PREP 2020 Flashcards
How can you improve arterial saturation in a post-op Glenn patient with overinflated lungs?
Decrease PEEP- this will return lung volumes to FRC and increase PBF
What circumstance would it be disadvantageous to decrease PEEP in a post-op Glenn patient?
When there is pulmonary edema- this will worsen alveolar O2 exchange and worsen saturations
How does increasing minute ventilation in a post-op Glenn patient effect saturation?
Decrease saturation
-Increased minute ventilation will decrease pCO2, which causes cerebral vasoconstriction, which causes reduced cerebral blood flow which results in decreased return of venous flow through the Glenn which causes desaturation
What are the 2 terms that describe the quantity and relationship of O2 in the blood?
Content
Saturation
How is O2 content expressed?
mL of O2 per 100mL blood
How is oxygen saturation (SaO2) expressed?
Percentage of binding sites on Hgb that are occupied by O2
Healthy individuals with no lung disease breathing room air at sea level have SaO2 between what?
96-98%
What factors affect the O2 content of blood?
PO2
Ventilation and perfusion mismatch
Hgb affinity for O2
Concentration of Hgb
When normally saturated Hgb is circulated to tissues, what % of bound O2 is delivered to the tissues?
25%
What is the typical systemic venous saturation returning to the right side of the heart ?
75%
What is the difference in the saturation of blood leaving the aorta and returning to the right heart?
a-vO2 difference
With normal CO/metabolic demand and no other shunting, what is the average a-vO2 difference?
25 points
What causes a decreased systemic venous saturation and widened a-vO2 differenve?
- Increased metabolic demand- tissues may require more O2 than normal
- If heart unable to upregulate output to meet the demand, tissues will extract more O2 from Hgb than normal leading to a decreased systemic venous saturation and widened a-vO2 difference
What happens to the saturation of Hgb returned from the lungs in the setting of lung pathology (pulmonary edema, PNA, etc)?
Can be decreased
-Ability of the alveoli to transfer O2 to pulmonary arterioles is limited
In the setting of lung pathology, what plays a key role in the determination of the SaO2?
Partial pressure of O2 (O2 tension)
What represents the partial pressure when gases are mixed?
Sum of the pressures that each gas in the mixture exert if alone
When a mix of gases comes into contact with a membrane across which they can diffuse, what is the rate of diffusion dependent upon?
Relevant gradient of the partial pressure of the gas across the membrane (not the concentration of the gas)
True or False: Concentration and partial pressure have a direct relationship in the gas phase?
True
Why is blood able to carry large concentrations of O2?
Hgb high affinity for O2
How do increases in mean airway pressure or addition of supplemental O2 lead to an increase in arterial O2 saturation?
By increasing alveolar partial pressure of O2
How does positive airway pressure improve alveolar O2 tension?
Recruits collapsed alveoli
What can help to increase alveolar O2 tension in regions of low ventilation?
Supplemental oxygen
Lung pathology (pulmonary edema or PNA) can lead to what?
Pulmonary venous desaturation
What measures can improve pulmonary venous and systemic saturation?
- Increasing airway pressure
- Supplemental O2
*Both can increase alveolar O2 tension, improve diffusion and improve pulmonary venous and systemic saturation
What causes LQTS3?
Gain of function mutation on SCN5A (regulates cardia Na channels
True or False: B-blockers help decrease the number of arrhythmic events in patients with LQTS3, but not to the same extent as 1 and 2?
True
What medication reduces the number of arrhythmic events in patients with LQTS, in particular those with type 3 disease?
Mexiletine
How does mexiletine work?
- Class IB antiarrhythmic
- Inhibits inward Na current
- By blocking late Na current, leads to decrease of AP duration and shortens the ERP
Amiodarone, dofetilide and sotalol are what class of antiarrhythmics?
III
How do class III antiarrhythmics work?
- Inhibit K delayed rectifier currents during phase 2 of the AP
- Prolong AP duration and ERP
What change is seen on ECG in patients receiving class III antiarrhythmics?
Prolongation of the QT interval
Class III antiarrhythmics are contraindicated in patients with what?
Long QT syndrome
True or False: All class III antiarrhythmics have the potential to be pro-arrhythmic?
True- TdP and ventricular arrhythmias most concerning
What needs to be monitored on all patients started on a class III antiarrhythmic?
ECG for the QTc
What are possible side effects of amiodarone?
- Thyroid dysfunction (hypo or hyper)
- Skin discoloration
- Photosensitivity
- Hepatitis
- Corneal deposits
- Pulmonary toxicity
- Pro-arrhythmic
What medication can be effective in the treatment of patients with long QT syndrome type 3?
Mexiletine
What class of antiarrhythmics are contraindicated in patients with LQTS?
III
What is the best testing to make a diagnosis of aortic dissection?
CTA
What is the classification system what categorizes aortic dissection based on anatomic location?
Stanford
What is a type A aortic dissection?
Involves the ascending aorta
What is a type B aortic dissection?
All other dissections besides those involving the ascending aorta
What is the most common type of aortic dissection?
A
True or False: In aortic dissection, the site of the primary intimal tear doesn’t determine classification?
True
- Type A doesn’t have to originate in or be confined to the ascending aorta
- Type B cannot include the ascending aorta
What is a potential, but uncommon complication of aortic stent placement?
Aortic dissection
What patient group is at increased risk of spontaneous aortic dissection and iatrogenic dissection?
Turner
What is the most common presenting symptom of an aortic dissection?
Sudden onset of chest or abdominal pain described as sharp, tearing or ripping
*Chest pain or back pain is more common than abdominal pain
What type of aortic dissection is more likely to be associated with anterior chest pain?
Type A
What type of aortic dissection is more likely to be associated with back pain?
Type B
With an aortic dissection, the presence of abdominal pain should raise suspicion for what?
Mesenteric vascular compromise from dissection extending into abdominal aorta
Besides chest/back/abdominal pain, what are other signs and symptoms of an aortic dissection?
Pulse deficit, heart murmur (new AI if type A involves aortic valve), focal neurologic deficits, hypotension
What should be considered for someone with abdominal pain and HTN after stent placement?
Post-coarctectomy syndrome
*Usually postsurgical phenomenon
What causes postcoarctectomy syndrome?
Paradoxical HTN as a result of rebound activation of the sympathetic nervous system and renin-angiotensin system
How does postcoarctecomty syndrome cause abdominal pain?
Paradoxial HTN can be severe and result in mesenteric arteritis leading to abdominal pain
Besides a CTA, what other tests can help with diagnosis of an aortic dissection?
TEE and MRI
*TTE or abdominal US aren’t as sensitive or specific as a TEE or MRI
What is seen on CXR in aortic dissection?
Mediastinal widening (most common in type A, but also occurs in type B)
Stent-associated aortic dissection may be increased in patients with what condition?
Turner
What are causes of palpitations?
- Arrhythmias (SVT, v-tach, PACs, PVCs)
- Anxiety/emotions
- Anemia
- Hyperthyroidism
- Fever
- Medication effects
- Inappropriate sinus tachycardia
- POTS
What is a form of autonomic dysfunction which includes palpitations and presyncope with prolonged standing or physical activity, gradual improvement of symptoms with rest in the seated or supine position, generalized fatigue, nausea, mental clouding and dependent bluish discoloration of the lower extremities?
POTS
True or False: A gradual improvement in palpitations and presyncopal symptoms is not consistent with an arrhythmia?
True
*Arrhythmia more likely if abrupt onset and termination described
What type of patients most often get POTS?
Females between 15-25 years
How is POTS diagnosed?
Increase in HR (>30 for adults or > 40 for pediatrics) without a decrease in BP (>20mmHg drop in SBP) within 10 minutes of moving from a supine to standing position
What are more detailed testing options for the diagnosis of POTS?
