous abnormalities are associated with abnormalities in LV growth and development at what stage of gestation?
Later stages
- Early gestation, limits flow through pulmonary veins
- As pulmonary circulation increases in 3rd trimester and foramen ovale becomes relatively restrictive, LV preload becomes more dependent on pulmonary venous return
When HLHS is evident early in gestation with profound underdevelopment of the LV, what is the most likely cause?
Abnormal flow into the left heart caused by restriction at the atrial septum which is caused when the superior edge of the septum primum is deviated posteriorly and leftward forming abnormal attachmens in the LA
When HLHS becomes evident later in gestation after a normal-sized LV had been identified previously, what is the likely cause?
- Primary abnormalities in the AoV
- Primary abnormalities in the pulmonary veins
What lab value needs to be interpreted in the context of SpO2?
Hgb- Someone with a saturation in the 80s, should have polycythemia
-A “normal” Hgb for someone life this would be anemic
What should be given to patients with Eisenmenger physiology with evidence of iron deficiency?
Ferrous sulfate
What might be a cause of increased dyspnea on exertion for someone with Eisenmenger physiology?
Anemia
How often should Eisenmenger patients be screened for anemia?
At least yearly
*Also get a menstrual history in women to assess for menorrhagia as a possible cause
Pulmonary hypertension therapy in patients with Eisenmenger syndrome serves what purpose?
- Improved quality of life
- Improved 6-minute walk test
*NO mortality benefit has been shown
What type of drug is bosentan?
Endothelin-receptor antagonist
True or False: All Einsenmenger patients should be taking warfarin
False- There is a risk of pulmonary hemorrhage
*Most patients not prescribed warfarin unless there is a specific indication
What is the most common presenting symptom in acute pericarditis?
Chest pain
Describe the pain in pericarditis?
- Sharp precordial pain
- Worsens on inspiration
- Relieved by sitting up and leaning forward (tripod)
What exam finding is highly specific for the diagnosis of acute pericarditis?
Pericardial friction rub
Describe a pericardial friction rub
Triphasic, superficial, scratchy sound best heard with diaphragm of stethoscope at LSB in leaning forward position
True or False: Absence of a friction rub rules out pericarditis?
False- large effusions may be less likely to have a rub
Describe tamponade physiology?
- Inspiration: Venous return to right side of heart increases because of reduced intrathoracic pressure. In tamponade, increased venous return to right side doesn’t allow RV free wall to expand because of increased pericardial pressure from pericardial fluid
- Increased RV volume causes IVS to bulge to left
- Septal position and underfilling of LV reduce its output (due to ventricular interdependence)
- Decreased LV SV seen as drop in SBP >10mmHg during inspiration (“pulsus paradoxus”)
Hypotension, elevated JVP with jugular venous distension, distant heart sounds
-Beck’s triad
This + pulsus paradoxus signal need for emergent intervention in patient with pericardial effusion
What are the echo findings of tamponade?
-Late diastolic RA inversion
-Early diastolic RV collapse
(*Both occur b/c intrapericardial pressure > RA and RV diastolic pressure)
-Respiratory variation in transvalvular flow >25% across MV or >40% across tricuspid
-IVC dilation
-Swinging motion of heart
What is next step when tamponade physiology is identified?
Pericardiocentesis
When are pericardial windows used?
Recurrent symptomatic effusions that can’t be controlled with medical therapy
What causes pericarditis?
-Inflammation of pericardium
- Infectious (Viral, bacteria, fungal, rickettsial)
- Inflammatory
- Metabolic
- Drug-related
- Radiation-related
- Traumatic
- Post-op
- Idiopathic
*Direct management towards underlying etiology if cause known
What is the mainstay of therapy for acute viral pericarditis?
NSAIDs
*Recent studies show NSAIDs + Colchicine decrease symptoms and recurrences and is better tolerated than NSAIDs alone
When are steroids used for pericarditis?
- Patients with connective-tissue disorders
- Immune mediated pericarditis
- Patients who don’t respond to NSAID’s/colchicine
- Patients whom NSAIDs are contrinadicated
*Avoid in most other cases due to risk of recurrence and contraindication with many types of infections
What is the treatment for cardiac tamponade?
Drainage of pericardial fluid (especially unstable patients
What is indicative of hemodynamic compromise in a pericardial effusion?
- Beck’s triad: Hypotension, elevated JVP with JVD, distant heart sounds
- Pulsus paradoxus
What is associated with IAA A?
AP window
What is the 2nd most common type of IAA?
A
What causes IAA Type A?
Involution of both dorsal aorta- Creates an interruption in the arch distal to the origin of the left subclavian artery
Describe the findings in IAA A after birth?
- Immediate: May be asymptomatic, but SpO2 will be decreased in the lower extremities
- As PDA closes, pulses diminish and SpO2 decreases… PDA is only source of blood flow to lower body so closure will lead to shock/death
What is an AP window?
Communication between AscAo and MPA
What % of cases of AP window are associated with other CHD?
50%- IAA most common
Describe the physiology of AP window
- Continuous L-R shunting
- PA pressure remains elevated due to unrestrictive communication between Ao and PA
- As PVR drops, shunt increases causing pulmonary overcirculation and CHF
Describe the PE in AP window?
CHF signs/symptoms, systolic or continuous murmur, widened pulse pressure, bounding pulses
True or False: Bicuspid AoV is commonly seen with IAA A
True
Which type of IAA is a VSD more common in, A or B?
