Heart Sounds

Question 1

Wide, fixed split S2

Answer 1

ASD or VSD. S2 split does not vary with inspiration because of the left-to-right shunting.

Question 2

Wide, loud split S1 (+/- diastolic third heart sound).

Answer 2

Cardiac myxoma. Most common cardiac tumor in adults, usually in left atrium. Split S1 is because myxoma delays valve closing. Diastolic third heart sound is tumor “plopping” in the atrium.

Question 3

Hypertrophic cardiomyopathy: murmur and ECG changes? Tx?

Answer 3

Murmur: harsh crescendo-decrescendo along left sternal border. ECG: deep S-wave in V1, high voltage R in V5-6. Tx: beta-blockers (protect against MI [O2], arrhythmia, +diastolic filling time) and non-DHP Ca++ (improve diastolic relaxation, no effect on afterload).

Question 4

Neonatal absent S2 split, cyanosis. Associated with?

Answer 4

Persistent Truncus Arteriosus. Can be associated with DiGeorge syndrome, which is an abnormality of the 3rd and 4th pharyngeal pouches and arches: cleft palat, thymic aplasia, parathyroid abnormality. 22q11 deletion.