Which heart sound is associated with mitral valve closure?

The sound associated with mitral valve closure is known as the first heart sound, or S1. This sound occurs when the ventricles contract, and the mitral and tricuspid valves close to prevent the backflow of blood into the atria. Specifically, the closure of the mitral valve precedes that of the tricuspid valve, producing the distinctive sound of S1.

During the cardiac cycle, S1 represents the beginning of ventricular systole, where the pressure in the ventricles rises, leading to the closing of these AV (atrioventricular) valves. Understanding S1 is crucial for interpreting heart sounds during auscultation and can provide insights into the heart's mechanical function and valvular integrity.

The other heart sounds, S2, S3, and S4, represent different phases in the cardiac cycle. S2 is associated with the closure of the aortic and pulmonary valves at the end of ventricular systole, while S3 and S4 relate to diastolic events and are not directly linked to mitral valve closure.