B (but can be seen in either)
Where is the interruption in IAA tpye B?
Between left common carotid artery and left subclavian artery
Where is the interruption in IAA A?
Distal to the origin of the left subclavian artery
LQT1 and LQT2 are caused by what type of gene mutation?
Loss-of-function mutation in a delayed rectifier potassium channel (Iks or Ikr)
-2 other genes that cause LQTS cause loss of function of the inward rectifier K channel (IK1)
How do the loss-of-function mutation in delayed recitifier K channels and loss-of-function mutation of the inward rectifier K channel cause as long QTc interval?
- K efflux through the 2 channels during phase 2/3 of the action potential lead to repolarization
- Loss of function in these would delay repolarization causing a prolonged action potential and QTc interval on ECG
What are pore-containing transmembrane proteins that allow for movement of charged particles (typically cations) across the lipophilic cell membrane?
Ion channels
What do ion channels typically consist of?
1+ pore-forming subunits (alpha subunit)
Several secondary subunits (B and y)
What do the secondary subunits that are part of an ion channel do?
Alter expression of gene, augment channel activity, or assist in gating (opening/closing ion channels)
What 3 things can trigger gating of an ion channeL?
- Voltage
- Attachment of ligands
- Stretch
What creates the action potential?
Open and closing of ion channels
What is phase 4 of the action potential?
Resting potential
*Most myocytes remain in this phase until acted on by the depolarization of an adjacent cell via gap junctions
What is the resting membrane potential for most myocyes?
-90mV
What maintains the resting membrane potential for most myocytes?
Adenosine triphosphate using ion pumps (Na/K exchanger, Na/Ca exchanger)
Which types of cardiac cells have different action potentials compared to typical myocytes?
Cells in the sinus node and AV node
How is Phase 4 of the action potential different in the cells in the sinus node/AV node compared to typical myocytes?
- Many ion channels contribute to a gradual phase 4 depolarization (Ikr, L and T-type Ca channels)
- These cells uniquely express hyperpolarization-activated cyclic nucleotide-gated (HCN) channels that allow influx of Na and K (funny current) and are activated by the hyperpolarization seen at the start of phase 4 leading to gradual depolarization and automaticity
What happens after Phase 4 of the action potnetial?
Phase 0
What is Phase 0 in the action potential?
Rapid depolarization
What occurs in Phase 0?
Voltage dependent conformation change in Na channel allows Na to rapidly enter the cell
What phase of the action potential is a transient rapid partial repolarization?
Phase 1
What causes Phase 1 of the action potential?
K efflux via transient outward current (Ito)
*Most Na channels closed at this point
Which phase of the action potential is the plateau phase?
2
What happens during Phase 2 of the action potential?
Balance of outward (K+, via related rectifier K channels) repolarizing and inward (Ca2+, via L-type Ca channels) depolarizing
What happens during Phase 3 of the action potential?
Rapid depolarization- L-type Ca channels close and delayed rectifier K channels remain open causing the cell to repolarize
A loss of function mutation in the delayed rectifier K channel would do what?
Hinder repolarization
Causes prolonged QT interval
Loss of function mutations in the delayed rectifier K channel cause what?
LQTS 1 and LQTS2
Gain of function mutations in the delayed rectifier K channel would cause what?
Shortened QTc interval (SQT1 and SQT2)
A loss of function mutation in the hyperpolarization-activated cyclic nucleotide-gated channels causes what?
Sinus bradycardia
A loss of function mutation in the L-type Ca channels would have what effect on QTc?
Shorten it
- Allows K to be unopposed during phase 2
- SQT5 and SQT6
A gain of function mutation in the L-type Ca channel causes what?
Prolonged QTc
-LQT8, Timothy syndrome
A loss of function mutation in the Na channels would cause what?
- Slow conduction velocity (related to upstroke in phase 0 of AP)
- Brugada syndrome, sick sinus syndrome, conduction disease
*Small number of Na channels remain open throughout repolarization phase of the AP (Late Na current which is depolarizing)… so loss of function mutation in Na channel might shorten QTc interval
What does a gain of function mutation in the Na channel do to the QTc?
Prolongs (LQT3)
Rapid depolarization via influx of Na through voltage gated Na channels?
Phase 0
Transient rapid repolarization via efflux of K via transient outward K channels?
Phase 1
Plateau phase- balance of Ca influx (L-type Ca channels) and K efflux (delayed rectifier K channels)?
Phase 2
Rapid depolarization (Ca channels close and K channels remain open)
Phase 3
Resting potential
Phase 4
What is the channel function of the delayed (IKs/IKr) or inward (IK1) rectifier K channel?
Repolarization
Loss of function mutation in delayed (IKs/IKr) or inward (IK1) rectifier K channel?
Long QT
Gain of function mutation in delayed (IKs/IKr) or inward (IK1) rectifier K channel?
Short QT
Function of L-type Ca channel?
Maintenance of depolarized state in phase 2
Loss of function mutation in L-type Ca channel?
Short QT
Gain of function mutation in L-type Ca channeL?
Long QT
Role of hyperpolarization activated cyclic nucleotide-gated channel (HCN)?
Phase 4 depolarization
Loss of function mutation in HCN channel?
Sinus bradycardia
Gain of function mutation in HCN channel?
Atrial fibrillation
Function of sodium channel (SCN5A)?
