Therapeutic implications of diazepam in patients with elevated left ventricular filling pressure.

Diazepam (0.1 mg. per kilogram) was given intravenously to 12 patients with hemodynamic left ventricular failure at the time of cardiac catheterization. Anxiety was effectively relieved in 10 patients. Systemic and coronary hemodynamic parameters were assessed before and 5 and 15 minutes after diazepam. Heart rate, cardiac index, and left ventricular stroke-work index did not change significantly. Mean aortic pressure decreased in all patients (average of 10 mm. Hg) and left ventricular end-diastolic pressure (LVEDP) decreased from a mean +/- S.E.M. of 24.3 +/- 3 mm. Hg at rest to 16 +/- 2.1 at 5 minutes (p less than 0.001) and 15.8 +/- 2.1 at 5 minutes (p less than 0.002). Left ventricular angiography performed 30 minutes after diazepam did not increase LVEDP above the pre-diazepam control value. Systolic ejection period and tension-time index also decreased significantly after diazepam. Coronary hemodynamics and myocardial metabolism were unaltered by diazepam. The fall in LVEDP induced by diazepam is probably secondary to a decrease in arterial pressure (afterload) possibly associated with a decrease in venous return (preload). Our data therefore suggest that diazepam exerts a beneficial action on depressed left ventricular function and, thus, may be a sedative agent of choice in patients with myocardial infarction and heart failure.