Hemodynamic effects of hydralazine in mitral valve prolapse with regurgitation.

Vasodilators cause the earlier occurrence of click and prolong the duration of regurgitation murmur in mitral valve prolapse (MVP), meanwhile, they also decrease the intensity of murmur. To investigate the net effects of vasodilators on mitral regurgitation (MR) caused by MVP, we studied the hemodynamic responses to intravenous hydralazine in 10 patients with MVP and associated MR. The results showed that hydralazine reduced systemic vascular resistance by 28% (1705 +/- 307 to 1223 +/- 227 dyne-sec-cm5 p less than 0.001) and produced a 30% increase in cardiac output (4.4 +/- 0.7 to 5.7 +/- 0.7 l/min, p less than 0.001). The forward stroke volume increased by 18% (56 +/- 12 to 66 +/- 11 ml, p less than 0.001), while regurgitant stroke volume fell by 14% (46 +/- 22 to 40 +/- 23 ml, p less than 0.05), with a resultant slight fall in pulmonary capillary wedge v wave (13 +/- 5 to 11 +/- 3 mmHg, p = 0.05). We thus suggest that hydralazine has beneficial hemodynamic effects on MVP with regurgitation, and may be effective in the treatment of these patients.