Aminophylline termination of dipyridamole stress as a trigger of coronary vasospasm in variant angina.
Dipyridamole testing represents an alternative to exercise stress testing for documentation of ischemia related to coronary artery disease (CAD). In such a case, ischemia is attributed to maldistribution of coronary flow during dipyridamole-induced vasodilation. The present study evaluated the potential role of dipyridamole testing in producing ischemia through a vasospastic mechanism, following rapid withdrawal of vasodilation induced by aminophylline. The possibility was tested in 36 in-hospital patients with variant angina pectoris who underwent dipyridamole infusion (up to 0.84 mg/kg over 10 minutes) with continuous 12-lead electrocardiographic and 2-dimensional echo monitoring. Medications were withdrawn from all patients. The test was pharmacologically stopped with the dipyridamole antidote (aminophylline, 80 to 240 mg intravenously over 1 to 3 minutes) in all patients. Two to 6 minutes after starting aminophylline infusion, 10 patients (28%) developed (greater than 0.10 mV) ST-segment elevation (2.9 +/- 0.8 mm from baseline), always accompanied by obvious asynergy detected by echocardiography, in the same electrocardiographic leads showing spontaneous or ergonovine-induced ST-segment elevation. Nitrates promptly resolved ischemia in all patients. At coronary angiography, 5 of these 10 patients showed significant CAD (greater than 70% lumen diameter reduction of at least 1 major coronary artery), whereas 5 had nonsignificant CAD. The rate pressure product at the onset of ST-segment elevation (after dipyridamole plus aminophylline) was considerably less than that recorded at peak exercise stress test in these patients (9,600 +/- 2,200 vs 18,400 +/- 4,900, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Consiglio Nazionale della Richerche, Institute of Clinical Physiology, Pisa, Italy.
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Lattanzi
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L'Abbate
D000328:Adult; D000628:Aminophylline / Q000008:administration & dosage / Q000627:therapeutic use*; D000788:Angina Pectoris, Variant / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects; D003327:Coronary Disease / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology; D003329:Coronary Vasospasm / Q000139:chemically induced* / Q000188:drug therapy / Q000503:physiopathology; D004176:Dipyridamole; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D013312:Stress, Physiological / Q000503:physiopathology
D000628:Aminophylline; D004176:Dipyridamole