Blood pressure responses to the Valsalva maneuver in cardiac patients with and without congestive failure.

Compensated cardiac patients, like normal subjects, on performing the Valsalva maneuver show a decrease in systolic, diastolic, and pulse pressures during the blowing effort and a characteristic hy-pertensive overshoot after the release of the strain. Cardiac patients in congestive failure show the "failure response" with a maintenance of the systolic, diastolic, and pulse pressures during the ex-piratory strain and an absence of the overshoot afterwards. Experimental and clinical observations in patients indicate that this "failure response" is due to elevation of the right ventricular diastolic pressure, which interferes with the normal obstruction of venous return during the blowing effort of the Valsalva maneuver.