Cardiovascular responses to Valsalva maneuver in physically trained and untrained normal subjects

To elucidate whether the Valsalva maneuver (VM) can distinguish different degrees of normal ventricular function and parasympathetic tone, we studied 10 physically untrained and 18 trained normal individuals who regularly performed isotonic exercises. Both groups were submitted to an exercise stress test. An electrocardiogram and an M-mode echocardiogram were recorded before and during VM. The arterial pressure, heart rate and ventricular function responses to the maneuver were evaluated. The end diastolic volume, ejection fraction, circumferential fiber shortening and left ventricular posterior wall thickness were greater at rest in the trained group than in the untrained one. In both groups, during the straining phase of the VM the volumes and end systolic stress decreased and the systolic function indexes increased, but the changes were more pronounced in the trained subjects. In spite of these differences, the arterial pressure and heart rate responses were similar in both groups. It can thus be concluded that only changes in ventricular function distinguish physically trained vs untrained subjects during VM.