Diastolic Murmurs - Mitral Stenosis

     You are listening to a typical example of the murmur produced by mitral valve stenosis. As opposed to aortic regurgitation, mitral stenosis has a female preponderance, with the female:male ratio being about 2:1. Almost all cases of mitral stenosis are rheumatic in origin, although congenital causes can occur.

     The murmur of mitral stenosis is best heard at the apex with little radiation. It is nearly holodiastolic with pre-systolic accentuation due to the atrial kick. It is usually described as low-pitched, decrescendo, and rumbling, and can be heard best with the patient in the left lateral decubitus position. The murmur appears about 0.08 seconds after S2, and is heralded by an “opening snap”. This is a brief, loud sound which is caused as the stenotic valve suddenly halts its normal opening at the start of diastole.