Failure of ambulatory electrocardiographic monitoring to predict results of programmed electrical stimulation. Studies in patients with clinical ventricular tachyarrhythmias.

To test for an association between the results of ambulatory electrocardiographic monitoring (AEM) and programmed electrical stimulation (PES), or whether other factors better predict the results of PES, 57 patients (36 male and 21 female patients) presenting with either ventricular fibrillation (49 percent; 28/57) or sustained ventricular tachycardia (51 percent; 29/57) were studied. Each patient underwent AEM and PES using up to three ventricular extrastimuli. Sixty-three percent (36/57) had coronary disease; and of these, ventricular tachycardia was present during AEM in 64 percent (23/36) and induced by PES in 78 percent (28/36). With the addition of patients with other cardiac diagnoses, the results were 58 percent (33/57) and 60 percent (34/57), respectively. No AEM variable was positively associated with inducible ventricular tachycardia, including frequency of ventricular premature depolarizations, multiformity, couplets, or ventricular tachycardia. Clinical variables positively associated with inducible ventricular tachycardia were coronary disease, previous myocardial infarction, left ventricular dysfunction, male sex, and a history of recurrent arrhythmia. Therefore, clinical characteristics are more useful for predicting the results of PES than information derived from AEM.