A 64-year-old man dies suddenly while playing tennis. In the preceding months, he experienced fatigue and some exertional dyspnea. Autopsy is performed. The heart examination shows left ventricular septal thickness of 1.6 cm (normal:

Question

A 64-year-old man dies suddenly while playing tennis.  In the preceding months, he experienced fatigue and some exertional dyspnea.  Autopsy is performed.  The heart examination shows left ventricular septal thickness of 1.6 cm (normal: <1.1), posterior wall thickness of 1.6 cm (normal: <1.1), and an internal left ventricular diameter of 3.2 cm (normal: 3.5-5.9).  No focal myocardial scarring is seen.  Which of the following is the most likely cause of the cardiac findings seen in this individual?

Quizplus · Accepted Answer

11ec160b_38bc_7956_9249_aff852af0078_MD0001_00 This individual's autopsy reveals thickened left ventricular walls and a small left ventricular cavity consistent with concentric hypertrophy.xa0 Concentric hypertrophy results from the addition of myocardial contractile fibers in parallel in response to chronic pressure overload.xa0 The adaptation allows for increased contractile force but causes impaired diastolic filling and can lead to heart failure with preserved ejection fraction (diastolic failure).xa0 Common causes of concentric hypertrophy include prolonged systemic hypertension and aortic stenosis. Patients with severe aortic stenosis typically experience exertional symptoms, including fatigue, shortness of breath, angina, and presyncope or syncope.xa0 Sudden cardiac death can result from the inability to increase cardiac output with exertion due to left ventricular outflow obstruction. (Choice B)xa0 Dilated cardiomyopathy results from a primary insult to cardiomyocytes (eg, viral infection, chemical toxicity, inherited disease) that causes myocardial contractile dysfunction, left ventricular volume overload, and eventual eccentric hypertrophy. (Choice C)xa0 Severe mitral regurgitation causes left ventricular volume overload and eccentric hypertrophy. (Choice D)xa0 Obstructive coronary artery disease can lead to eccentric hypertrophy via myocardial contractile dysfunction and consequent left ventricular volume overload (ie, ischemic heart disease).xa0 The development of concentric hypertrophy is not typical. (Choice E)xa0 Rheumatic mitral stenosis causes impaired diastolic filling of the left ventricle.xa0 It does not increase the pressure or volume load on the left ventricle and does not cause ventricular hypertrophy. Educational objective: Concentric left ventricular hypertrophy involves thickening of the ventricular walls and reduction in the ventricular cavity size.xa0 It occurs via the addition of myocardial contractile fibers in parallel in response to chronic pressure overload.xa0 Aortic stenosis and prolonged systemic hypertension are common causes of concentric left ventricular hypertrophy.

A 64-Year-Old Man Dies Suddenly While Playing Tennis