[Combined use of dihydralazine and nitroglycerin during and after cardiac surgery (author's transl)].

The haemodynamic effect of combined intravenous administration of 18 mg/h dihydralazine and 0.6 mg/h nitroglycerine was examined in the intraoperative and postoperative phases of cardiac surgery (replacement of the aortic and mitral valve or of both valves, and aortocoronary bypass surgery(. Indication for therapy was supplied by a preoperative cardiac index below 2.8 l/min . m2 and an enhanced peripheral resistance above 1200 dyne . sec . cm-5. During a 19-hour observation period the haemodynamic parameters such as cardiac index (+36%) and stroke index (+19%) increased significantly within the investigated group, whereas the peripheral vascular resistance dropped by 16% and the left atrial pressure by 20%. Arterial mean pressure and heart rate did not change. In a patient group treated exclusively with nitroglycerin, the cardiac index decreased (-8%), while the peripheral vascular resistance increased (+6%); an untreated control group showed an increase of the cardiac index by 5%, whereas there was no appreciable change in peripheral vascular resistance and stroke index. The combined use of dihydralazine and nitroglycerin during the perioperative phase of cardiac surgery appears recommendable, since it is possible by such administration to monitor cardiac preload and afterload due to selectivity of the pharmacological sites of action.