Phase 0 depolarization, late (phase 2-3) maintenance of depolarization
Loss of function mutation in SCN5A?
Conduction velocity slowing- Brugada, sinus node dysfunction, conduction system disease, short QT
Gain of function mutation in SCN5A?
Long QT
Na channel opening leads towhat?
Rapid repolarization
Loss of function in Na channels (SCN5A) leads to what?
Brugada
K channel opening leads to what?
Repolarization
Loss of function in K channels can lead to what?
Increased refractoriness and long QT
L-type Ca opening leads to what?
Inward current opposing repolarization (as well as regulating excitation-contraction coupling)
Gain of function in L-type Ca channels leads to what?
Long QT syndrome (Timothy syndrome)
What are the 2 potential embryological processes which could lead to isolated PAPVR?
- Malposition of the septum primum
2. Anomalous isolated PAPVR
How can malposition of the atrial septum primum lead to isolated PAPVR?
- Septum secundum is absent (usually with visceral heterotaxy with polysplenia)
- Septum primum may then be displaced towards anatomic LA
- Displacement of upper border of septum primum results in incorporation of half to all of the pulmonary veins into the RA
*In many cases, displaced septum primum won’t reach posterior wall of LA resulting in small superior interatrial communication… displaced and mobile upper border of septum primum helps with diagnosis
What are the 2 essential anatomic elements that make a malpositioned septum primum towards the LA and isolated PAPVR possible?
- Absence of septum secundum
- Well- developed septum primum
*When septum primum fuses with posterior LA wall, no interatrial communication
What location of the pulmonary veins supports that isolated PAPVR is due to malpositioned septum primum?
The pulmonary veins are normally connected to the atrial wall- Located between the right and left SVCs (if 2 SVCs present)
What is a deficiency of the common wall between the right SVC and right upper pulmonary vein or the wall between the right atrium and right upper/lower pulmonary veins?
Superior sinus venosus defects
- SVC Type: Unroofing of RUPV and branches to right SVC
- RA Type: Unroofing of RUPV/RLPV to RA
What is it called when there is a deficiency between the RLPV and RA or at IVC-RA junction?
Inferior sinus venosus defect (uncommon)
What are the 3 criteria for a inferior sinus venosus defect?
- Posterior or inferior defect confluent with the posterior wall of the atria with no posterior or inferior rim
- Confluence of the defect with the R pulmonary veins or IVC-RA junction
- Presence of a well-developed septum primum covering the fossa ovale without fenestrations
What is a variant of PAPVR in which part or all of the right lung is drained by right pulmonary veins that connect anomalously to the IVC?
Scimitar
*Anomalous draining vein looks like a scimitar (Turkish sword) on CXR or MRI
What are the effects on the affected lung in Scimitar?
- Hypoplastic
- Sequestration
- AP collaterals
Short PR, delta wave, wide QRS?
WPW
What agents are contraindicated in WPW?
AV nodal blocking agents- Digoxin, CCB (verapamil)
Why are AV nodal blocking agents contraindicated in WPW?
They can enhance AP conduction and increase risk of sudden death (A-fib that conducts rapidly down AP causes v-fib)
What antiarrhythmic class is sotalol?
Class III
-Some weak B-blocker properties
How do class III antiarrhythmics work?
- Block K channels during phase 3 of AP and prolong repolarization
- Increase in ERP of cells leads to decreased likelihood that early activation will lead to a new action potential (prevents pre-entrant arrhythmias)
What changes on ECG will you see with a class III antiarrhythmic like sotalol?
QTc prolongation
What causes QTc prolongation seen with class III antiarrhythmics?
- Prolonged action potential
- Increased refractory period
What patients are class III antiarrhythmics contraindicated in?
Long QT
What diagnosis needs to be considered in patients with unexplained pulmonary hypertension?
Pulmonary vein stenosis
What is the most commonly associated lesion with pulmonary vein stenosis?
Left-sided obstructive lesions
*Others including AVSD are also seen
What 2 cath pressures would show pulmonary vein stenosis?
Elevated capillary wedge pressure on one side with normal LA pressure
What are the 4 major categories of VSDs?
- Perimembranous (conoventricular)
- Inlet (AVC)
- Muscular
- Subarterial (Supracristal, conoseptal, outlet)
What type of incision is used to repair a subarterial (supracristal, conoseptal or outlet) VSD?
Supravalvar pulmonary incision
-Incision into the pulmonary artery (Transarterial) just above the pulmonary valve
What type of incision is used to repair an inlet, perimembranous or mid-muscular VSD?
Right atrial incision
What type of incision is used to repair a muscular VSD below the moderator band and anterior to the septal band?
Anterior right ventriculotomy
What type of incision is used to repair a posterior apical muscular VSD?
Apical left ventriculotomy
In the PSSA view, what “clock position” is a subarterial (Supracristal, conoseptal or outlet) VSD located?
12-3
What should you consider with a SEM in a patient who has undergone a device closure for a PDA?
LPA Stenosis or Descending Ao stenosis
- Devices often extend into PA
- Proximity of pulmonary arterial end of PDA to LPA origin may result in portion of the device partially occluding the LPA origin
What types of patients are more likely to have LPA stenosis following device closure of a PDA?
Small patients with large PDAs
True or False: The LPA stenosis seen following device closure of a PDA is usually mild and unlikely to be significant enough to warrant intervention?
True- spontaneous improvement over time has been noted
True or False: Residual shunts after device placement for PDA closure are rare?
