What characterizes the murmur associated with mitral stenosis?

In mitral stenosis, the murmur is characterized by a diastolic, mid to late, low-pitched sound that is often preceded by an opening snap. This specific timing in the cardiac cycle occurs during diastole when the left atrium contracts to push blood through the narrowed mitral valve into the left ventricle.

The nature of the murmur is low-pitched due to the turbulence created by the obstruction of blood flow through the stenosed valve. The opening snap is an important feature; it occurs when the stenotic valve opens and is produced by the sudden halt of the mitral leaflets from a tightly closed position, contributing to the sound heard upon auscultation.

This characteristic murmur is important in diagnosing mitral stenosis and helps differentiate it from other valve pathologies. The opening snap and the low-pitched diastolic murmur reflect the increased pressure in the left atrium and the gradient that occurs as blood flows through the narrowed mitral valve during diastole.