- Measurement of supine and upright plasma epinephrine and norepinephrine levels
- Thermoregulatory sweat test
*Not typically used and POTS often diagnosed by orthostatic vital signs alone
True or False: Most patients with d-TGA don’t have a genetic syndrome?
True (96%)
In patients diagnosed with DiGeorge, what % have d-TGA, ToF and TA?
- d-TGA: 1%
- ToF: 20%
- TA: 6%
What % of patients with Turner syndrome (45,X) have cardiac disease?
50%
What are most common cardiac issues in Turner syndrome?
Bicuspid AoV, CoA, dilated ascending aorta
Trisomy 21 has what % incidence of CHD?
50%
What are the majority of congenital heart defects seen in trisomy 21?
-Septation: AVSD, VSD, ASD
What % of d-TGA patients have non-cardiac anomalies?
<10%, very low compared to others
What is the most common associated cardiac anomaly in d-TGA?
VSD (up to 50% of cases)
What is more common in the setting of d-TGA and a malalignment VSD?
LVOTO (can also include PV abnormalities)
True or false: TGA isn’t strongly associated with any particular genetic syndrome?
True
Defects in genes that control what are associated with TGA?
Laterality
What causes Ebstein anomaly?
Failure of delamination of the septal and posterior leaflets of the TV leading to apical and anterior displacement of the functional TV annulus into the RV and valve dysfunction
What is the atrialized portion of the RV in Ebstein?
Portion of RV proximal to the functional annulus which becomes thin-walled
True or False: The severity of Ebstein anomaly can vary greatly?
True-
- Mild: Minimal TV dysfunction and few symptoms
- Severe: Small portion of normal RV, severe TR, little to no effective anterograde flow through right side of heart
According to newer studies, what is the perinatal mortality rate associated with fetal diagnosis of Ebstein anomaly?
40-50% (used to be up to 80%)
What problems result from severe tricuspid valve dysfunction in utero that lead to increased parinatal mortality in Ebstein?
- Right heart dilation due to back/forth flow (especially RA and atrialized RV)
- Progressive dilation can cause cardiomegaly which may lead to lung hypoplasia
- Decreased CO (poor RV output and impaired LV hemodynamics due to RV dilation)
What are the potential problems that can develop in utero with the RV and RVOT in Ebstein?
- RV can be dysfunctional
- May have functional PA- RV can’t overcome afterload to open PV
- Poor flow through the RVOT early in gestation can lead to a structural RVOTO or anatomic PA
- PA results in L-R ductal shunting
- With functional pulmonary atresia, may develop PI which further increases volume load on RV
What may be needed for neonates with Ebstein and anatomic PA or significant RVOTO after birth?
Ductal patency for adequate pulmonary blood flow… will require intervention in neonatal period to establish a stable source of pulmonary blood flow
What should be considered regarding the PDA in an infant with Ebstein and functional PA?
- As PVR falls normally, RV may be able to generate sufficient pressure to overcome afterload and open PV
- Keeping PDA open may be counter-productive because it would keep afterload high in RV and limit this forward flow
The presence of PI in patients with Ebstein and functional PA is indicative of what?
High RV afterload
The presence of PI in patients with Ebstein and functional PA leads to what?
Circular shunt and further volume loading of the right side of the heart
What predictors of a poor outcome in Ebstein anomaly seen on fetal echo?
- Pulmonary insufficiency
- Pulmonary atresia (functional or anatomic)
- Severe RA and atrialized RV dilation
- Increased CT ratio
- Hydrops
- Larger TV annulus
- LV dysfunction
- Low TR jet velocity
What is the Celermajer index?
Ratio of the area of the RA and atrialized RV to the area of the normal portion of the RV and LA/LV
- Measured using 4C of fetal heart
- Higher number implies higher risk for mortality
True or False: ASD are seen in most patients with Ebstein anomaly?
True
What % of patients with Ebstein have WPW?
10-30%
True or False: Arrhythmias during gestation increase perinatal mortality in Ebstein?
False- Can occur during gestation, but haven’t been shown to have a large effect on perinatal mortality
*Arrhythmias are overall common in patients with Ebstein anomalty
Fetuses with Ebstein and what finding on fetal echo throughout gestation have the highest rates of survival and biventricular circulation?
Antegrade pulmonary blood flow (R-L ductal shunting)
How does severe Ebstein anomaly lead to functional PA?
When RV is unable to generate enough pressure to open PV
Which fetuses with Ebstein are at the highest risk for perinatal mortality?
- Severe right-sided heat dilation
- PI
- Absence of anterograde pulmonary blood flow
- Hydrops
- LV dysfunction
What physical exam finding is consistent with pulmonary hypertension?
Single, loud S2
High-frequency systolic murmur along LLSB?
Tricuspid regurgitation
When do most patients with cor triatriatum have onset of symptoms?
Within first few years of age
*Symptoms of PH can be subtle or midleading and delay diagnosis (may be diagnosed with asthma, etc)
What is the management of patients with cor triatiatum and elevated PA pressure?
Surgical resection of the obstructive membrane
What has to be ruled out in the evaluation of pulmonary hypertension?
Left-sided obstructive heart lesions
*Echo +/- CT if echo inconclusive or if lung pathology is a concern
What could happen with the use of O2 or a pulmonary vasodilator in cor triatriatum?
May worsen pulmonary edema and clinical status
True or False: There are many anatomic variants of cor triatriatum?
True
What is it called when all or some of the pulmonary veins enter a pulmonary venous chamber that joins the LA through a narrowed opeining?
Cor triatriatum
What are the signs and symptoms of obstructive cor triatriatum?
Pulmonary venous obstruction (pulmonary HTN and right-sided heart failure)
True or False: An isolated right aortic arch with left-sided ductus arteriosus and aberrant left subclavian results in a vascular ring?
True
What are vascular rings?
Heterogenous group of vascular abnormalities that encircle the trachea and esophagus
How is a fetal right aortic arch identified?
When the transverse aortic arch passes to the right of the trachea
How is a left arterial duct identified on a fetal echo?
Passes to the left of the trachea
How does a right aortic arch with left ductus appear on fetal echo in comparison to a left-sided aortic arch and left duct?
- Right arch/left duct appears U-shaped
- Left arch/left duct appears V-shaped (both pass on the same side of the trachea)
What is the path of an aberrant left subclavian artery off of a right aortic arch on fetal echo?
Arises distally off the aorta, courses from right side of spine behind trachea/esophagus and heads left
True or False: Patients with a vascular ring due to a right aortic arch, left duct and aberrant left subclavian artery rare have symptoms of airway or esophageal compression in the neonatal period?
True
About what % of patients with a right arch, left duct and aberrant left subclavian artery develop symptoms of compression (dysphagia, stridor, recurrent URIs)?
20-25%
At what age do patients with right arch, left duct and aberrant left subclavian artery develop symptoms of compression (if they ever develop these) on average?
7 months
Fetal right aortic arch without intracardiac abnormalities is associated with extracardiac malformations involving what?
GI system or urinary tract
*Esophageal atresia can rarely be seen with this
Up to 10% of patients with an isolated right aortic arch have what genetic finding?
22q11.2 gene deletion
What should be offered to all patients with an isolated right aortic arch?
Genetic testing (looking for 22q11.2 deletion
What are the 4 goal of prenatal counseling following a diagnosis of CHD?
- Accurate diagnosis of the malformation
- Clear/truthful picture of the prognosis
- Outlining available management and treatment options
- Help parents reach decisions concerning form of management that is best for them
Prenatal counseling should offer information on that things?
- Nature of the specific diagnosis
- Possible associations with specific genetic anomalies
- Natural history
- Range of treatment and management strategies
- Long-term post-natal prognosis
True or False: Right aortic arch with aberrant left subclavian artery is associated with extracardiac and genetic anomalies including 22q11.2 deletion?