True- Reported in the 2-3% range
What should you expect when a pacemaker impedance drops suddenly?
Insulation breach- Current has developed an additional pathway (out to the body)
How does an insulation breach with a pacemaker present?
- No symptoms (increased battery drain)
- Oversensing myopotentials- wrongly inhibits the pacemaker
- Loss of capture
- Stimulation of nearby musculature (rare)
What is the most common cause of insulation breach in a transvenous pacemaker?
Subclavian crush syndrome
What causes subclavian crush syndrome leading to an insulation breach in a transvenous pacemaker?
Mechanical damage to the pacing lead as it passes between the first rib an clavicle
*Can also cause lead fracture
What change would you expect to see with a pacemaker lead fracture?
The impedance is markedly increased
Which approach for transvenous pacemaker placement is most likely to prevent an insulation breach or lead fracture?
Axillary (over subclavian)
- Decreased incidence of pneumothorax with axillary approach
- Lead is better protected from subclavian crush syndrom
Placement of an atrial pacing lead in the RAA can contribute to what?
Far-field R wave oversensing in the atrial lead
Decreased pacemaker lead impedance should make you think of what?
Insulation breach
Increased pacemaker lead impedance should make you think of what?
Lead fracture
Which approach (axillary or subclavian) to the venotomy in pacemaker placement decreases the risk of pneumothorax and lead injury caused by subclavian crush?
Axillary
True or False: TAPVC and CoA commonly occur together?
False- TAPVR is usually an isolated defect
What finding regarding the aortic arch is common in a patient with obstructed TAPVC?
“Small” arch without true CoA
What clinical circumstance might underestimate a CoA gradient?
Decreased ventricular function
What is the % mortality in TAPVC repair?
5%
What % of patients with Noonan have CHD?
> 80%
What are the most common forms of CHD in Noonan?
- PV stenosis (>50% of patients)
- ASD
- HCM (can be present as early as the neonatal period)
Approximately 1/2 of the cases of Noonan syndrome are associated with what gene mutation?
PTPN11
What gene encodes tyrosine phosphatase SHP-2 (component of several signal transduction pathways involved in embryonic development that modulate cell division, differentiation and migration)?
PTPN11 (Noonan)
List some of the gene mutations associated with Noonan syndrome?
PTPN11 SOS1 RAF1 KRAS NRAS
What gene mutation is most frequently associated with Noonan and HCM?
RAF1
What causes the neonatal edema which can be seen in Noonan?
Abnormalities of the lymphatic system including diffuse lymphedema
*Hydrops fetalis is uncommon
How is Noonan often inherited?
AD
The familial presentation of Noonan syndrome is more often seen with which gene mutation?
PTPN11
JAG1 mutation?
Alagille
How is Alagille inherited?
AD, but with reduced penetrance and variable expression
What forms of CHD are seen in Alagille?
- Peripheral pulmonary artery stenosis
- Pulmonary valve stenosis
What CHD is commonly seen in Turner syndrome?
Left-sided heart obstructive lesions: CoA, Bicuspid AoV
What is different about the lymphedema seen in Turner syndrome v. Noonan syndrome?
- Turner: Isolated puffiness or swelling of the hands and/or feet + cystic hygroma
- Noonan: Diffuse total body edema
45 XO?
Turner
What are the top 2 most prevalent syndromic causes of CHD?
Down
Noonan
True or False: HCM and isolated semilunar valve abnormalities are rarely associated with Down syndrome?
True
What is the most common CHD seen in Down syndrome?
Complete AVCD
*Then isolated VSD
True or False: It is not common for newborns with Down syndrome to have lymphedema or diffuse total body edema?
True- increased nuchal thickening is common, but not others
What direction is normal ductal flow in fetal life?
R-L from PA to descending Ao (most of RV outflow bypasses the pulmonary circulation)
What is a sign on fetal echo for ductal-dependent pulmonary blood flow?
Retrograde flow from the ductus arteriosus (left to right from Ao to Pulmonary artery)
For a patient with DORV + PS and fetal echo with ductal flow from Ao to Pulmonary artery, what needs done following birth?
- PGE
- Then ductal stent or BTT shunt
- Then Full intracardiac repair (hopefully biventricular)
When is a balloon pulmonary valvuloplasty recommended?
If obstruction is primarily valvar… less effective with associated annular hypoplasia and valve dysplasia, also won’t address any infundibular obstruction
For a patient with DORV + PS and fetal echo with ductal flow from Pulmonary artery to Ao, what needs done following birth?
Possibly nothing… if circulation balanced, may be able to do elective surgical repair few months after birth
When is O2 or a pulmonary vasodilator helpful to promote increased pulmonary blood flow?
- With functional PA (not anatomic obstruction)
- Occurs when valve is patent, but no forward flow because RV can’t generate pressure differential… this can be seen in Ebstein when PVR remains high
Retrograde flow in the ductus arteriosus in fetal life suggests what?
Post-natal ductal-dependent PBF
What are the options with critical PS after birth?
- Relieve obstruction
- Alternate source of PBF
- Both
How do most children with an isolated CAF present?
Asymptomatic murmur
What is the most common cause of symptoms due to a CAF?
