A diastolic decrescendo murmur best heard at the left sternal border is most consistent with which lesion?

Study for the PANCE Cardiology Test. Enhance your knowledge with comprehensive flashcards and multiple-choice questions. Each question comes with hints and detailed explanations. Prepare thoroughly for your exam!

A diastolic decrescendo murmur heard best along the left sternal border points toward regurgitation through a semilunar valve during diastole. This pattern is most classic for aortic regurgitation, where blood leaks back from the aorta into the left ventricle in early diastole. The velocity and pressure gradient are highest right after S2 and then diminish as diastole progresses, creating the decrescendo, blowing quality. Clinically, you’d often hear it best when the patient leans forward and exhales, and it may be accentuated by maneuvers that increase systemic resistance.

In contrast, mitral stenosis produces a diastolic rumble at the apex with a prominent opening snap, not a diastolic decrescendo at the left sternal border. Tricuspid stenosis also gives a diastolic rumble, typically best at the left lower sternal border. Pulmonic regurgitation can produce a diastolic decrescendo murmur at the left upper sternal border, but the classic, most fitting finding for this description is aortic regurgitation.