Author + information
- Received November 14, 1985
- Revision received February 19, 1986
- Accepted March 21, 1986
- Published online September 1, 1986.
- Peter J. Schwartz, MD, FACC*,1,
- Silvia G. Priori, MD1,
- Emilio Vanoli, MD1,
- Antonio Zaza, MD1 and
- Giulio Zuanetti, MD1
- ↵*Address for reprints: Peter J. Schwartz, MD, Istituto di Clinica Medica Generale, Pad. Sacco, Via Francesco Sforza 35, 20122 Milan, Italy.
The potential role of calcium entry blockers in the prevention of life-threatening arrhythmias associated with acute myocardial ischemia and reperfusion is still controversial. In 98 anesthetized cats, the effect of diltiazem was examined in two experimental models. In protocol I, ventricular tachycardia or fibrillation was consistently induced by the interaction between a 2 minute coronary artery occlusion and a 30 second left stellate ganglion stimulation. After three trials under control conditions, if the same pattern of arrhythmia was induced, the drug under study was administered and three additional trials were performed. In 16 animals the administration of saline solution did not modify the pattern of arrhythmias. In contrast, diltiazem (0.1 mg/kg body weight plus 0.2 mg/kg per h) abolished both ventricular tachycardia and fibrillation that had occurred in 64 and 36%, respectively, of the cats in the control state.
In protocol II, a 20 minute coronary artery occlusion was released in three groups; one served as the control group, one received diltiazem 15 minutes before occlusion and one received diltiazem 3 minutes before reperfusion. The incidence of reperfusion ventricular fibrillation was 62% (16 of 26) in the control group. It was significantly (p < 0.05) reduced by diltiazem administered before the occlusion to 25% (4 of 16), whereas it was not affected when diltiazem was administered just before reperfusion (7 [47%] of 15).
These results indicate that diltiazem exerts a striking protective effect against the malignant arrhythmias induced by the combination of acute myocardial ischemia and sympathetic Hyperactivity. Diltiazem was also effective in reducing the incidence of life-threatening re-perfusion arrhythmias. The potential of this drug for reducing the incidence of malignant arrhythmias in patients with ischemic heart disease warrants careful evaluation.
- Received November 14, 1985.
- Revision received February 19, 1986.
- Accepted March 21, 1986.
- American College of Cardiology Foundation