True
True or False: Most patients with a prenatal diagnosis of right aortic arch don’t become symptomatic or require surgical intervention
True
The current PALS guidelines for pulses v-tach or v-fib include what?
- High quality CPR
- Quick defibrillation with 2-4 J/kg
What should be considered in cases of shock-refractory pVT/VF?
Lidocaine or amiodarone
*If patient has LQTS as cause of arrest, avoid amiodarone
Amiodarone should be avoided in what patients?
LQTS
What class is amiodarone?
III
Why does amiodarone increase the risk of ventricular arrhythmias in LQTS patients?
Leads to QT prolongation
Besides lidocaine or amiodarone, what can be considered in cases of torsades de pointes which is refractory to defibrillation?
Mg Sulfate
How does adenosine work?
Blocks the AV node
Adenosine can be used as a treatment option in patients with what rhythms?
- SVT
- Wide QRS tachycardia that is stable with a pulse
What is one of the most common causes of a wide QRS tachycardia in children?
SVT with aberrancy
Besides lidocaine or amiodarone, what are 2 other medications that can be used for ventricular arrhythmias, but aren’t part of PALS guidelines for pVT/VF?
Sotalol and emolol
What class is sotalol?
III
Which patients should you avoid sotalol in?
LQTS
What should be considered in cases of shock-refractory pulseless ventricular tachycardia or ventricular fibrillation?
Lidocaine or amiodarone
What should be done immediately for pulseless ventricular tachycardia or ventricular fibrillation?
Quick defibrillation with 2-4J/kg
What anti-arrhythmics should be avoided in patients with known or suspected LQTS?
Class III anti-arrhythmic agents (amiodarone, sotalol, etc)
What can occur after CPB that contributes significantly to morbidity and mortality in pediatric cardiac patients?
AKI
Cardiac-surgery AKI is reported in up to what % of pediatric patients?
33-50%
Cardiac-surgery associated AKI is associated with what?
More complex surgeries and longer CPB time
What should be considered in a post-op patient with low urine output or electrolyte abnormalities?
AKI
What should be considered when prescribing medications for a post-op patient?
Risk for nephrotoxicity with potential AKI…renally dose meds and avoid nephrotoxic meds as able
What is newest and most commonly used system to categorize AKI?
Kidney Disease: Improving Global Outcomes (KDIGO)
What are the 2 factors considered in the KDIGO classification system for AKI?
Serum creatine and urine output
What are 2 newer biomarkers which may be used in the monitoring of renal function after cardiac surgery?
- NGAL (neutrophil gelatinase-associated lipocalin)
2. Cystatin-C
What are some medications commonly used in pediatric cardiac patients that may need dose-adjustment based on renal dysfunction?
- Vancomycin
- Enoxaparin
- Cefepime
- High-dose ASA
- NSAIDS (ibuprofen)
- Aminoglycosides (gentamicin)
- Histamine receptor antagonists (ranitidine)
- ACEi
- Certain diuretics
- Narcotics (morphine)
True or False: Low-dose ASA hasn’t been linked to an increased risk of nephrotoxicity?
True- Dose adjustments not needed unless GFR is <10
Urine output < what is a sign of AKI according to the KDIGO classification system?
<0.5mL/kg/hr (for 6-12 hours)
An increase in creatine level to greater than what from baseline is a sign of AKI according to the KDIGO classification system?
> 150% from baseline
What is stage 1 AKI per KDIGO?
- Serum creatine 1.5-1.9 times baseline or >0.3mg/dL increase
- UOP <0.5mL/kg/hr for 6-12 hours
What is stage 2 AKI per KDIGO?
- Serum creatine 2-2.9 times baseline
2. UOP <0.5mL/kg/hr for >12 hours
What is stage 3 AKI per KDIGO?
- Serum creatine 3 times baseline or increase in serum creatine to >4mg/dL or initiation of renal replacement therapy or in patients <18 years decrease in eGFR to <35mL/min
- UOP <0.3mL/kg/hr for >24 hours or anuria for >12 hours
What is a risk with benign ventricular ectopy?
Tachycardia induced cardiomyopathy
In adults, tachycardia-induced cardiomyopathy is unlikely with a % PVC burden under what?
16-24%
*Some cases have been reported with PVCs low as 10%
What is the PACES/HRS recommendation for follow-up in children with ventricular ectopy and a structurally normal heart?
Longitudinal follow-up of patients with >10% burden of PVCs to monitor for progression to cardiomyopathy
What needs to be ruled out when evaluating a patient with PVCs?
Rule out any malignant causes of arrhythmia (myocarditis, cardiomyopathy, tumors, CPVT, LQTS, ARVC, etc)
What should be done as part of the workup for a patient presenting with PVCs?
ECG, echo, Holter, personal history, family history, exercise stress test
An exercise stress test in a class 1 recommendation in patients with what type of ventricular ectopy?
Multiform or complex (bigeminy, couplets, NSVT)
An exercise stress test is a class 2A recommendation in patients with what type of ventricular ectopy?
Simple (no bigeminy, couplets, NSVT)
True or False: The early stages of ARVC can present with monomorphic PVCs of RVOT origin and can be difficult to diagnose?
True
In addition to history, physical, ECG, echo, exercise stress test and holter, what other things are recommended when there is suspicion for ARVC?
- MRI (2a for children, 2b for older infants)
- Signal-averaged ECG (2b)
What factors would raise clinical suspicion for ARVC?
- RV wall motion abnormality on echo
- RVOT enlargement on echo
- Abnormal T-wave inversion in anterior precordial leads in patients >14 years
- Epsilon wave on ECG
- V-tach with LBBB morphology and superior axis
- Concerning family history
Besides ECG, Holter, echo, exercise test and H&P what should be done for a patient with incessant or complex ventricular ectopy?
MRI (class 2a) to rule out myocarditis
True or False: Isolated, monomorphic ventricular ectopy in patients with structurally normal hearts is typically benign
True
In patients with ventricular ectopy, what baseline testing should be done at a minimum to rule out malignant causes of arrhythmia?
- ECG
- Echo
- Holter
What testing in addition to ECG, echo and holter should be strongly considered in the setting of multiform or complex ventricular ectopy?
Exercise stress test
What specific testing is helpful with concern for ARVC?
CMR or signal-averaged ECG
What specific testing is helpful with concern for myocarditis in the setting of incessant or complex ventricular ectopy?
CMR
What with an ectopy burden > what should be followed longitudinally to ensure that ventricular function remains normal?
10%
Complete heart block with marked bradycardia, elevated CRP, Tn, BNP, normal systolic function, trivial pericardial effusion?
Viral myocarditis
True or False: Complete heart block is a fairly unusual, but well described finding in viral myocarditis?
True
Why would complete heart block result in fatigue and syncope?
Heart can’t increase CO in response to activity due to the heart block
What are common symptoms of viral myocarditis?
Dyspnea, chest pain
What is myocarditis?
Generic term to describe an inflammatory response of the myocardium to pathologic agents (infectious or noninfectious)
What is the most common cause of infectious myocarditis?
Viral (but can also get bacterial, fungal, parasitic, rickettsial and protozoal)
What are some non-infectious causes of myocarditis?
- Autoimmune (SLE or rheumatic fever)
- Medications
- Kawasaki disease
What is the gold standard test to confirm the presence of myocarditis?
Endomyocardial biopsy demonstrating myocardial inflammation
*Seldom done in real life
What if the favored diagnostic modality for myocarditis?
CMR- Detects myocardial edema and/or inflammation
Besides viral myocarditis, what are the most common etiologies for myocarditis presenting with heart block?
Lyme disease
SLE
What are arrhythmias that commonly occur with acute and subacute myocarditis?
