What effect does the Valsalva maneuver have on the body?

The Valsalva maneuver involves a person attempting to exhale forcefully with a closed mouth and nose, which leads to a significant increase in intrathoracic pressure. This maneuver is often used in clinical settings, particularly to understand cardiovascular responses or to facilitate certain medical procedures.

When the intrathoracic pressure increases, several physiological changes occur. For instance, increased pressure within the thoracic cavity can lead to temporary alterations in blood flow and heart function, and it also affects venous return. The maneuver compresses the veins that return blood to the heart, impacting the flow dynamics during the maneuver.

This increase in intrathoracic pressure is a key feature of the Valsalva maneuver, as it can influence how blood flows back to the heart, the heart rate, and blood pressure, as well as assist in various medical assessments. It is not primarily aimed at reducing heart rate or improving lung function during exercise; instead, its mechanism is much more focused on altering pressure dynamics within the thoracic region.