USE OF ISOPROTERENOL DURING PROGRAMMED VENTRICULAR STIMULATION IN PATIENTS WITH CORONARY-ARTERY DISEASE AND NONSUSTAINED VENTRICULAR-TACHYCARDIA

Twenty-three consecutive patients (20 men and 3 women) with coronary a rtery disease and nonsustained ventricular tachycardia (VT) in whom su stained VT was not inducible in a baseline electrophysiology test unde rwent repeated testing during isoproterenol infusion to determine the inducibility of sustained monomorphic VT. After the baseline study, ea ch patient received a 2 to 4 mu g/min infusion of isoproterenol (mean 2.5 +/- 0.8 mu g/min). The sinus cycle length shortened by a mean of 2 9% +/- 9% and programmed stimulation was repeated. Nineteen patients h ad no inducible sustained, monomorphic VT, two patients had only induc ible nonsustained VT, and two patients had ventricular fibrillation. P atients were followed up for 10 to 20 months (mean 14.4 +/- 2.9 months ) and had no syncope, sustained monomorphic VT, or sudden death. Isopr oterenol infusion during programmed stimulation in patients with coron ary heart disease and nonsustained VT does not facilitate the inductio n of sustained monomorphic VT.