Large L-R shunt causing DOE or HF symptoms (v. coronary steal)
List some presentations of CAF
- Asymptomatic
- Murmur
- HF symptoms- DOE, poor growth, CHF
- Chest pain (ischemia due to coronary steal)
- Arrhythmias (usually later in life and due to ischemia/infarction)
*MI is very rare
What is an abnormal vascular communication between a coronary artery and a cardiac chamber or blood vessel?
CAF
*Fistula bypasses the myocardial capillary bed
True or False: CAF is usually a solitary finding?
True
*Very rare, only accounts for 0.4% of CHD
What causes most CAF?
- Congenital (possibly from persistence of a sinusoidal coronary arterial connection)
- Following cardiac surgery
- Following endomyocardial biopsy
Where do most CAF exit to?
Right heart (90%): RA or RV
- Can enter vena cava, CS, or PA
- Less common is LA or LV
Describe the murmur commonly seen with CAF
Continuous (due to pressure gradient maintained throughout systole and diastole)
When is a continuous murmur accentuated in CAF v. PDA?
CAF- Accentuated in diastole
PDA- Accentuated in systole
What 2 things cause symptoms associated with a coronary artery fistula?
- Significant L-R shunt
- Coronary steal
What happens that can result in thrombus formation in CAF?
Coronary dilation, ectasia and aneurysm (with larger lesions)
True or False: Adults are much more likely to have complications due to CAF as compared to children?
True: More than 1/2 of adults have complications compared to 19% or less in kids
*CHF, MI, rupture, infective endocarditis, death
True or False: A small CAF may closure spontaneously?
True
What should be done for a small CAF?
Observation
What should be done for a large CAF?
-Depends on size, symptoms and course of fistula
What is a potential complication following a CAF closure?
Thrombus propagation in the coronary artery feeding the fistula
*Results in myocardial ischemia
What types of VSDs are associated with aortic cusp prolapse and resultant AI?
Membranous and outlet
Which type of VSD is most likely to result in AI due to aortic cusp prolapse?
Outlet (membranous can also do this too)
*Outlet are 5x more likely to lead to aortic prolapse and AI (50-75% of cases)
What are other names for outlet VSDs?
- Conal septal
- Subarterial
- Infundibular
- Doubly committed juxta-arterial
- Subpulmoanry
- Supracristal
Where is an outlet VSD located?
In the muscular septum that supports the PV
*Can extend to the membranous septum
What is the involvement of the aortic valve with an outlet VSD?
The right coronary cusp forms the roof of the VSD and can prolapse into the VSD
What feature of outlet VSD flow can lead to prolapse of the aortic valve?
Venturi effect
What result from prolapse of the aortic valve into an outlet VSD/
AI
True or False: Outlet VSDs are unlikely to close spontaneously?
True- but the prolapse of the right coronary cusp can effectively close the defect
What are other names for a membranous VSD?
- Perimembranous
- Paramembranous
- Conoventricular
- Infracristal
- Subaortic
Where are membranous VSDs?
- Membranous septum
- Sit behind the septal leaflet of the TV and under the right/non-coronary cusps of the aortic valve
What tissue may close a perimembranous VSD?
Accessory tricuspid valve tissue
True or False: You can see aortic cusp prolapse and AI with a perimembranous VSD?
True- Rate is lower than outlet VSDs (10-15%)
What is the 2nd most common type of VSD?
Trabecular or muscular
What defines a muscular VSD?
They have all muscular rims
What is the natural history of a small muscular VSD?
Spontaneous closure
Where is an inlet or AV-canal type VSD?
Within the muscular septum opening into the inlet region of the AV valves
*May be completely contained within muscular septum or also include perimembranous region
What can happen when there is an inlet VSD with malalignment of the ventricular septum?
Straddling of the AV valves
What is a major factor that results in prolapse of the aortic cusp in the setting of a membranous or outlet VSD?
Venturi effect
The increase in PBF after birth is accomplished by what?
Decrease in PVR
What causes the decrease in PVR after birth?
- Onset of ventilation
- Increased O2 tension
- Vasodilation due to NO and prostacyclin from vascular endothelium
What happens when the PVR does not fall normally after birth?
PPHN
What causes PPHN?
Not well understood…
- Rare familial
- Can complicate lung disease in Down, alveolar capillary dysplasia, genetic abnormalities of surfactant function, lung hypoplasia
- Perinatal conditions: Depression, GBS
What are the clinical signs of PPHN?
- Hypoxia
- Differential upper/lower extremity saturations
*Not specific to PPHN and overlap with other CHD
What is needed to diagnose PPHN?
ECHO
What is the connection of the papillary muscles to the mitral leaflets (either directly or via short chordae which are thickened)?
Anomalous mitral arcade or hammock mitral valve
*Abnormal excursion of leaflets which can cause stenosis and insufficiency
How does isolated congenital mitral valve stenosis present?
Pulmonary HTN in newborn
What is TAPVC characterized by on echo?
Obligatory R-L shunt at PFO (v. bidirectional)
What do you have to rule out via echo for a neonate with pulmonary HTN?
TAPVC
How does a vein of Galen malformation present?
High output cardiac failure
What exam finding is consistent with a vein of Galen malformation?
Audible bruit at anterior fontanelle
What are echo findings seen with vein of Galen malformation?
Enlarged innominate vein, SVC, right-sided heart chambers, pulmonary trunk, proximal aorta and proximal aorta branches
True or False: Pulmonary HTN of often found in vein of Galen malformation and can cause R-L shunting at PDA?
True
What should you consider with severe pulmonary HTN, right-sided heart dilation and retrograde flow in the ascending or descending aorta?
