This is not to be confused with stage 4 of the Valsalva maneuver, in which the release of high intrathoracic pressure previously generated by forced expiration against a closed glottis, now restores venous return and cardiac output into a vasoconstricted circulation, stimulating the vagus nerve and leading to a slowing of the heart, or bradycardia.
This is not to be mistaken with stage 4 of the Valsalva maneuver, in which the release of high intrathoracic pressure previously generated by forced expiration against a closed glottis now restores venous return and cardiac output into a vasoconstricted circulation, stimulating the vagus nerve and causing the heart rate to slow down, or bradycardia.