What condition presents with a mid-systolic click best heard at the apex?

Mitral valve prolapse is characterized by the presence of a mid-systolic click, which is best appreciated at the apex during auscultation. This click results from the sudden tensing of the mitral valve leaflets and chordae tendineae as the valve leaflets bulge back into the left atrium due to inadequate support or elongation.

In mitral valve prolapse, this abnormal movement often leads to a late systolic murmur if mitral regurgitation is also present, but the mid-systolic click is a hallmark feature of the condition on its own. Recognizing this click is crucial for diagnosis and differentiating it from other cardiac conditions.

Other options are associated with different auscultatory findings. For example, mitral regurgitation typically produces a holosystolic murmur rather than a click. Tricuspid regurgitation generally generates a blowing murmur best heard along the left sternal border, and cardiac tamponade presents with features such as muffled heart sounds rather than specific clicks or murmurs. Understanding these distinctions helps in accurately diagnosing cardiac conditions.