Vein of Galen malformation
What is a vein of Galen malformation?
Cerebral AVM with connections between any of several arteries and the vein of Glaen
When does a vein of Galen malformation present?
Any time, but more severe disease presents earlier
What are common findings in vein of Galen malformation?
Respiratory distress, cyanosis, decreased breath sounds (due to cardiomegaly) and cranial bruit
*Typical of CHF
What is the pathphysiology in vein of Galen malformation?
-Large AVM: Wide pulse pressure Right heart volume overload Depressed RV function LV function preserved or hyperdynamic
What does vein of Galen malformation presentation mimic?
PPHN
What is different about the CXR in vein of Galen malformation and PPHN?
Vein of Galen: Increased interstitial pulmonary edema
PPHN: Oligemic
What other CHD can a vein of Galen malformation be associated with?
- Sinus venosus ASD
- CoA
What are common echo findings in vein of Galen malformation?
- Dilated SVC
- Right heart enlargement
- Decreased RV function
- Dilated main and proximal branch PAs
- Dilation of head/neck vessels (especially carotid)
- Diastolic runoff into head vessels on Doppler
- Reversal of flow in descending aorta
- R-L flow in PDA
How is a vein of Galen malformation typically identified?
Cranial US and then confirmed by CT with contrast
What is the primary treatment for a vein of Galen malformation?
- Surgical or interventional closure
* Symptomatic treatment of CHF in meantime
What are the outcomes for patients with a vein of Galen malformation related to?
- Presence of absence of other congenital anomalies
- Size/amenability to surgery/interventional therapy
What needs to be considered in a newborn with high-output CHF?
Vein of Galen malformation
What are the general goals when choosing a vasoactive agent for a neonate with low cardiac output?
- Increase CO
- Increase O2 delivery
- Don’t increase myocardial work/O2 demand
- Preserve or decrease SVR
How does milrinone work?
Phosphodiesterase inhibitor
What does milrinone due to inotropy?
Increases it
What does milrinone due to SVR?
Decreases it
What does milrinone due to PVR?
Decreases it
What does milrinone due to renal vascular resistance?
Decreases it
How does milrinone increase inotropy?
- Inhibits phosphodiesterase III
- Increases cAMP in cardiac myocytes- alters Ca influx and improves systolic and diastolic function
What effect does milrinone have on HR?
Variable:
- Reflex tachycardia due to systemic vasodilation and associated hypotension
- May be offset by improved CO with improved BP and HR may decrease
Epinephrine and dopamine have predominantly what effect?
Alpha-adrenergic:
- Increased inotropy
- Increased HR
- Increased SVR
- Increased PVR
- Increased renal vascular resistance
What is the effect of epinephrine at a low dose similar to?
Milrinone effects
During CPR, what is the vasopressor of choice?
Epinephrine
What effect on vascular resistance does dopamine have at higher doses?
Increases vascular resistance (activates more alpha1-adrenergic receptors)
What does norepinephrine do to inotropy, HR, SVR, PVR and renal vascular resistnace?
- Increased: Inotropy, HR, SVR, PVR
- Decreased: Renal vascular resistance
Why is milrinone such a favorable agent in post-op low cardiac output?
Dual effects of increased contractility and decreased SVR
Why might D-TGA with intact ventricular septum be missed on fetal echo?
No VSD to trigger an abnormality and outflow tracks can be hard to image
What are some classic exam findings with D-TGA-IVS?
- Single loud S2
- Cyanosis
- No murmur
- Normal pulses
What causes the single S2 seen in D-TGA-IVS?
More AP orientation of the semi-lunar valves
What does the critical congenital heart disease screen serve to indentify?
- HLHS
- PA-IVS
- TGA
- Truncus
- Tricuspid atresia
- ToF
- TAPVC
True or False: There is a false-negative incidence with CCHD screen
True- any infant that passes initial screen, but then becomes cyanotic needs a full workup
In single ventricle patients s/p Norwood/BTT the SpO2 in the PAs is equal to what?
Aortic saturation
What equation is used to calculate blood flow across the pulmonary and systemic circulation?
Fick’s equation
Flow across the aortic and pulmonary tracks is inversely proportional to what?
Saturation differences
What is the equation for Qp:Qs?
(Aortic sat - Mixed venous sat)/(PV sat - PA Sat)
What is the equation for oxygen contant?
SpO2 * Hgb * 1.36 * 10 + 0.003 (PaO2)
*The dissolved O2 (0.003 * PaO2) in blood in patients in room air is clinically insignificant and not included in CO equations
What is the equation for CO via Fick equation?
CO = VO2 (mL/min) / ((Systemic arterial sat- Mixed venous sat) * Hgb * 1.36 * 10)
What is the equation for CI?
Same as CO, but index VO2 to BSA
CO = VO2(mL/min/m2) / ((Systemic arterial sat- Mixed venous sat) * Hgb * 1.36 8 10)
What is the equation for Qs?
CO = VO2(mL/min/m2) / ((Systemic arterial sat- Mixed venous sat) * Hgb * 1.36 8 10)
What is the equation for Qp?
CO = VO2(mL/min/m2) / ((PV sat - PA sat) * Hgb * 1.36 8 10)
How do you calculate a shunt volume?
The difference in total flow between Qp and Qs
What does the ratio of pulmonary to systemic blood flow provide?
