[Study of the effects on coronary circulation and myocardial metabolism of a single intravenous dose of dihydralazine in 10 cases of primary myocardiopathy].

The effects of a single intravenous injection of dihydralazine (0.1 mg/kg) on coronary blood flow and myocardial metabolism were studied in 10 patients with primary congestive cardiomyopathy. Cardiac output and coronary blood flow increased significantly (p < 0,001 and p < 0,05); myocardial oxygen consumption, cardiac work and the coronary arteriovenous difference in lactates did not change significantly. However, the effects of dihydralazine are variable; coronary blood flow decreased in 2 patients; myocardial oxygen consumption increased in 3 patients; the coronary arteriovenous difference of lactate concentration fell or inversed in 5 patients. This data suggests that dihydralazine may have an undesirable effect on myocardial metabolism in some cases of congestive cardiomyopathy. Further long term studies are indicated to define the role of this drug in cardiac therapeutics.