Effect of the Valsalva Maneuver on Blood Pressure

The Valsalva maneuver is used for many reasons, including equalizing ear pressure after air travel or "bearing down" during childbirth. It can also be a very useful diagnostic tool for heart arrhythmia.

Procedure

• The Valsalva maneuver is forced exhalation against a closed airway. You close your mouth and nose and "push" the air without breathing out. It's similar to the pressure of passing a bowel movement. In a cardiac setting, doctors will monitor an ECG and also listen to your heart during and after the maneuver.

Phase 1

• At the beginning of the movement, pressure in the chest cavity increases due to the pushing of air. The heart rate doesn't increase, but blood pressure increases as it's forced from the lungs into the heart.

Phase 2

• Next, the amount of blood coming into the heart (venous return) decreases. Less blood then goes out of the heart. This lowers blood pressure and increases heart rate.

Phase 3

• In this phase, you release your breath. Chest cavity pressure decreases, and blood flows normally from the lungs into the heart.

Phase 4.

• In Phase 4, blood pressure may rise slightly above normal before returning to baseline. Heart rate also returns to normal.

Diagnostics

• The Valsalva maneuver is useful in cardiology; some heart murmurs become louder or softer during different phases, depending on where they're located.