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