Effects of enalapril on ventricular volumes and neurohumoral status after inferior wall myocardial infarction.
The activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system and its beneficial modification with the use of angiotensin-converting enzyme inhibin after inferior wall myocardial infarction (MI) was evaluated. Fifty patients with acute inferior MI were randomly assigned to receive 5 mg per day of either enalapril or placebo after admission. Blood tests for neurohormone levels and echocardiograms were performed at initial examination and 4 weeks later. Baseline characteristics were similar in the two groups. Four weeks after randomization, patients treated with enalapril had lower end-diastolic volume (146 +/- 29 vs 167 +/- 15 ml; p = 0.04), end-systolic volume (56 +/- 18 vs 107 +/- 17 ml; p = 0.03), serum norepinephrine levels (320 +/- 93 vs 465 +/- 77 pg/ml; p < 0.01), angiotensin II levels (18 +/- 6 vs 54 +/- 11 pg/ml; p < 0.01), and atrial natriuretic polypeptide levels (106 +/- 9 vs 122 +/- 17 pg/ml; p = 0.05) than patients given placebo. The incidence of heart failure after MI was also lower in this group (4% vs 16%; p = 0.009). Results show that there is early neurohumoral activation in the course of acute inferior wall MI. Enalapril reduces neurohumoral levels and preserves ventricular volumes. These effects were associated with a reduction in the incidence of heart failure 4 weeks after MI in these patients.
González-Fernández
R A
RA
Department of Internal Medicine, San Juan City Hospital, Puerto Rico.
Altieri
P I
PI
Lugo
J E
JE
Fernández-Martínez
J
J
D000368:Aged; D000450:Aldosterone / Q000097:blood; D000804:Angiotensin II / Q000097:blood; D002306:Cardiac Volume / Q000187:drug effects*; D004311:Double-Blind Method; D004656:Enalapril / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D009638:Norepinephrine / Q000097:blood; D016277:Ventricular Function, Left / Q000187:drug effects*
D000804:Angiotensin II; D000450:Aldosterone; D004656:Enalapril; D009638:Norepinephrine