Atrial and ventricular tachyarrhythmias
- Can also see complete heart block
- Presence of arrhythmias associated with a worse outcome
True or False: Despite clear evidence that IVIG improves outcomes in myocarditis, many centers will give IVIG to patients with fulminant myocarditis, hemodynamic instability and/or potentially lethal arrhythmias like complete heart block)
True
What is the most common ECG finding in acute rheumatic fever?
Prolonged PR interval (varying degrees of heart block)
When does congenital complete heart block typically present?
At birth or shortly after (rarely can be seen in older children)
True or False: Complete heart block is a common arrhythmia seen in Kawasaki?
False
True or False: Complete heart block is an unusual, but well-described presenting sign of acute myocarditis in children?
True
True or False: Most patients with arrhythmias or conduction disturbances associated with acute myocarditis will have resolution of their arrhythmias/conduction disturbances as their myocarditis resolves?
True
*But recurrent/persistent arrhythmias have been reported
What is the preload reservoir for the RV?
Systemic venous bed (outside of the thorax)
What is the preload reservoir for the LV?
Pulmonary vascular bed (within thorax)
What is the afterload reservoir for the RV?
Pulmonary vascular bed (within thorax)
What is the afterload reservoir for the LV?
Systemic arterial bed (outside of thorax)
How does an increase in intrathoracic pressure affect the RV?
Increase afterload
Increase workload
If there is impairment of the systolic or diastolic RV function, what does an increase in intrathoracic pressure result in?
- Increase in RV workload
- Decrease in output of the RV
- Decrease in preload to the LV
- Decrease CO
How was a increase in intrathoracic pressure effect the LV?
- Decrease afterload
- Decrease workload
If there is impairment of the systolic or diastolic LV function, what does an increase in intrathoracic pressure result in?
- Decrease in transmural gradient (pressure difference between the intrathoracic LV cavity and extrathoracic systemic vascular space)
- Pressure difference LV has to overcome to eject same volume decreases and CO increases
*What is seen in positive-pressure mechanical ventilation
How does an increase in PEEP influence intrathoracic pressure?
Increases it
An increase in intrathoracic pressure has what effect on the RV?
- Increased afterload
- Can result in impairment and decreased output in a noncompliant/hypertrophied RV
With a R-L shunt, which is higher, measured arterial pCO2 or expired end-tidal pCO2?
Measured arterial pCO2
*With a R-L shunt, a portion of the CO never reaches the lungs to exchange pCO2
In a R-L shunt, what does the arterial-to-expired pCO2 gradient correlate with?
Degree of R-L shunt
- Ex: If Qp:Qs = 0.6:1 and arterial pCO2 = 55, end tidal pCO2 would be 33
- 0.6/1 = 33/55
Arterial to end-tidal pCO2 gradients are common and expected in patients with what type of shunt?
R-L
Arterial to end-tidal pCO2 gradients directly correlate with what?
Degree of shunting
CoA is associated with a bicuspid AoV in what % of cases?
50-80%
What are long-term issues in regard to repaired CoA of the aorta?
- Aneurysm at site of prior repair
- Residual stenosis or re-coarctation
- Long-term HTN
- Increased risk of acquired CV disease
- Cerebral aneurysm
- Other associated left-sided heart obstructive lesions
What are long-term concerns in patients with bicuspid AoV?
- Progressive stenosis or regurgitation
- Resultant LV effects: Hypertrophy, dilation, dysfunction
- Ascending Ao aneurysm
A dilated AscAo > what is considered a class I recommendation for surgical replacement of the ascending aorta?
> 5.5cm
In which individuals would you consider surgery for aortic dilation >5cm?
- Family history of early dissection
- Personal history of rapid progression
- Aortopathies (may be considered at a center for excellence in aortopathy)
*Otherwise, intervene at >5.5cm
For stenosis or regurgitation with a bicuspid AoV, what is the indication for intervention largely based on?
Symptoms
In chronic AI, if the regurgitation is considered severe and LV function is preserved, it is reasonable to consider AoV replacement if the LVESD is > what?
50mm
In chronic AI, if the regurgitation is considered severe and LV function is preserved, it is reasonable to consider AoV replacement if the LVEDD is > what?
65mm
In an asymptomatic person with severe AS and a peak velocity >4M/sec, AoV replacement may considered under what circumstances?
- LVEF <50%
- Abnormal exercise stress test with decreased exercise tolerance or fall in BP
- Undergoing other cardiac surgery
True or False: The echo gradient at the level of the aortic isthmus is often overestimated following CoA repair?
True
What are the indications for surgery in the setting of re-CoA after repair?
- Clinical cuff gradient differential of at least 20mmHg
- Evidence of significant gradient and collateral vessels (usually seen by 3D imaging)
A dilated AscAo > what is considered a class I indication for surgery in patients with bicuspid AoV associated aortopathy?
> 5.5cm
In cases of bicuspid AoV with resultant AS or AI, what help guide indications for surgery?
Symptoms
Individuals with repaired CoA and cuff gradients > what may be considered for intervention?
20mmHg from upper to lower extremity
What is the definition of DORV with noncommitted VSD?
- VSD distant (greater than aortic diameter) from both arterial valves
- Both great vessels arising fully from the RV
- Double conus
*Others have described non-committed VSDs as those that don’t open between the limbs of the septal band (like they do in other forms of DORV)
What is a significant risk following intracardiac baffle repair of a remote VSD in DORV with noncommitted VSD?
LVOTO (can be late onset)
Where are most stenoses seen in LVOTO following intracardiac baffle repair of a remote VSD?
- Aortic annulus
- Baffle-patch/muscular structures
- VSD
*LV undergoes geometric changes in which the VSD is used as a new LVOT pathway… bulge of the underlying septal or subaortic conal muscle is often main cause of obstruction (v. Ao annulus and tunnel entry stenosis)
What is a proposed reason for late-onset LVOTO following following intracardiac baffle repair of a remote VSD?
Somatic outgrowth…material for intracardiac baffle is unable to grow
What is repair of DORV with non-committed VSD and normally related great arteries associated with?
Late-onset complex LVOTO
What levels can LVOTO after intraventricular tunnel repair to the aorta develop at?
- Aortic annulus
- Baffle patch/muscular structures
- VSD
True or False: In all cases of IAA, the femoral pulses are reduced and the lower extremity saturations are decreased?
True
In IAA, absence/reduction of the brachial pulses and decreased upper extremity saturations suggests what anatomy?
Both subclavian arteries arising distal to the interruption
*Like IAA B with aberrant subclavian
True or False: An infant with IAA type B with an aberrant subclavian artery would be expected to have weak carotid pulses?
False
What is IAA type B with an aberrant subclavian artery commonly associated with?
DiGeorge
What is a complete separation of the ascending and descending aorta?
IAA
Where is the interruption in IAA A?
Distal to the most distal subclavian artery (usually left subclavian artery)
Where is the interruption in IAA B?
Between the left carotid and subclavian arteries
Which type of IAA is frequently associated with DiGeorge?
B
Which type of IAA has a high incidence of an aberrant right subclavian arising from the descending aorta?
B (some estimates high as 50%)
Where is the interruption in IAA B?
Between the carotid arteries
What are the key physical exam findings in all types of IAA?
- Differential cyanosis
- Differential pulses
- Usually between upper and lower extremities
- If aberrant subclavian, between head and extremities
True or False: Most patients (>70%) with IAA have a VSD?
True
What type of VSD is often seen in IAA (50% of Type A, 75% in Type B)?
Posterior malaligned VSD
What is the result of the posterior malaligned VSD often seen in IAA?
LVOTO
Besides a VSD and potential LVOTO, what is another common finding in IAA?
