stroke volume, heart rate, arterial pressure and dp/dt It is concluded that the degree of LVEDP increase on were not significant. During exercise, mean LVEDP was exercise in patients with coronary artery disease is in higher (P < 0.05) in patients with abnormal post#exercise part related to the number of severely diseased coronary electrocardiograms. Other hemodynamic differences bearteries and that an abnormal postexercise electrocardiotween patients with normal and abnormal postexercise gram is associabed with a more marked increase in left electrocardiograms were insignificant. ventricular end-diast’olic pressure during exercise. Hemodynamic Effects of Ethactynic Acid in Patients with Acute Myocardial Failure MELVIN M. SCHEINMAN, MD/MURRAY A. BROWN, BA and ELLIOT RAPAPORT, MD San Frencisco, California Eleven pat,ients wit’h persistent acute heart failure despite previous digit,alization were studied in a coronary care unit. A no. 1 nylon catheter was inserted percutaneously and flow directed into the pulmonary artery. A no. 5 nylon catheter was passed percutaneously into the femoral artery and advanced into the aorta, and cardiac output was determined by the Fick method. After control measurements, 50 to 75 mg of ethacrynic acid was administered intravenously. After a plateau in urinary output was achieved (2 to 10 hr), studies were repeated. After ethacrynic acid mean pulmonary arterial systolic pressure fell from 50.3 f 17.6 to 35.4 + 8.7 mm Hg (P < 0.01) and diastolic pressure fell from 23.0 * 10 to 12.5 t 4.8 mm Hg (P < 0.025). Although 0, consumption tended to fall, mean 0, consumption, heart rate, mean aortic pressure and cardiac output did not differ significantly from control values. Mean arterial-mixed venous (A-V) 0, content difference fell from 5.51 * 1.25 to 4.99 +0.90 vol ,% (P < 0.05), and mean urine output rose from 32 4 10 to 335 * 132 ml/hr (P < 0.001). Dyspnea decreased in all patients. Patients with acute heart failure appear to operate on the ‘Ylat” portion of a depressed Starling’s curve in that decreases in filling pressure produced with ethacrynic acid were not associated with significant changes in stroke volume. The tendency for 0, consumption and A-V 0, difference to fall is probably related to the decreased respiratory work induced by decongestion. Ethacrynic acid appears to be a safe and effective drug for patients with acute heart failure. Cardiac Metabolism in Cyanotic Congenital Heart Disease JAMES SCHEUER, MD, FACC/JAMES A. SHAVER, MD, FACC/FRANK W. KROETZ, MD and JAMES J. LEONARD, MD, FACC Pittsburgh, Pennsylvania Eight normal subjects and 7 cyanotic patients (mean 0, saturation of Sl%), 5 with tetralogy of Fallot and 2 with Eisenmenger’s syndrome, were studied in the fasting state by coronary sinus catheterization. In the resting state mean coronary flows (la11 aminopyrine) were 102 ml/100 g per min in normal and 72 in cyanotic patients (P < 0.05) and oxygen extractions [arterial-coronary sinus (A-CS)] were 11.5 and 14.6 ml/100 ml in normal and cyanotic patients. (P < 0.05). Myocardial oxygen consumpt,ion and arterial and coronary sinus lactate/pyruvate ratios were the same in the resting state in normal and cyanotic patients. Seven normal and 5 cyanotic patients were exercised on a bicycle ergometer at fixed work loads which produced similar mean tension-time indexes in the two groups. In cyanotic patients, exercise caused a fall in arterial 0, and A-CS 0, extraction so that coronary sinus 0, reached low levels and 0, delivery t.ended to be more dependent upon myocardial flow. In the 2 patients with Eisenmenger’s syndrome coronary sinus OZ averaged 2.8 ml/100 ml and coronary flow exceeded the limibs of the method. Lactate extract.ion was the same in normal and cyanotic patients, but arterial lactate and lactate consumpt.ion were higher in the lat,ter. Arterial and coronary sinus lactate/ pyruvate ratios were the same. Glucose and free fatty acid metabolism were the same in normal and cyanotic patients during rest and exercise. These results indicate that although mechanisms of oxygen delivery to the myocardium may differ in normal subjects and some patients with cyanotic congenital heart disease, left ventricular myocardial oxidative metabolism is intact even in the presence of hypoxemia. 126 The Amdc8n Journal of CARDIOLODY