How might abnormal sounds be used to diagnose heart problem?

Answer 1

To understand what abnormal sounds mean you first must know what healthy sounds are. Two distinct sounds can be heard during each cardiac cycle. These heart sounds are commonly described by the monosyllables "lub" and "dup"; and the sequence is designate lub-dup, pauce, lub-dup, pause, etc.... The first heart sound (lub) is referred to as S1 and is associated with closure of the AV valves at the beginning of the ventricular systole (constriction). The second hear sound (dup), called S2, occurs as the semilunar valves close and corresponds with the end of the systole.

Abnormal hear sounds are called murmurs and often indicate valvular problems. In valves that do not close tightly, closure is followed by a swishing sound due to the backflow of blood (regurgitation). Distinct sounds, often described as high-pitched screeching, are associated with tortuous flow of blood through constricted, or stenosed valves.

Answer 2

The valves of the heart make specific sounds when operating normally and abnormally. By knowing the difference in sounds, one can determine the defect. For example, a normal heart makes a lub-dub sound upon each beat. The sound you hear is that of the valves opening and closing. If you hear a lub-swish-dub, there is a valve defect and blood is back flowing when the heart muscle compresses because the valve is not fully closed at the time of contraction.