S1 and S2 are the normal heart sounds you hear when the heart valves close. Heart murmurs are extra sounds that can be heard during systole, diastole, or as a continuous sound. S3 and S4 are abnormal ...

An aortic stenosis murmur is an unusual sound the heart makes due to a narrowing of the aortic heart valve. The narrowed heart valve restricts blood flow from the heart, which can create a murmur.