Table 1:

Net physiologic effects during the Valsalva maneuver

Pressure ChangesCardiovascular Effects
Increased intrathoracic pressureDecreased thoracic venous return
Increased extrathoracic airway pressureDistention of extrathoracic venous system
Increased middle ear pressureDecreased stroke volume
Increased intracranial pressureDecreased cardiac output
Opening of the Eustachian tubePeripheral vascular constriction