Bicuspid AoV
Interrupted aortic arches are almost always which side?
Left
*Right IAA has been reported in DiGeorge, even rare variant of right aortic arch and aberrant subclavian
Which type of IAA is associated with DiGeorge?
B
An aberrant subclavian artery is most common in what type of interruption?
B (associated with DiGeorge)
What is the first-line therapy for a neonate with a hemodynamically significant PDA?
Pharmacologic closure (if no contraindications)
*Although some centers use device closure or surgical ligation as preferred initial management
What are the most commonly used medications to close a PDA?
Ibuprofen (IV or PO)
Indomethacin (IV)
How do ibuprofen/indomethacin close a PDA?
Inhibit cyclooxygenase (COX) which in turn decreases prostaglandin production, which should result in ductal closure
Indomethacin and ibuprofen result in ductal closure what % of the time when used in an extremely low birth-weight neonate?
70-80%
What are the adverse effects of indomethacin and ibuprofen when used for PDA closure?
- GI bleed
- Spontaneous intestinal perforation
- NEC
- Renal impairment
- IVH
Is ibuprofen or indomethacin preferred for closure of a PDA and why?
Ibuprofen- lower risk of NEC and transient renal insufficiency
The COV inhibitors (ibuprofen/indomethacin) are contraindicated in what neonates?
- Suspected NEC
- Grade 3 or 4 IVH
- Clinical bleeding tendency
- Thrombocytopenia with Plt <60
- UOP <1mL/kg/hr
- Serum creatine level >1.5
- BUN >20
What needs to be closely monitored in a neonate receiving ibuprofen or indomethacin for PDA closure?
- Bleeding
- Early signs of NEC
- Decreased UOP
- Increased creatine
- Decreased platelets
How many 3-day courses of ibuprofen/indomethacin can be used for PDA closure?
Typically 2… if duct remains open, additional doses unlikely to be effective
Besides the COX inhibitors, what other medication has been shown to result in ductal closure for a premature neonate with symptomatic PDA?
Acetaminophen
What are class I indications for placement of a permannent pacemaker?
- Complete AV block with a wide QRS escape rhythm
- Advanced 2nd/3rd degree AV block with symptomatic bradycardia, ventricular dysfunction or low CO
- Post-op advanced 2nd or 3rd degree AV block that isn’t expected to resolve or that persists at least 7 days after surgery
- Congenital 3rd degree AV block with complex ventricular ectopy
- Congenital complete AV block with a ventricular rate <55npm or with CHD and a ventricular rate <70npm
How can noninvasive testing like Holter or exercise stress testing be used in advanced 2nd or 3rd degree heart block?
- See if there is ever any conduction
- See how conduction changes with an increased catecholaminergic state
How is an EP study helpful in 2nd degree AV block?
Can be used to evaluate the level of block (supra-Hisian v. infra-Hisian)
True or False: Invasive testing of conduction isn’t usually indicated for complete heart block?
True
AV block with associated septal defect and bone abnormality in the upper extremity?
Holt-Oram
TBX5
Holt-Oram
When are accurate measurements of QTc ideally done?
Sinus rhythm with normal QRS
What effect does Theophylline have on the sinus node and AV conduction?
- Stimulate sinus node
- Not expected to enhance AV conduction
What should be done for a wide QRS escape rhythm in a patient with complete AV block?
Pacemaker (class I indication)
What are the risk factors for sudden death in patients with HCM?
- Severe septal hypertrophy >30mm or Z-score >6
- FHx of sudden death resulting from HCM
- Hypotensive response during exercise
- Unexplained syncope
- Ventricular tachycardia
*Newer data show significant delayed enhancement on CMR is additional risk factor for SCD
**Adult risk factors, not as well defined for pediatrics
How many risk factors need to present to indicated placement of an ICD as primary prevention in HCM?
1 for adults, pediatric centers usually prefer 2+
- Severe septal hypertrophy >30mm or Z-score >6
- FHx of sudden death resulting from HCM
- Hypotensive response during exercise
- Unexplained syncope
- Ventricular tachycardia
*Newer data show significant delayed enhancement on CMR is additional risk factor for SCD
True or False: LVOTO in HCM has not been correlated with SCD?
True
*LVOTO can cause symptoms and need for myectomy
What types of cardiomyopathy has preexcitation (WPW) been associated with?
- HCM
- LVNC
What circumstance can pre-excitation lead to SCD?
If there is atrial fibrillation in a patient with a rapidly conducting manifest accessory pathway
What illicit drugs can cause MI?
- Cocaine
- Amphetamines (MDMA, ecstasy, 3,4-methylenedioxymethamphentamine)
- Marijuana
How do cocaine and amphetamines cause MI?
- Activations of nervous system leading to tachycardia, hypertension and vasoconstriction (including coronary artery circulation)
- Coronary thrombosis
- Blocking Na/K channels leading to arrhythmia (only cocaine)
How does marijuana cause MI?
- Low-moderate doses stimulates the sympathetic nervous system leading to tachycardia, hypertension (though at higher doses, does the opposite activating the parasympathetic nervous system causing bradycardia and hypotension)
- Coronary vasospasm
When are the CV effects and risk of MI highest after marijuana use?
Within 1 hour
True or False: Marijuana can lead to atrial arrhythmias?
True- Marijuana has some EP effects like decreased AP duration and refractory period
What factors increase the risk of marijuana use for MI?
- Concomitant alcohol or tobacco use
- Concurrent use of other illicit drugs (cocaine, amphetamines, etc)
What form of marijuana is often more potent with more profound CV effects?
Synthetic cannabinoids (K2, spice, etc)
Under what circumstance would a central nervous system depressant (like opioids or benzodiazepines) cause tachycardia or hypertension?
Withdrawal
-Use on own leads to bradycardia and hypotension
What problems can chronic heavy alcohol use lead to?
Hypertension and cardiomyopathy
What illicit substance is used commonly in adolescence that can lead to MI and SCD?
Marijuana
What causes MI/SCD with marijuana use?
Hypertension, tachycardia, potentially coronary vasospasm
What illicit substances aren’t used as common as marijuana in adolescents, but have a higher risk of MI and SCD?
Cocaine and stimulants
What causes MI/SCD with cocaine/stimulant use?
- Sympathetic nervous system activation
- Coronary vasoconstriction
- Acute thrombosis
- Direct EP effects
What are patients who get transcatheter pulmonary valves at increased risk for as compared to patients who get a surgical bioproshetic pulmonary valve?
Endocarditis
What component of social history would have an impact on decision regarding valve replacement?
IV drug use- Increased risk for endocarditis
What are two major known risk factors for endocarditis that should be evaluated prior to any type of valve replacement?
- IV drug use
- Poor dental health
What changes are expected on CPET for a patient with reduced ventricular function (peak VO2, HR response, O2 pulse, VAT)?
- Lower than normal % of predicted peak VO2
- Chronotropic incompetence with inadequate or inappropriate HR response to exercise
- Reduced rise in O2 pulse
- VAT lower than predicted
What changes are expected on CPET for a patient with significant AV valve disease (peak VO2, O2 pulse, VAT)?
- Lower than normal % of predicted peak VO2
- Reduced rise in O2 pulse
- VAT lower than predicted
What changes on CPET testing are seen in Fontan patients?
- Low-normal CO and O2 pulse at rest
- Lower exercise-related increases: Lower peak VO2, lower peak HR, decreased or flattened O2 pulse, VAT lower than predicted
Why do Fontan patients have lower exercise-related increases in Vo2, HR, O2 pulse and VAT?
- Lower CO and O2 pulse at rest
- Passive perfusion to pulmonary vasculature can’t accommodate higher HR and CO that is needed during peak exercise
What are some common reasons for pediatric stress testing?
