ACUTE EFFECTS OF DIGITALIS AND ENALAPRIL ON THE NEUROHORMONAL PROFILEOF CHAGASIC PATIENTS WITH SEVERE CONGESTIVE-HEART-FAILURE

Chagasic patients with congestive heart failure are usually treated wi th digitalis and converting enzyme inhibitors. According to the neurog enic and dysautonomic theories, chagasic patients would not benefit fr om these drugs. To clarify this controversial issue, we have studied p atients with congestive heart failure and suspected Chagas' heart dise ase. All patients received intravenous methyl-digoxin for 24 h and ora l enalapril for 96 h. Blood samples for plasma norepinephrine, aldoste rone and renin were taken at baseline, after acute digitalization and following enalapril. Based on the serology for Chagas' disease, the pa tients were divided into non-chagasic and chagasic patients. In the ch agasic group three patients were in functional class III and 3 were in functional class IV. In the non-chagasic group five patients were in functional class III and 2 were in functional class IV. Both groups ha d a marked and quantitatively similar degree of neurohormonal activati on. All patients improved at least one functional class and lost more than 5 kg of body weight with treatment. The chagasic patients had a s tatistically significant reduction in plasma norepinephrine (2262+/-14 07 to 865+/-390, P<0.008, pg/ml, M+/-S.D), plasma aldosterone (330+/-1 68 to 155+/-75, P<0.01, pg/ml, M+/-S.D.) and plasma renin activity (14 +/-13 to 2+/-1.6 ng/ml per h, M+/-S.D., P<0.05), with digitalis. Follo wing enalapril, norepinephrine and aldosterone there was a further but non-significant reduction, when compared to postdigitalis values. The se results indicated that chagasic patients do benefit from digitalis and enalapril. Furthermore, the prominent and significant reduction in all three neurohormones suggest that the parasympathetic and sympathe tic systems of these chagasic and non-chagasic patients, are respondin g to the neuromodulatory effects of digitalis and enalapril.