Coronary responses to Valsalva maneuver in man

Effects of the Valsalva maneuver (VM) on the left coronary blood flow velocity (CFV) were assessed in 30 consecutive patients using an intracoronary Doppler probe. In 16 patients (group A), VM significantly decreased mean CFV (22±12 to 8±5 cm/s). In 14 patients (group B), the reduction of m CFV did not achieve statistical significance. VM significantly decreased aortic flow velocity, aortic pressure and systolic left ventricular pressure. The diastolic left ventricular pressure and right atrial pressure increased significantly during VM. The percent changes of these pressure parameters during VM were not significantly different between groups. The decrease of CFV was related to the magnitude of intratracheal pressure rise in group A. In 6 patients, systolic reverse flow was seen during VM. These data suggest that, although the effects of VM on CFV may vary between patients, increased intrathoracic pressure decreases CFV by decreasing coronary perfusion pressure in diastole and develops systolic reverse flow by increasing intramyocardial pressure. These differences in the response of CFV to VM may provide a useful means in assessing the mechanics that regulate coronary circulation in both normal and diseased states