- Evaluate specific signs/symptoms that are induced or aggravated by exercise
- Assess or identify abnormal responses to exercise in children with cardiac, pulmonary or other organ disorders (including the presence of myocardial ischemia and arrhythmias)
- Assess efficacy of specific medical or surgical treatments
- Assess functional capacity for recreational, athletic and vocational activities
- Evaluate prognosis, including both baseline and serial testing measurements
- Establish baseline data for institution of cardiac, pulmonary or MSK rehabilitation
What is CPET often indicated for in pediatric patients?
- Assessment of EP abnormalities (long QT, WPW, suppression of ventricular ectopy, other arrhythmias)
- Safety of participation in sports/exercise capacity
- Efficacy of medical/surgical interventions
What are some circumstances when exercise testing should be terminated?
- Inadequate CO: SBP >250mmHg, DBP >125mmHg, fall in SBP >10mmHg from baseline with increasing workload)
- SpO2 <90% or 10 point drop from baseline
- > 2mm flat or down-sloping ST depression
- SVT
- Increasing ventricular ectopy (>3-beat run)
- Development of a BBB or AV block
- Dyspnea
- Angina suggestive of ischemia
- Patient wants to stop
Increases in HR up to what can be expected on exercise testing?
> 200bpm on treadmill
>195bpm on bike
What variables are typically assessed during CPET with gas anaylsis?
- Peak VO2
- Max HR
- O2 pulse (VO2 per heart beat, mL/beat/kg)
- O2 saturation
- BP
- VAT
- End tidal pO2 and pCO2
- Ve/VCO2 slope
- ECG
What is VAT?
Ventilatory anaerobic threshold: VO2 just before the exercise intensity at which pulmonary ventilatory equivalent for O2 increases disproportionately relative to VO2 marked by onset of anaerobic metabolism and buffering of lactic acid
What is Ve/VCO2 slope used for?
To determine efficiency of gas exchange and potential V/Q mismatch when interpreting in conjunction with end-tidal volumes
What are higher risks for doing exercise stress testing?
- Pulmonary HTN
- LQTS
- DCM/RCM with CHF or arrhythmia
- History of hemodynamically unstable arrhythmia
- HCM with symptoms, >mild LVOTO, documented arrhythmia
- Greater than moderate airway obstruction on baseline PFTs
- Marfan + activity related CP in whom a non-cardiac cause of CP is suspected
- Suspicion of myocardial ischemia with exertion
- Routine testing of Marfan
- Unexplained syncope with exercise
What are some lower risks for doing exercise stress testing?
- Symptoms during exercise in an otherwise health child with normal exam/ECG
- Exercise-induced bronchospasm studies in absence of severe resting airway obstruction
- Asymptomatic ventricular ectopy in patients undergoing evaluation for possible LQTS
- Asymptomatic ventricular ectopy in patients with structurally normal hearts
- Patients with unrepaired or residual congenital cardiac lesions who are asymptomatic at rest (L-R shunts- ASD/VSD/PDA/PAPVR, obstructive right heart lesions w/o severe resting obstruction- TS, PS, ToF, obstructive left heart lesions w/o severe resting obstruction- Cor triatriatum, MS, AS, CoA, regurgitant lesions regardless of severity)
- Routine f/u of asymptomatic patients at risk for myocardia ischemia (Kawasaki w/o giant aneurysms or known coronary stenosis, after repair of anomalous LCA, after arterial switch)
- Routine monitoring in transplant patients not experiencing rejection
- Palliated cardiac lesions w/o uncompensated CHF, arrhythmia or extreme cyanosis
- History of hemodynamically stable SVT
- Stable DCM w/o uncompensated CHF or documented arrhythmia
What variables on exercise testing are most useful in determining aerobic/anaerobic functional capacity?
- VO2
- O2 pulse VAT
What does O2 pulse represent?
Volume of O2 taken up by pulmonary blood with each heart beat
What does O2 pulse depend on?
Volume of O2 extraction by peripheral skeletal muscles
How do you calculated O2 pulse?
Divide VO2 by the simultaneously recorded HR (VO2/HR)
*Re-arrange Fick equation where O2 pulse is product of SV and AVO2 difference…. VO2/HR = SV * C(a-v)O2
Immediate increases in O2 pulse in early phases of exercise depends primarily on increases in what?
SV
As the work rate increases, O2 pulse increases primarily because of increasing what?
C(a-v)O2
*Max O2 extraction occurs in tissues at peak exercise, but mixed venous saturation is constant. Thus, more O2 is extracted from each stroke volume of blood during incrementally increased exercise workload
How do O2 pulse and VO2/heartbeat increase with maximum workload?
Hyperbolic fashion (reflected in an increased HR)
What happens to the O2 pulse if a patients stroke volume is reduced?
-O2 pulse (and C(a-v)O2) reach max values at low work rates
O2 pulse is a surrogate marker for what?
Stroke volume
*Patients with compromised ventricular function and limited stoke volume adaptation will have a reduced rise in O2 pulse or flattened O2 pulse during max exercise
O2 pulse and VO2 are measures of what during exercise?
Aerobic capacity
What are 2 peak exercise parameters?
VO2 and O2 pulse
What is a measure of aerobic fitness obtained at submaximal exercise?
VAT (ventilatory anaerobic threshold)
What is the VAT (ventilatory anaerobic threshold) defined by?
VO2 just before the exercise intensity at which the pulmonary equivalent for O2 (VE/VO2- ratio of ventilation to O2 intake) increases while the ventilatory equivalent for CO2 (VE/VCOR- ratio of ventilation to CO2 output) remains constant
What happens at the VAT?
Acid (lactate) production begins due to reliance of anaerobic metabolism as metabolic demands exceed the cardiovascular system’s ability to deliver O2 to exercising muscles
How is VAT expressed?
As a % of peak VO2
Thus VO2 and VAT usually trend in the same direction…patients with impaired cardiac function typically fail to reach their normal % predicted VO2 and have a VAT lower than predicted
What is the 95% lower limit of VAT for adults and children?
Adults: 40%
Children: 44%
What does a VAT that is below the 40% predicted indicate?
Impairment in ability to CV system to increase CO to support hemodynamic demands of exercise
Any cardiovascular condition that impairs what will lower the VAT?
O2 delivery to exercising muscles
What does VAT assess?
Anaerobic capacity
What changes are seen in terms of O2 consumption, peak O2 pulse and VAT in patients with single-ventricle physiology (Fontan), impaired systemic ventricular function or significant AVVR?
Decreased for all 3
What does VACTERL stand for?
- Vertebral anomalies
- Anal atresia
- Cardiac defects
- TE fistula
- Renal anomalies
- Limb abnormalities (radial/non-radial)
Is VACTERL a syndrome?
No- this is an association… no common pathogenic mechanism for occurrence, but defects occur together much more frequently than by chance alone
How many defects must be present to diagnose someone with VACTERL?
At least 3
*VACTERL is a diagnosis of exclusion, so there shouldn’t be any clinical/lab evidence of an alternate diagnosis
What is thought to cause VACTERL?
Developmental field defect during blastogenesis that results in abnormal embryonic mesoderm derivatives
CHD has been reposted in what % of patients with VACTERL?
40-80%
What is the most common cardiac defect in VACTERL patients?
VSD
*Others seen include ASD, PDA, ToF, DORV, AP window, vascular rings
True or False: A single umbilical artery is frequently seen in patients with VACTERL association?
True- this finding should prompt an evaluation of all organ systems for congenital anomalies
CHARGE syndrome?
- Coloboma of eye
- Heart defects
- Atresia choanae
- Retardation of growth
- Genital abnormalities
- Ear anomalies (hearing loss)
What are the most frequent cardiac defects seen in CHARGE syndrome?
ToF, DORV, aortic arch anomalies
A mutation in what gene is seen in many patients with CHARGE syndrome?
