Programmed ventricular stimulation in coronary artery disease and dilated cardiomyopathy: influence of the underlying heart disease on the results of electrophysiologic testing.

In order to evaluate the clinical and prognostic significance of programmed ventricular stimulation (PVS), 100 patients were investigated. Twenty-four of 51 patients with coronary artery disease and 22 out of 49 with dilated cardiomyopathy had clinical ventricular tachycardia (VT). The study protocol included 24-h Holter ECG, cardiac catheterization and angiography, and PVS employing 1 and 2 premature extrastimuli and incremental pacing. In patients with coronary artery disease, VT was induced in 67% with prior VT and in 18% without such episodes (p less than 0.01). In dilated cardiomyopathy, however, patients with and without clinical VT did not differ with regard to VT inducibility (18% vs. 15%, NS). The inducibility of monomorphic sustained VT--most frequently induced in VT patients--was significantly higher in patients with coronary artery disease (p less than 0.05). Polymorphic nonsustained VT (in both coronary artery disease and dilated cardiomyopathy) was only initiated in patients without clinical VT. In patients with coronary artery disease, left ventricular ejection fraction could be correlated to clinical arrhythmia (p less than 0.001), while induced VT could only be correlated to depressed left ventricular function in patients with left ventricular aneurysm. Neither clinical nor induced VT could be correlated to left ventricular ejection fraction in patients with dilated cardiomyopathy. During a mean follow-up of 21 months, 7 patients died from sudden cardiac death. Six of them had clinical VT, but in only 1 patient with coronary artery disease was VT initiated. There was no apparent difference in the antiarrhythmic therapy of the patients with sudden death with respect to the surviving population. In conclusion, the response to PVS with the stimulation protocol applied is different in patients with coronary artery disease and dilated cardiomyopathy. The prognostic significance of the results obtained from PVS remains uncertain.