Estimate of volume loads on various cardiac chambers
What is arrhythmia-induced cardiomyopathy?
Depressed ventricular function mediated by an arrhythmia
How is arrhythmia induced cardiomyopathy diagnosed?
Control of the potentially causative arrhythmia with subsequent improvement in ventricular function
If another etiology was found to result in depressed ventricular function in the setting of a high ventricular ectopy burden, is treatment of the ventricular ectopy warranted?
Yes- it may exacerbate worsened function
True or False: Medical management of heart failure is still indicated in the setting of an arrhythmia induced cardiomyopathy even after control of the arrhythmia?
True- Something like an ACEi
What causes most cases of arrhythmia induced cardiomyopathy in adults, neonates and older children?
Adults: A-fib
Neonates: Unrecognized SVT
Older children: EAT
What leads to the development of arrhythmia induced cardiomyopathy?
Chronically elevated HR
Ventricular desynchrony
Why do atrial arrhythmias more frequently lead to arrhythmic induced cardiomyopathy?
- More common
- Often lead to unrecognized chronic elevations in HR
True or False: Simple PVCs can lead to arrhythmia induced cardiomyopathy when there is a high burden of PVCs?
True
*Rare even with high burdens of PVCs… studies suggest that at least 10,000 PVCs/24 hours are needed to lead to cardiomyopathy
What is the cellular mechanism for arrhythmia induced cardiomyopathy?
Similar to other causes of LV dysfunction: Sympathetic system activation, neurohormonal activation, remodeling of the extracellular matrix and cell structures, defects in Ca handling
*Why HF meds like ACEi are needed even with control of the arrhythmia
What is the mainstay of treatment of arrhythmia induced cardiomyopathy?
Control arrhythmia: Anti-arrhythmics or ablation
Ablation often most effective and safer treatment option
Why do some provides recommend ACEi for years after treatment of arrhythmia induced cardiomyopathy?
Because fibrosis can remain for several years
What is the relationship between lung volume and PVR?
Parabolic (U-shape)
What is a typical tidal volume?
5-6mL/kg of ideal body weight
What happens to PVR when tidal volume increases?
It increases:
-More inspiratory capacity used
-Alveoli in lungs become overdistended and functionally compress pulmonary vasculature between each alveolus
-Resistance to flow in the pulmonary blood vessels increases
Increased airway pressure leads to vascular stretch and secondary basoconstriction
What happens to PVR when tidal volume decreases?
It decreases:
- As more of expiratory reserve is released, alveoli collapse and become atelectatic
- Alveoli become hypoxia which leads to reactive vasoconstriction
- Associated pulmonary vasculature is compressed
- Increased PVR
Ideal expansion of the alveoli and surrounding vasculature occurs at what mark?
Functional residual capacity
When is PVR the lowest during the respiratory cycle?
At functional residual capacity
Hyperinflation or underinflation of the lungs does what to PVR?
Increases it
Optimal cardiopulmonary interaction occurs with lung volumes at what?
Functional residual capacity
What is the most common age for an initial gap in cardiology care?
19.9 years
- Graduating high school, college or new job, moving, family has less influence
- This is an at-risk time
Why do most CHD patients have gaps in care?
Didn’t know they needed follow-up
- Especially mild-mod complexity lesions
- All moderate complexity lesions need ACHD follow up and most mild CHD need ACHD follow-up
Why do CHD patients not seek cardiology consultation?
They felt well
-Symptoms are unreliable and often a late manifestation of disease progression (ex. ToF patients needed a new PV)
True or False: Gaps in transition of care from pediatric to ACHD are common
True
True or False: Young adults around 25 years are at highest risk for gaps in care for CHD
False- 20 years
What are symptoms of digoxin toxicity?
Anorexia, nausea, vomiting, vision disturbances (yellow hue or blurred vision), cognitive dysfunction, arrhythmias (atrial or ventricular tachycardia), conduction disturbances
What is the classic atrial tachycardia seen with digoxin toxicity?
Atrial tachycardia with variable degrees of AV block
What is the classic ventricular tachycardia seen with digoxin toxicity?
Bidirectional ventricular tachycardia
List some common medications used in cardiology that can raise digoxin levels
- Carvedilol
- Amiodarone
- Spironolactone
- Verapamil
May need to decrease digoxin dose or monitor closely when starting or increasing these medications
How do ACEi or diuretics affect digoxin levels?
- Via impairment in renal function
- Digoxin is cleared by the kidney, so with reduced kidney function, digoxin levels will increase
How is digoxin primarily eliminated?
Unchanged by the kidney
*Worsening renal function can increase digoxin level and potential for toxic effects
True or False: ASA can impair renal function
True- but only at high doses
When should digoxin antibody (digoxin immune Fab) be used?
For digoxin toxicity leading to progressive or life-threatening arrhythmias or concern for progressive conduction disturbance
In a patient with an ASD and moderate pulmonary HTN, what should be done if the pulmonary vascular bed is reactive?
Close the ASD
The calculation for resistance is based on what?
Poiseuille’s Law
What is the equation for resistance?
Change in pressure across a vascular bed/Flow across the vascular bed
What is the equation for PVR?
Mean LA pressure - Mean PA pressure/Qp
What is the equation for Qp in 100% O2?
VO2/O2 content of PV-O2 content of PA
VO2/{[(PV sat)(Hgb)(13.6)]+(0.03PaO2PV)} - {[(PA sat)(Hgb)(13.6)]+(0.03PaO2PA)}
What is the same as the PV PaO2 assuming no R-L shunting?