CHD7
What is the most common heart-hand syndrome?
Holt-Oram
Holt-Oram syndrome inheitance?
AD
Holt-Oram syndrome?
- Upper-limb skeletal anomalies of preaxial radial ray (triphalangeal thumb to phocomelia)
- CHD (75% cases): ASD and VSD
- Progressive AV conduction delay
TBX5?
Holt-Oram
Complete or partial agenesis of pectoralis major muscle that is variably associated with other thoracic malformations, upper-limb malformations or both?
Poland sequence
*Not usually associated with CHD
True or False: Intelligence and development is usually normal in VACTERL patients?
True
*Overall prognosis depends on type/severity of defects present
What are important parts of the CV exam for the pre-participation CV screening of competitive athletes?
Resting BP/HR, auscultation, femoral pulses
HTN can be diagnosed if a patient has auscultation-confirmed BP readings of what?
At or above 95th percentile for age, sex, height percentiles (>130/80mmHg in children >13 years) on 3 different visits
What should be performed for confirmation of HTN in children and adolescents before they undergo additional testing?
Ambulatory blood pressure monitoring
*More accurate for diagnosis of HTN than clinical BP measurement, can rule-out white-coat HTN and more reproducible than casual/home BP measurements
List BPs for kids greater than or equal to 13 for normal BP, elevated BP, stage 1 HTN and stage 2 HTN
Normal: <120/<80mmHg
Elevated: 120/<80 to 129/<80mmHg
Stage 1: 130/80-139-89mmHg
Stage 2: >140/90
List BPs for kids under 13 for normal BP, elevated BP, stage 1 HTN and stage 2 HTN
Normal: <90th percentile
Elevated: >90th percentile to <95th percentile or 120/80mmHg to <95th percentile (whichever is lower)
Stage 1: >95th percentile to <95 percentile + 12mmHg, or 130/80 to 139/89mmHg (whichever is lower)
Stage 2: >95th percentile +12mmHg or >140/90mmHg (whichever is lower)
What is the purpose of echo in HTN?
- Cardiac target organ damage
- Rule out secondary causes like CoA
When should echo be performed in HTN?
When pharmacologic treatment of HTN is being considered
What exam findings would point against CoA as a cause of HTN?
- Normal femoral pulses
- No upper/lower gradient
What patients would you exclude from competitive sports participation until BP is better controlled?
- Uncontrolled Stage 2
- Evidence of end-organ injury (echo-evident LVH)
What should be reinforced at every encounter for HTN patients?
Lifestyle measures (diet, sleep, aerobic activity)
What should be done for a BP in the elevated range?
Lifestyle medications
Repeat measurement in 6 months
What lab tests are part of the diagnostic evaluation in all patients with HTN?
Screening UA
Chemistry panel
When should patients with HTN get a renal US?
- Kids <6
- Those with abnormal urinalysis findings or renal function
Fever, knee pain/swelling, heart murmur, MR, elevated CRP?
Acute rheumatic fever
What is a delayed, post-infectious sequela of pharyngitis due to group A B-hemolytic strep?
Acute rheumatic fever
How is acute rheumatic fever diagnosed?
Jones criteria
What test can be done as evidence of a recent group A B-hemolytic strep infection when considering acute rheumatic fever?
Anti-streptolysin O titer
Especially when throat culture or rapid strep test is negative
In what geographic regions does acute rheumatic fever remain a significant source of morbidity in youth?
Asia, Pacific Rim, Africa
The incidence of acute rheumatic fever is highest in children between what ages?
5-15
Where is acute rheumatic fever commonly seen?
Populations where strep pharyngitis isn’t commonly treated
What is the major cardiac manifestation of acute rheumatic fever?
Carditis
*Present in more than 1/2 of all initial episodes
What is the most common form of carditis seen in acute rheumatic fever?
Valvulitis- Often new-onset MR
*But aortic valve can also be affected
True or False: Subclinical carditis (echo with MR/AR or both) is sufficient in the diagnostic criteria for acute rheumatic fever?
True- may or may no have murmur
What are other forms of carditis that can occur in acute rheumatic fever besides valvulitis?
- CHF due to myocarditis
- Prolonged PR interval
- Pericardial effusion
- Any combination
Besides the heart, what are the other organ systems affected?
Joins, skin and CNS
What is the classical MSK presentation of acute rheumatic fever?
Migratory polyarthritis of larger joints
- Now monoarticular arthritis qualifies as major criteria in areas where there is mod-high risk for ARF
- Severity can also range from marked arthritis to milder arthralgia
What are the 2 main skin manifestations of acute rheumatic fever?
- Subcutaneous nodules
- Erythema marginatum
- Much less common than carditis/joint involvement
- Very specific for acute rheumatic fever
What is the major neurological abnormality seen in acute rheumatic fever?
Sydenham chorea
What gender is Sydenham chorea with acute rheumatic fever more common in ?
Females
When does Sydenham chorea typically develop in acute rheumatic fever?
After other manifestations have resolved
What is on the differential diagnosis for acute rheumatic fever?
- Septic arthritis
- Juvenile rheumatoid arthritis
- Chikungunya disease
- Lyme disease
- Kawasaki disease
- Viral myocarditis
- Infective endocarditis
- HSP
- SLE
- Sickle cell disease
- Gout
- Leukemia
- Lymphoma
What is included in the treatment of acute rheumatic fever?
- PO or IM benzathine PCN
- Supportive care for carditis
- NSAIDS for fever/joint symptoms
- Bed rest for mod-severe carditis (not based on evidence based data)
True or False: Cardiac surgery during an acute episode of acute rheumatic fever isn’t indicated unless there is uncontrolled heart failure?
True
What is used for long-term prophylaxis in acute rheumatic fever?
-IM PCN every 3-4 weeks through at least age 21 or 10 years after initial episode (longer if patient lives in setting where endemic or with residual heart disease)
True or False: The revised Jones criteria include monoarticular arthritis if the patient is from an area of mod-high risk of developing acute rheumatic fever
True
True or False: Echo can be used to diagnose carditis in acute rheumatic fever, even if auscultation doesn’t reveal a new-onset heart murmur?
True
Absent pulmonary valve syndrome is most commonly associated with what?
ToF
*Occurs in 2.5% of ToF
True or False: Surgery is often elective in absent pulmonary valve?
True- unless patient has respiratory distress or needs mechanical ventilation
What are some methods for pulmonary artery plication in absent pulmonary valve syndrome?
- Valved conduit
- Monocusp valve placement
- Transannular patch + reconstruction of RVOT
*No single method of RVOT reconstruction has been proven to be superior
What are some known risk factors rehospitalization, re-operation and death in ToF absent PV?
- Era of operation
- Prematurity
- Lower weight at operation
- Neonatal repair
- Longer CPB
- Pre-op respiratory distress
Patients with ToF-PA who have pre-operative respiratory distress more commonly have what lung pathology?
Bronchomalacia- Leads to recurrent respiratory disease/hospitalizations (especially up to age 5)
*Increased mortality for patients with pre-op respiratory distress
What rhythm disturbance is common in sleep, especially in younger patients?
Bradyarrhythmia- sinus bradycardia, junctional escape, sinus pauses, send-degree (type 1) AV block
What often causes bradyarrhythmia during sleep?
Vagal
True or False: Most bradyarrhythmia during sleep doesn’t require treatment?
True- most are asymptomatic and do not need treatment
What patients experience bradyarrhythmias during sleep with increased frequency?
Sleep apnea (especially during periods of apnea)
What should be done for a patient with elevated BMI, daytime fatigue, trisomy 21 and vagally mediated pauses during sleep?
Sleep study
True sinus node dysfunction is common after what types of surgery for CHD?
