Opening Snap

The opening snap is a high-pitched sound in early diastole that occurs in the vast majority of patients with mitral stenosis. It coincides with the opening of the mitral valve. It generally occurs closer to S2 than the pericardial knock and the S3 gallop. It is best heard in the “supramammary area” – just above and slightly to the left of the nipple (or between the apex and the left sternal border).

 

Patient 1:

This is a young woman who grew up in Mexico and presented with a transient ischemic attack, severe flank pain from a renal embolism, and hemoptysis. She was found to have severe mitral stenosis. Note the loud S1 and opening snap.

This patient also has a rumbling diastolic murmur with presystolic accentuation when listening over the apex.

Opening Snap

Annotated

Patient 2:

This is an older woman from Romania with severe mitral stenosis from rheumatic heart disease.

Opening Snap

Annotated