A Comparison of Intravenous Elantan and Frusemide in Patients with Chronic Cardiac Failure

Abstract

Opiates and loop diuretics are the mainstay of treatment of acute pulmonary oedema, but it is now recognized that immediate response to intravenous loop diuretics is acute vasoconstriction with impaired cardiac performance. It therefore seemed appropriate to compare the effects of intravenous isosorbide 5-mononitrate and frusemide on systemic and coronary haemodynamics in a group of patients with chronic cardiac failure at cardiac catheterization. Intra-arterial blood pressure was recorded from the ascending aorta, pulmonary capillary wedge pressure and cardiac output were measured using a Swan-Ganz thermodilution catheter. Coronary venous blood flow was measured using a thermodilution technique and A-V oxygen difference across the myocardium was obtained from simultaneous blood sampling in the aorta and coronary sinus. Absolute myocardial nutrient blood flow was measured using a ¹³³Xe clearance technique.Frusemide in a dosage of 0.5 mg/kg given intravenously provoked acute vasoconstriction with falls in cardiac output and stroke volume. Pulmonary capillary wedge pressure was unchanged in the first 60 min after administration of frusemide. Isosorbide 5-mononitrate in a dosage of 15 mg intravenously, significantly reduced the pulmonary capillary wedge pressure within 5 min, and with the subsequent fall in systolic arterial blood pressure, cardiac output was maintained.These results suggest that intravenous isosorbide 5-mononitrate could well be of value in the immediate management of the patient with acute pulmonary oedema.