What maneuver is known to decrease the murmur associated with mitral valve prolapse?

The maneuver that is known to decrease the murmur associated with mitral valve prolapse is squatting. This action increases venous return to the heart, which enhances preload. As a result, the blood volume in the left atrium and ventricle increases, which can help to reduce the severity of the prolapse and subsequently decrease the intensity of the associated murmur.

In contrast, maneuvers that decrease preload, such as standing or the Valsalva maneuver, typically increase the murmur associated with mitral valve prolapse. Standing decreases venous return, leading to a reduction in blood volume in the heart and worsening the prolapse and murmur's intensity. The Valsalva maneuver, which involves forced expiration against a closed airway, also decreases venous return and leads to an increased murmur. Arm raising generally has a negligible effect on preload and is not typically associated with a significant change in the murmur related to mitral valve prolapse.

Understanding these dynamics is crucial in identifying and managing patients with mitral valve prolapse, where the interplay of preload and hemodynamics plays a vital role in the disease's presentation.