Which murmur is characteristic of mitral regurgitation?

The characteristic murmur associated with mitral regurgitation is a blowing holosystolic (or pansystolic) murmur best heard at the apex of the heart, often radiating toward the left axilla. This type of murmur signifies the backflow of blood from the left ventricle into the left atrium during systole due to incompetent mitral valve closure. The timing of the murmur occurs throughout the entire systolic phase, which is why it is described as holosystolic.

In contrast, other murmurs listed are associated with different cardiac conditions. For example, an early diastolic murmur typically indicates regurgitation across a valve (like aortic regurgitation) during early diastole, rather than a backflow occurring during systole. A mid-systolic ejection murmur is usually due to ventricular outflow tract obstructions and occurs only in the middle of systole, while a late diastolic murmur can signify increased flow across the mitral valve (as in mitral stenosis) during the late points of diastole. Thus, the hallmark of mitral regurgitation being a holosystolic murmur at the apex distinctly sets it apart from the