Which of the following statements is true regarding innocent murmurs and maneuvers that decrease venous return?

Innocent murmurs, also known as functional murmurs, are typically soft, short, and occur in the absence of any structural heart disease. They are often influenced by hemodynamic changes, which can be affected by maneuvers that alter venous return to the heart.

When maneuvers that decrease venous return are performed—such as standing up or performing the Valsalva maneuver—there is a reduction in the volume of blood returning to the heart. This decrease in venous return leads to a lower stroke volume and can result in diminished blood flow across the heart valves, making innocent murmurs less pronounced. Therefore, the murmur intensity typically reduces.

Understanding the relationship between maneuvers and venous return is crucial in clinical settings. In contrast to systemic changes that increase venous return, such as squatting, which can accentuate murmur intensity, decreasing venous return allows for the differentiation between innocent murmurs and those that may be indicative of pathologies. Such discernment helps to ensure that clinical assessments of heart sounds remain accurate and reflects the underlying physiology of the cardiovascular system.