The systemic PaO2
What should be done prior to ASD closure in a patient with elevated pulmonary pressure?
Cath to calculate PVR and pulmonary vascular bed reactivity
After what surgeries is post-pericardiotomy syndrome commonly seen?
- ASD*
- Systemic to PA shunts
- Transplant
- Pacemaker/ICD lead placement
- Acute MI (Dressler syndrome)
- Blunt cardiac trauma
- RF ablation (Rare)
What should also be on the differential for post-pericardiotomy syndrome?
Acute viral pericarditis
What causes post-pericardiotomy syndrome?
Unclear
-Likely due to an autoimmune inflammatory reaction of the pericardium +/- development of a hemodynamically significant pericardial effusion
*Increased incidence of this in patients on immunosuppression after transplant which support etiology being potentially cellular-mediated immune response
What are the common clinical findings in post-pericardiotomy syndrome?
- Fever with no evidence infection
- Irritability
- Malaise
- Decreased appetite
- Pleuritic chest pain
What are common physical exam findings in post-pericardiotomy snydrome?
- Tachycardia
- Pericardial and/or pleural friction rub
What lab findings are consistent with post-pericardiotomy syndrome?
- Elevated CRP
- Elevated ESR
- Elevated WBC
- Elevated platelet count
- Minimal elevation in Tn T
True or False: Significantly elevated Tn is consistent with post-pericardiotomy syndrome?
False
What ECG findings are consistent with post-pericardiotomy syndrome?
- Diffuse ST-segment elevation
- T-wave inversion
- PR depression
What can be seen on CXR in post-pericardiotomy syndrome?
Cardiomegaly (if significant pericardial fluid)
Pleural effusion
What is a common echo finding in post-pericardiotomy syndrome?
Pericardial effusion
What is seen on CT scan in post-pericardiotomy syndrome?
Increased pericardial thickness
What is the most sensitive method to assess for pericardial inflammation?
CMR
What is seen on CMR that suggests pericardial inflammation?
Hyper-enhancement of pericardium on LGE imaging
True or False: Post-pericardiotomy syndrome is generally self-limited?
True
What types of medical therapy are used in post-pericardiotomy syndrome?
ASA
NSAIDs (ibuprofen)
Steroids (Refractory cases)
Colchicine
What is a risk of steroids used in post-pericardiotomy syndomre?
May lead to rebound symptoms and increased recurrence risk when stopped
What are some benefits of colchicine when used in post-pericardiotomy syndrome?
- May avoid rebound symptoms seen with steroid treatment withdrawal
- Decreases rate of post-pericardiotomy syndrome when used prophylactically following surgery
Recurrent pericardial effusion can occur in what % of patients with post-pericardiotomy snydrome?
10-15%
*Smaller subset may go on to develop constrictive pericarditis months-years later
Which is more common, orthodromic AVRT or antidromic AVRT?
Orthodromic
Describe the circuit in orthodromic AVRT
- Down the AV node (antegrade limb)
- Up the accessory pathway (retrograde limb)
Is the QRS complex narrow or wide in orthodromic AVRT?
Narrow (ventricles are activated via AV node and His-Purkinje system)
Orthodromic AVRT can occur in patients with what 2 types of pathways?
- Manifest (WPW)
- Concealed (not WPW)
True or False: Patients with WPW or ventricular preexcitation can orthodromic and antidromic AVRT?
True- Orthodromic more common
Describe the circuit in antidromic AVRT
- Down the accessory pathway (antegrade limb)
- Up the AV node (retrograde limb)
Is the QRS complex narrow or wide in antidromic AVRT?
Wide (maximally pre-excited)- Ventricles are activated exclusively via AP
*Mimics ventricular tachycardia
A wide complex tachycardia should be considered what until proven othewise?
V-tach
What is a clue on resting ECG that a wide complex tachycardia may be due to antidromic AVRT?
WPW/preexcitation
During an EP study, if there is earliest ventricular activation in the lateral CS lead, where is the pathway?
Left lateral accessory pathway
What tachycardia would do an ablation of the earliest pre-systolic Purkinje potential in?
Fascicular ventricular tachycardia
What is fascicular ventricular tachycardia?
Re-entrant tachycardia with the circuit in the LV using the anterior or posterior fasicle
What does fascicular ventricular tachycardia typically look like?
RBBB pattern with LAD
What is the most common form of ventricular tachycardia in a structurally normal heart?
RVOT tachycardia
Where do you ablate for RVOT tachycardia?
Focus in the RVOT
Describe the appearance of RVOT tachycardia
LBBB pattern with inferior axis
True or False: RVOT tachycardia is not typically inducible with programmed stimulation?
True
True or False: If a tachycardia is caused by something like commotio cordis or myocarditis, it is unlikely to recur
True
Commotio cordis presents with what type of arrhythmia?
Ventricular fibrillation
What is an uncommon form of tachycardia which is associated with ventricular preexcitation, with the accessory pathway as the antegrade limb and the AV node as the retrograde limb?
Antidromic AVRT
Describe the surface QRS in antidromic AVRT
Very wide (maximally pre-excited)
True or False: Ablation is curative of antidromic AVRT
True
What is the differential diagnosis of wide complex tachycardia?
- Ventricular tachycardia
- Antidromic AVRT
- SVT with aberrancy
