You are examining a 65-year-old male from Central America with a history of rheumatic valvular disease. Which one of the following is the principal auscultatory finding of aortic regurgitation?
A) An S3 gallop heard best at the cardiac apex with the patient supine
B) A triphasic pericardial friction rub with the patient seated and leaning forward
C) A low-pitched decrescendo diastolic murmur that is loudest at the lower left sternal border with the patient seated and leaning forward
D) A high-pitched crescendo/decrescendo midsystolic murmur that is loudest at the right upper sternal border and radiates to the carotid arteries with the patient sitting upright
E) A harsh holosystolic murmur that is loudest at the lower left sternal border and radiates to the left lateral chest wall with the patient in the left lateral decubitus position
Aortic regurgitation in an older adult may be due to a congenital bicuspid aortic valve, which often is accompanied by aortic stenosis. Rheumatic aortic valvular disease may also cause aortic regurgitation, which is the most common cause in the developing world but less common in the United States.
The hallmark murmur of aortic regurgitation in either case is a “blowing” decrescendo diastolic murmur along the tract from the aortic valve (upper right sternal border) down to the lower left sternal border, where it is loudest. It is best heard with the patient sitting, leaning forward, and holding his or her breath in expiration.
Both bicuspid aortic valve and rheumatic valve disease may also be associated with aortic stenosis. The typical murmur of aortic stenosis is a mid- to long crescendo/decrescendo systolic murmur, loudest at the right upper sternal border, and often radiating to the carotid arteries. An S3 gallop may also be present in decompensating aortic regurgitation, due to the associated left ventricular dilatation, but this is a secondary finding in later stages.
A harsh holosystolic murmur at the lower left sternal border radiating to the axilla is characteristic of mitral valve regurgitation, another potential condition found in rheumatic valvular disease. A pericardial friction rub is the principal auscultatory finding in acute pericarditis.
Ref: Jameson JL, Fauci AS, Kasper DL, et al (eds): Harrison’s Principles of Internal Medicine, ed 20. McGraw-Hill, 2018, pp240-248.