A31-year-old woman with no significant medical history presents for a routine physical examination. Vital signs include blood pressure 118/78 mm Hg, pulse 70 per minute, respiratory rate 16 per minute, and temperature 98.8°F. Physical examination reveals a soft late systolic murmur and midsystolic click on cardiac auscultation. The remaining examination is unremarkable, and ECG and laboratory results are all within normal limits. Which of the following is the most likely explanation for the abnormal cardiac finding?
(A) congenital bicuspid valve leading to aortic stenosis
(B) congenital collagen defect leading to tricuspid prolapse
© infective aortic endocarditis leading to aortic regurgitation
(D) myxomatous valvular degeneration leading to mitral prolapse
(E) previous subclinical episode of rheumatic fever leading to mitral stenosis
(F) progressive pulmonary hypertension leading to tricuspid regurgitation
Explanation:
(D) A late systolic murmur with a midsystolic click is the typical auscultatory finding in mitral valve prolapse. This condition is the most frequently occurring valvular lesion and results from a myxomatous change in the mitral valve that, in the vast majority of affected individuals (mostly women), remains asymptomatic. Aortic
stenosis (choice A) produces a “crescendodecrescendo” systolic murmur following an ejection click. The signs and symptoms of tricuspid prolapse (choice B) are similar to those of mitral valve prolapse but tricuspid prolapse is a very unusual finding; it may occur in association with Ebstein anomaly. Aortic regurgitation (choice C) typically produces a high-pitched blowing decrescendo diastolic murmur. Mitral stenosis (choice E) produces an opening snap followed by a late diastolic murmur. Tricuspid regurgitation (choice E) produces a holosystolic murmur and is most commonly due to right ventricular dilation in right heart failure.