Cardiomyopathy Questions - Set 1¶
Question 1¶
A 6-month-old presents with tachypnea and hepatomegaly. Echo shows severely dilated LV with EF 20%. CPK is 10x normal. What is the most likely diagnosis?
A) Viral myocarditis B) Barth syndrome C) Familial dilated cardiomyopathy D) Anomalous left coronary artery from pulmonary artery (ALCAPA) E) Anthracycline cardiomyopathy
Answer
**Correct Answer: D** **ALCAPA**: - Presents at 2-6 months as pulmonary pressures drop - LV dilation, poor function - Elevated CPK (ischemia) - MR from papillary muscle infarction - ECG may show lateral Q waves **Board Pearl:** Infant DCM + elevated CPK = think ALCAPAQuestion 2¶
What is the inheritance pattern of most cases of hypertrophic cardiomyopathy?
A) X-linked recessive B) Autosomal recessive C) Autosomal dominant D) Mitochondrial E) Sporadic only
Answer
**Correct Answer: C** HCM is **autosomal dominant**: - Sarcomere gene mutations - 50% risk to offspring - Variable penetrance and expressivity - MYH7 and MYBPC3 most common **Board Pearl:** HCM = autosomal dominant; 50% risk to first-degree relativesQuestion 3¶
A 15-year-old with HCM has an ICD placed. One year later, he receives an appropriate shock for VT. What is the next management step?
A) Explant ICD as therapy successful B) No change - continue current management C) Add beta-blocker or increase dose D) Cardiac transplant evaluation E) Septal myectomy
Answer
**Correct Answer: C** After appropriate ICD therapy: - Optimize medical therapy (beta-blocker dose) - Address modifiable risk factors - Consider additional medications (amiodarone) - ICD programming review - Myectomy if obstruction contributing **Board Pearl:** Post-ICD shock: optimize beta-blocker, reassess modifiable factorsQuestion 4¶
Which cardiomyopathy has the highest risk of sudden death in pediatrics?
A) Dilated cardiomyopathy B) Hypertrophic cardiomyopathy C) Restrictive cardiomyopathy D) Left ventricular non-compaction E) Arrhythmogenic right ventricular cardiomyopathy
Answer
**Correct Answer: C** **Restrictive cardiomyopathy** has highest SCD risk in children: - Often need transplant within 2-3 years of diagnosis - Very limited medical therapy options - SCD risk from arrhythmias and pulmonary hypertension - Exercise restriction mandatory **Board Pearl:** Pediatric RCM = highest SCD risk; often need early transplantQuestion 5¶
A 12-year-old male has dilated cardiomyopathy with severe LV dysfunction. Skeletal muscle biopsy shows abnormal dystrophin. What is the diagnosis?
A) Duchenne muscular dystrophy B) Becker muscular dystrophy C) Limb-girdle muscular dystrophy D) Emery-Dreifuss muscular dystrophy E) Myotonic dystrophy
Answer
**Correct Answer: B** **Becker muscular dystrophy**: - Dystrophin reduced (vs absent in DMD) - Milder skeletal muscle disease than DMD - Cardiomyopathy can be presenting feature - May survive to adulthood with wheelchair use DMD would have more severe skeletal involvement and absent dystrophin. **Board Pearl:** Becker = reduced dystrophin; DCM may be presenting featureQuestion 6¶
What medication class is contraindicated in patients with obstructive HCM?
A) Beta-blockers B) Calcium channel blockers C) Disopyramide D) Diuretics/vasodilators E) Amiodarone
Answer
**Correct Answer: D** **Vasodilators/diuretics** worsen obstruction in HCM: - Decrease preload → worse obstruction - Decrease afterload → worse obstruction - ACE inhibitors, ARBs, nitrates problematic - Aggressive diuresis contraindicated **Board Pearl:** Obstructive HCM: avoid vasodilators, diuretics, digoxinQuestion 7¶
What echocardiographic finding suggests Pompe disease in an infant with cardiomyopathy?
A) Apical hypertrophy only B) Massive, concentric biventricular hypertrophy C) Regional wall motion abnormalities D) Pericardial effusion E) LV dilatation with poor function
Answer
**Correct Answer: B** **Pompe disease** (glycogen storage disease type II): - Massive concentric hypertrophy (RV + LV) - Short PR interval on ECG - Hypotonia - Low acid alpha-glucosidase level - ERT available if diagnosed early **Board Pearl:** Massive biventricular hypertrophy + hypotonia = Pompe diseaseQuestion 8¶
A child with ARVC has recurrent VT from the RV. What is the typical ECG pattern of VT in ARVC?
A) Right bundle branch block morphology B) Left bundle branch block morphology C) Narrow complex D) Polymorphic E) Irregular RR intervals
Answer
**Correct Answer: B** ARVC VT = **LBBB morphology**: - VT originates from RV - LBBB pattern means activation starts in RV - Superior axis if from RVOT - Inferior axis if from RV apex/base **Board Pearl:** ARVC VT = LBBB morphology (originates from RV)Question 9¶
Which gene mutation accounts for the majority of ARVC cases?
A) MYH7 B) PKP2 (plakophilin-2) C) LMNA D) TTN E) SCN5A
Answer
**Correct Answer: B** **PKP2** (desmosomal gene) most common in ARVC: - 25-40% of ARVC cases - Desmosomal dysfunction → fibrofatty replacement - Other genes: DSG2, DSP, DSC2 - Autosomal dominant with variable penetrance **Board Pearl:** ARVC = desmosomal gene mutations; PKP2 most commonQuestion 10¶
A 4-year-old presents with heart failure. Echo shows thickened RV and LV walls with small cavities, dilated atria, and restrictive filling. What is the most appropriate next test?
A) Cardiac MRI B) Endomyocardial biopsy C) Cardiac catheterization D) Genetic testing E) Exercise stress test