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[Captopril in acute myocardial infarct: its effect on infarct size and arrhythmias]
W D Bussmann1, G Micke, R Hildenbrand
1Abteilung für Kardiologie, Zentrum der Inneren Medizin der Universität Frankfurt/Main.
Insights
Captopril treatment in heart attack patients reduced infarct size and arrhythmias compared to placebo. This angiotensin-converting enzyme inhibitor improved electrical stability and necrosis index, offering benefits beyond standard nitroglycerin therapy.
Area of Science:
- Cardiology
- Pharmacology
- Clinical Medicine
Background:
- Myocardial infarction (heart attack) remains a leading cause of mortality.
- Early intervention is crucial to limit infarct size and prevent life-threatening arrhythmias.
- Angiotensin-converting enzyme (ACE) inhibitors are established treatments for cardiovascular conditions.
Purpose of the Study:
- To evaluate the efficacy of captopril in reducing infarct size and arrhythmias post-myocardial infarction.
- To assess the impact of captopril on myocardial necrosis and electrical stability.
- To determine if captopril provides additional benefits to standard nitroglycerin treatment.
Main Methods:
- Prospective, randomized, placebo-controlled, double-blind study.
- 46 patients with myocardial infarction received either captopril (intravenous bolus followed by infusion) or placebo for 48 hours.
- Measurements included QRS complexes (necrosis index), ventricular extrasystoles, ventricular fibrillation incidence, and creatine-kinase infarct weight.
Main Results:
- Captopril significantly reduced Q-wave amplitudes (necrosis index) compared to placebo (P < 0.05).
- Fewer ventricular extrasystoles (P < 0.02) and no cases of ventricular fibrillation were observed in the captopril group.
- Mean arterial blood pressure decreased more significantly in the captopril group during the first hour (P < 0.01).
- Creatine-kinase infarct weight showed a non-significant trend towards reduction with captopril.
Conclusions:
- Captopril demonstrates a favorable influence on infarct size and electrical stability in acute myocardial infarction.
- The benefits of captopril are additive to standard nitroglycerin treatment.
- Captopril may be a valuable therapeutic option for managing acute myocardial infarction to reduce infarct size and prevent arrhythmias.
Abstract:
The effect of captopril on infarct size and arrhythmias was determined in a prospective, randomized, placebo-controlled double-blind study of 46 patients (9 women, 37 men; mean age 61 [38-86] years). Within 2-18 hours of entry into the study these patients received either a slow intravenous bolus injection of 2.5 or 5.0 mg captopril followed by a continuous infusion of 1.5-2.0 mg/h for a period of 48 hours (n = 22), or of a placebo by the same mode of administration (n = 24). The two groups were comparable as to age, infarct site and time of intervention. All patients, except one in each group, also received nitroglycerin (1.2-6.0 mg/h intravenously). QRS complexes were measured to provide a necrosis index. Q-wave amplitudes decreased under captopril (-0.08 +/- 0.04 mV) while increasing under placebo (+0.15 +/- 0.04 mV; P less than 0.05). The number of ventricular extrasystoles in the first 24 hours after onset of treatment or on placebo was 25/h and 9/h, respectively (P less than 0.02). Ventricular fibrillation occurred in 7 patients of the placebo group, in none of the captopril group. Creatine-kinase infarct weight was 59 and 45 gram-equivalents, respectively (placebo vs treated group: not significant). The mean arterial blood pressure fell by 14 mm Hg during the first hour in the captopril group, but by only 3 mm Hg on placebo (P less than 0.01). These results indicate that captopril has a favourable influence on infarct size and electrical stability which is additional to that provided by standard nitroglycerin treatment.