Left atrial and pulmonary “capillary” pressure curves during Valsalva's experiment

Abstract

Simultaneous measurements of the left atrial and pulmonary “capillary” pressures were made during the Valsalva maneuver in nine patients with mitral valve disease. 1. 1. The pulmonary “capillary” pressure curve paralleled the left atrial pressure curve both during and after the period of forced expiration. 2. 2. There was a decline in the pressure during the Valsalva maneuver. 3. 3. A pronounced decrease in the amplitude of peak 7 (representing opening of the mitral valve) during forced expiration was observed in all but one of the patients. In this patient mitral regurgitation was suspected and here the decrease in amplitude was less pronounced. 4. 4. After forced expiration was ended the pressures fell abruptly to below the resting values. This was followed by a rapid rise and overshoot above the normal levels. This overshoot phenomenon is attributed to the sudden increase in the pulmonary flow that follows release of the blood arrested in the venous system during the Valsalva maneuver.