Electrophysiologic Study and Ergonovine Provocation of Coronary Spasm in Unexplained Syncope.

A total of 38 patients with syncope in whom a cause was not assigned or suggested by the initial history, physical examination and electrocardiography (ECG) were studied. Twenty-four patients underwent cardiac examination with Holter ECG, electrophysiologic testing with programmed ventricular stimulation (EPS) and/or coronary arteriography including ergonovine provocation (ergonovine CAG). The study with Holter ECG, EPS and ergonovine CAG yielded a presumptive diagnosis in 36 patients (36/38=95%), 11 with vasospastic angina, 7 with ventricular tachycardia, 4 with ischemic heart disease, 9 with sick sinus syndrome (SSS), 1 with drug induced SSS, 3 with A-V block, 1 with supraventricular tachycardia, 1 with hypertrophic cardiomyopathy, 1 with aortic valve stenosis and 1 with carotid sinus syndrome (included are 1 patient with ventricular tachycardia+ischemic heart disease, 1 with SSS+vasospastic angina and 1 with ventricular tachycardia+vasospastic angina). Therapy based on these findings provided complete symptomatic relief in all patients during a mean follow up of 25±10 months (range 5-45 months).In conclusion, EPS and ergonovine CAG are useful in the diagnosis and therapy of unexplained syncope.