A 26-year-old man collapsed while playing basketball and could not be resuscitated. Prior to the episode, he had exertional dyspnea and lightheadedness. Autopsy is performed. The lungs are completely normal. The heart is shown in the exhibit.

If the patient had been examined prior to death, which of the following would most likely have been present?

Question

A 26-year-old man collapsed while playing basketball and could not be resuscitated. Prior to the episode, he had exertional dyspnea and lightheadedness. Autopsy is performed. The lungs are completely normal. The heart is shown in the exhibit.

If the patient had been examined prior to death, which of the following would most likely have been present?

Quizplus · Accepted Answer

11ec160b_3c96_317e_9249_d938b0ff21bb_MD0001_00 Gross examination of this patient's heart reveals asymmetric left ventricular hypertrophy (LVH) (ie, wall thickening) that is most prominent in the interventricular septum, which is characteristic of hypertrophic cardiomyopathy (HCM). HCM results from genetic mutations that affect cardiac sarcomere proteins; the phenotypic manifestations of the disease typically begin during adolescence and involve myocardial disarray and left ventricular (LV) thickening that mostly affects the interventricular septum. The septal thickening commonly leads to dynamic LV outflow tract obstruction that causes a mid-systolic murmur and reduces cardiac output, often leading to exertional symptoms (eg, dyspnea, angina, lightheadedness, syncope). Sudden cardiac death (SCD) can also occur. In addition to obstructing cardiac output, the LVH in HCM also frequently impairs LV diastolic filling, with an S4 commonly heard as blood strikes the thick, stiffened LV wall. (Choices A and E) A weak and delayed carotid upstroke (ie, pulsus parvus et tardus) as well as a soft and single S2 (caused by delay of aortic valve closure to the point that it occurs simultaneously with pulmonic valve closure) are characteristic of aortic stenosis (AS). Severe AS commonly causes exertional symptoms (eg, dyspnea, lightheadedness) and can cause SCD, but it usually results from age-related calcification and affects older patients (eg, age >40 for a bicuspid aortic valve or older for a congenitally normal valve). Concentric LVH can develop with severe AS; the wall thickening is evenly distributed and does not favor the interventricular septum as it does in HCM. (Choices B and C) An early systolic murmur at the cardiac apex is consistent with mitral regurgitation (MR), and a mid-diastolic murmur at the cardiac apex is classic for mitral stenosis (MS). Both MR and MS commonly present with heart failure symptoms (eg, dyspnea, orthopnea, peripheral edema), and SCD is relatively uncommon. In addition, asymmetric LVH affecting the interventricular septum does not occur (eccentric LVH can develop with severe MR, and no LVH develops with MS as the left ventricle does not undergo pressure or volume overload). Educational objective: Hypertrophic cardiomyopathy typically involves asymmetric left ventricular hypertrophy (LVH) that is most prominent in the interventricular septum and commonly causes left ventricular (LV) outflow tract obstruction. The LVH also impairs diastolic LV filling, with an S4 commonly heard as blood strikes the thick, stiffened LV wall.

A 26-Year-Old Man Collapsed While Playing Basketball and Could Not