What is an apical murmur associated with MR in the left ventricle?

The apical murmur associated with mitral regurgitation (MR) in the left ventricle is characterized as a holosystolic murmur. This type of murmur occurs throughout the entirety of systole, which corresponds to the time when the left ventricle contracts and the mitral valve fails to close properly, allowing blood to flow back from the left ventricle into the left atrium.

In the context of MR, the backflow of blood during systole creates a sound that is typically described as holosystolic or pansystolic because it starts with the first heart sound and continues until the second heart sound. The murmur is most prominent at the apex of the heart and may radiate toward the left axilla. It's distinctive for its continuous nature during systole, making it easy to recognize during auscultation.

This progressive increase in intensity associated with the characteristic timing of the murmur helps differentiate it from other types of murmurs that may occur during diastole or have other definitions of duration, such as late systolic or early diastolic murmurs, which do not relate to the specific hemodynamic changes of MR in the same way.