A 71-year-old man comes to the office due to a 2-month history of progressive exertional dyspnea. The patient is unable to walk half a block without resting and can no longer climb stairs without stopping every few steps. He also has had difficulty sleeping due to repeatedly waking up at night feeling like he is suffocating. Physical examination shows bilateral lower extremity edema and distended neck veins. Cardiac auscultation findings over the apex are given below. This patient's auscultatory findings most likely reflect which of the following?

Question

A 71-year-old man comes to the office due to a 2-month history of progressive exertional dyspnea.  The patient is unable to walk half a block without resting and can no longer climb stairs without stopping every few steps.  He also has had difficulty sleeping due to repeatedly waking up at night feeling like he is suffocating.  Physical examination shows bilateral lower extremity edema and distended neck veins.  Cardiac auscultation findings over the apex are given below.  This patient's auscultatory findings most likely reflect which of the following?

Quizplus · Accepted Answer

11ec160b_3a84_b6a4_9249_09ffc72da8a6_MD0001_00 Cardiac auscultation in this patient reveals a low-frequency sound occurring just after S2, known as an S3. Although an S3 can be normal in young individuals and pregnant patients, in those age >40 it is typically a sign of left ventricular (LV) volume overload or failure (causing exertional dyspnea and paroxysmal nocturnal dyspnea in this patient). In early diastole, the ventricles relax and the atrioventricular valves open, allowing blood to rush in and fill the ventricles. An S3 is thought to represent reverberant sound created by blood entering an enlarged and overfilled ventricular cavity during rapid passive filling. As a result, S3 is typically heard in pathologic settings causing high ventricular filling pressures and volume overload, particularly aortic or mitral regurgitation and heart failure with reduced ejection fraction (eg, dilated cardiomyopathy). (Choice A) Aortic valve sclerosis may produce a midsystolic ejection murmur but would not produce an extra heart sound. Progression to severe aortic stenosis may eventually produce an S4 due to concentric LV hypertrophy and stiffening of the ventricular wall. (Choice B) Cardiac tamponade causes the restricted right ventricle to bulge into the left ventricle during inspiration. This phenomenon does not generate an auscultatory sound but does cause a >10 mm Hg decrease in systolic blood pressure during inspiration (pulsus paradoxus). (Choice C) Hypertrophic cardiomyopathy can cause dynamic LV outflow obstruction, producing a crescendo-decrescendo ejection systolic murmur. The outflow obstruction can also cause systolic anterior motion of the mitral valve, resulting in mitral regurgitation (holosystolic murmur). (Choice D) Elevated pulmonary arterial pressure (pulmonary hypertension) can present with exertional dyspnea and fatigue and eventual right ventricular failure (elevated jugular venous pressure, peripheral edema). However, auscultation reveals increased intensity of the pulmonic closure sound (P2), and affected patients typically lack nocturnal dyspnea due to intact LV function. Educational objective: An S3 is a low-frequency sound that occurs just after S2 and is typically associated with ventricular volume overload. It is commonly heard in patients with mitral or aortic regurgitation or heart failure with reduced ejection fraction (eg, dilated cardiomyopathy).

A 71-Year-Old Man Comes to the Office Due to a 2-Month