Where is the point of maximum intensity (PMI) located when assessing a heart murmur?

The point of maximum intensity (PMI) when assessing a heart murmur is primarily determined by where the murmur is best heard, which corresponds to the specific valve area involved in the heart's function. Each heart valve—such as the mitral, tricuspid, aortic, and pulmonary valves—has an optimal location on the thoracic wall where any abnormal sounds associated with these valves are most pronounced during auscultation. For example, a murmur caused by mitral regurgitation is typically heard best over the left atrioventricular area.

Identifying the PMI is crucial for diagnosing the underlying cardiac issue, as it provides vital clues regarding the nature and origin of the murmur, which can indicate conditions such as valvular diseases or heart anomalies. Thus, focusing on the valve area where the murmur is best heard allows for accurate clinical assessment and aids in guiding further diagnostic and treatment decisions.