INTRAVENOUS CARBOCHROMEN - A POTENT AND EFFECTIVE DRUG FOR ESTIMATION OF CORONARY DILATORY CAPACITY

Systemic and coronary haemodynamic effects of carbochromen (0.125 mg kg-1 min-1 for 40min i.v.) and dipyridamole (0.05 mg kg-1 min-1 for 10 min i.v.) were investigated in 18 patients without detectable heart disease. Both drugs induced a comparable increase in coronary blood flow (carbochromen: from 82 ±23 to 337±68ml.100g-1.min-1; dipyridamole: from 78±9 to 301 ±61 ml.100 g-1.min-1). This resulted in a minimal coronary resistance of 0.23±0.04mm Hg.ml-1 100g.min for dipyridamole and of 0.24±0.04mm Hg.ml-1.100g.min for carbochromen. In response to dipyridamole (n=12) heart rate increased from 73 to 94 beats min-1 (P<0.005) and mean aortic pressure fell from 89 to 78 mmHg (P<0.001). After administration of carbochromen (n = 6) no significant systemic effects occurred. Dipyridamole induced a significant increase in myocardial oxygen consumption by 46% (P<0.001 J; after application of carbochromen myocardial oxygen consumption remained unchanged. From these data it can be concluded that for the evaluation of coronary dilatory capacity carbochromen may be more suitable than dipyridamole because (1) maximal coronary vasodilation is induced without changes in myocardial oxygen consumption and (2) no systemic effects occur © 1990 The European Society of Cardiology.