- Fontan
- Atrial switch
- Sinus venosus defect repair
*Seen less frequency after surgery for other types f CHD
What are some possible symptoms seen with sinus node dysfunction?
- Dizziness
- Syncope
- Presyncope
- Altered consciousness
- Chronotropic incompetence
- Exercise intolerance
If necessary, what is the treatment of sinus node dysfunction?
Pacemaker
When is a pacemaker indicated for sinus node dysfunction?
Symptomatic bradycardia- syncope, presyncope confusion thought to be related to cerebral hypoperfusion or chronotropic incompetence
*Fatigue is very non-specific and often multifactorial as a symptom of bradycardia
What are the IIa recommendations for pediatric patients to get a pacemaker in the setting of sinus node dysfunction?
Resting HR <40bpm or pauses greater than 3 seconds (in complex CHD)
What are the IIb recommendations for pediatric patients to get a pacemaker in the setting of sinus node dysfunction?
Resting HR <40bpm or pauses greater than 3 seconds (in biventricular repair of heart disease)
What treatment may improve sleep-related bradyarrhythmia if indicated?
Treatment of sleep apnea
True or False: Patients with sleep-related sinus bradycardia or transient sinus pauses occurring during sleep, permanent pacing shouldn’t be performed unless other indications for pacing are present?
True
An EP study for what can sometimes be helpful to assess sinus node function in a symptomatic patient whose symptoms are difficult to correlate with forms of sinus node dysfunction?
Sinus node recovery time
In the workup of sinus node dysfunction, how can an exercise stress test be helpful?
It can determine chronotropic incompetence
How is flow in pulmonary vasculature impacted in a fetus with HLHS?
- Entire CO goes across MPA
- Quantity of blood flow in pulmonary vasculature likely higher than normal
- Pulmonary venous flow higher than normal
In a fetus with HLHS, what is the path of blood flow that is returning from the pulmonary veins?
-Has to cross the atrial septum from left to right to get to RV, then MPA across ductal arch to body
What is very important in a fetus with HLHS in terms of the path of blood flow?
Having an unrestricted atrial septal communication to allow for decompression of the LA
What happens to a fetus with HLHS and a restrictive atrial septum?
- LA pressure is high (blood can’t get from LA across atrial septum to RA)
- Causes pulmonary venous pressure to be high
- Results in microvascular changes to the pulmonary veins
- Results in the PVR remaining high after birth
- Results in hypoxia and inadequate tissue oxygenation… increase risk of neonatal demise
Neonates with HLHS and what other finding have a particularly poor prognosis?
Restrictive or intact atrial septum
What impact does maternal hyperoxygenation have on a fetus?
- Increased maternal O2 delivery to fetus
- Prompts drop in fetal PVR
How does a lower fetal PVR impact the venous return to the fetal left heart?
Increases it… lower PVR augments pulmonary arterial flow and thus venous return to fetal left heart
What is used as a diagnostic and predictive tool in the assessment of fetuses with HLHS?
Maternal hyperoxygenation… used to identify fetuses with pulmonary vascular beds that aren’t reactive
An infant with HLHS and restrictive atrial septum needs what after birth?
Prompt decompression of atrial septum
*Infants are at high risk of demise after delivery
When using maternal hyperoxygenation in fetuses with HLHS, what is being assessed?
PI in the pulmonary artery via fetal echo
*Used as a means of assessing pulmonary vasoreactivity… then can infer presence of microvascular changes in the pulmonary bed
What is seen on echo during maternal hyperoxygenation testing in fetuses with HLHS and restrictive atrial septa v. normal fetuses and those with HLHS and patent atrial septa?
- No significant change in pulmonary artery PI
- Normal fetuses and those with HLHS/patent atrial septum had alteration in the pulmonary artery PI during maternal hyperoxygenation
What can maternal hyperoxygenation testing in fetuses with HLHS be used to predict?
Need for immediate intervention on the interatrial septum
What are the 3 identifiable waves on Doppler of the pulmonary veins?
- S
- D
- A
What changes are seen in the S/D/A waves of a pulmonary vein in a fetus with HLHS and restrictive atrial septum?
- Accelerated flow during systole (S-wave)
- Accelerated flow during diastole (D-wave)
- Reduced or reversed flow at the time of atrial contractions (A-wave)
What happens to the A-wave on a pulmonary vein doppler in the setting of elevated LA pressure?
A-wave reverses
*Larger A wave reversals indicate more elevated LA pressure (i.e. in a fetus with HLHS and restrictive atrial septum)
Should NO or 100% FiO2 be given to a neonate with HLHS and restrictive atrial septum?
No… would lower PVR and increased pulmonary venous return to LA, but restriction in atrial septum, this will only worsen LA hypertension
What effect does maternal hyperoxygenation normally have on a fetus?
- Increased maternal O2 delivery to the fetus
- Lower fetal PVR
What can be used to assess fetal pulmonary vasoreactivity?
Maternal hyperoxygenation
What happens to the peripheral SVR and CO in septic shock?
Peripheral SVR low
CO high
What results in lactic acidosis in the setting of septic shock?
Impaired O2 extraction in the setting of low SVR, high CO
What is the mixed venous saturation in septic shock?
High- issue is impaired O2 extraction
What type of shock (warm/cold) is seen with poor capillary refill, higher filling pressures, normal/narrow pulse pressure, low mixed venous saturation?
Cold
What is NIRS monitoring helpful for?
- Estimating O2 delivery to various tissue beds
- Noninvasive corollary to invasive diagnostic modalities that monitor CO (mixed venous saturation, thermodilution, etc)
True or False: The absolute value of a NIRS monitor may not always be accurate, but the trend can reflect changes in mixed venous saturation?
True… Trending device
What can falsely lower NIRS monitor readings?
- Jaundice
- Poor skin perfusion
- Malpositioned probes
Why does jaundice cause the NIRS valve to be falsely low?
Bilirubin molecules deposited in the skin can absorb light at a wavelength similar to that emitted by most commercially available NIRS devices (700-850nm)
What could be a potential cause of a significant low saturation on a blood gas?
If the catheter tip was in the coronary sinus
*CS blood has lowest O2 content of any vascular bed due to high O2 extraction in the myocardium
What can air bubbles as a contaminant in a blood gas sample cause?
- Partial pressure of O2 to be falsely high
- Partial pressure of CO2 to be falsely low
What type of shock results in the peripheral SVR being low, CO being high, O2 extraction impaired, lactic acidosis and high mixed venous saturation?
Septic
In what circumstances will patients demonstrate signs of cold shock- poor capillary refill, elevated filling pressures, narrow pulse pressure, low mixed venous saturation?
Low CO state/cardiogenic shock
What is a non-surgical alternative for eligible patients with significant pulmonary regurgitation who require pulmonary valve replacement?
Percutaneous pulmonary valve implantation
What are some complication of percutaneous pulmonary valve implantation?
- Coronary artery compression
- Conduit tear or disruption
- Infective endocarditis
- Stent fracture
True or False: Percutaneous pulmonary valve implantation involves manipulation of the RV infundibulum?
True
In a percutaneous pulmonary valve implantation, the stent placed to ensure a safe landing zone for the valve can protrude into the RVOT… what effect can this have?
-Mechanical irritation and local trauma of the RVOT which may trigger VT
What % of patients experience percutaneous pulmonary valve implantation related VT within 24 hours of implantation?
7.5%
Describe the VT seen in patients following percutaneous pulmonary valve implantation?
- Nonsustained
- Monomorphic
- Rates 120-170
- QRS axis suggests an RVOT origin
Which patients appear to have a greater frequency of percutaneous pulmonary valve implant related VT?
Younger/smaller… may be related to shorter outflow tracts becoming more irritated from the stent
What is the first-line therapy for VT from any cause?
Beta blockers
