Programmed electrical stimulation in patients with high-grade ventricular ectopy: electrophysiologic findings and prognosis for survival.

Abstract

The significance and treatment of ventricular premature beats (VPBs) in patients without sustained ventricular tachycardia (VT), sudden death, or syncope remains unclear. We undertook a prospective study of programmed electrical stimulation (up to two extrastimuli and burst pacing) in 73 patients (age 60 ± 10 years) with high-grade VPBs who had no evidence of sustained VT, sudden death, or syncope as determined by 48 hr of monitoring in the cardiac care unit and 48 hr Holter monitoring. Fifty-six patients (76.7%) had atherosclerotic heart disease, 10 (13.7%) had cardiomyopathy or valvular heart disease, and seven (9.6%) had no evident heart disease. Thirty-seven patients (50.7%) had Lown grade IVB VPBs, 30 (41.1%) had Lown grade IVA VPBs, and six (8.2%) had Lown grade III VPBs. Programmed electrical stimulation identified two groups of subjects: group 1 comprised 20 patients (27%) in whom VT or ventricular fibrillation was induced, group 2 comprised 53 patients (73%) in whom no ventricular arrhythmia or only two to four repetitive ventricular responses were induced. There was a significant difference between the presence of atherosclerotic heart disease, old myocardial infarction, and ejection fraction of less than 40% in group 1 compared with group 2. However, there was no significant difference in the grade of VPBs between the two groups. Seventeen of 20 patients from group 1 were placed on antiarrhythmic therapy (defined by programmed electrical stimulation), whereas group 2 patients were randomly assigned to prophylactic antiarrhythmic therapy. A total of 70 patients were followed up for 30 + 15 months. The incidence of sustained VT and/or sudden death (31.5% vs 2%; p < .001) was significantly higher in group 1 compared with group 2. There was no difference in the occurrence of sudden or nonsudden cardiac death between the treated and untreated patients in group 2. The probability of surviving 1 year (0.75 vs 1.0) and 48 months (0.35 vs 0.67) was significantly lower (p < .0008) in group 1 than in group 2. In conclusion programmed electrical stimulation defines high-and low-risk subsets for sudden death among patients with highgrade VPBs. Patients in whom arrhythmias are not inducible and those with ejection fractions of greater than 40% have a low incidence of sudden death and an excellent 1 to 2 year survival; these patients do not need prophylactic antiarrhythmic therapy. Circulation 70, No. 1, [43][44][45][46][47][48][49][50][51] 1984 In the last few years programmed cardiac stimulation has been used in the diagnosis and management of patients with recurrent sustained ventricular tachycardia (VT) and in survivors of out-of-hospital cardiac arrest.'1-9 The results of these studies have demonstrated that programmed cardiac stimulation can induce the clinical ventricular arrhythmia in approximately 75% to 90% of these patients. Furthermore, these studies'-'9 have also shown that use of antiarrhythmic agents that prevent the induction of ventricu-

Prediction of Sustained Ventricular Tachycardia Inducible by Programmed Stimulation in Patients With Coronary Artery Disease

“…[13][14][15][16][17][18] Studies that included patients regardless of the measured left ventricular ejection fraction have noted associations between a lower ejection fraction and inducible ventricular tachycardia. [13][14][15][16] An analysis restricted to patients with ejection fraction Ͻ0.40 did not confirm these observa- tions. 18 It seems likely that if one selects patients on the basis of significant left ventricular dysfunction, further stratification for the likelihood of finding inducible sustained ventricular tachycardia is not possible.…”

ACC/AHA guidelines for the early management of patients with acute myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Assessment of Diagnostic and Therapeutic Cardiovascular Procedures (subcommittee to develop guidelines for the early management of patients with acute myocardial infarction).

“…When programmed ventricular stimulation induced sustained ventricular tachyarrhythmia, the 1-year mortality rate, even on antiarrhythmic therapy, exceeded 30% versus 2% for patients with noninducible arrhythmias. 216 Because there are no randomized trials available to support the validity of this approach, however, the application of electrophysiologic study to evaluate ventricular ectopic activity occurring late after acute myocardial infarction remains controversial. 48 There is no indication for the use of electrophysiologic study to evaluate ventricular tachycardia or cardiac arrest in the acute phase of myocardial infarction (c48 hours).48 Signal-averaged electrocardiography is another promising technique that may prove beneficial in defining a subset of patients at high risk for sustained ventricular tachycardia.217…”

Nonsustained Ventricular Tachycardia in Coronary Artery Disease: Relation to Inducible Sustained Ventricular Tachycardia

“…Thus, these other tests cannot identify patients likely to benefit from antiarrhythmic therapy. In contrast, previous studies [9][10][11][12] have associated the presence of sustained ventricular tachycardia with an excess of sudden, as opposed to nonsudden, deaths. The signal-averaged electrocardiogram has yet to be tested prospectively in a large sample of patients with the characteristics of our study participants.…”

“…Sustained ventricular tachycardia induced by programmed electrical stimulation has been shown to predict death--specifically sudden death--in myocardial infarction survivors who have reduced ventricular function and present with asymptomatic ventricular ectopy or nonsustained ventricular tachycardia [9][10][11][12]. We evaluated whether electrocardiographic characteristics of spontaneous nonsustained ventricular tachycardia could predict the inducibility of sustained ventricular tachycardia by programmed electrical stimulation in a large sample of patients with documented coronary artery disease, reduced ventricular function, and spontaneous asymptomatic nonsustained ventricular tachycardia.…”