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Electrophysiological testing and nonsustained ventricular tachycardia. Use and limitations in patients with coronary
D J Wilber1, B Olshansky, J F Moran
1Loyola University Medical Center, Maywood, IL 60153.
Insights
Electrophysiological testing helps identify patients with chronic coronary artery disease at high risk for sudden cardiac death. Inducible sustained ventricular arrhythmias predict adverse events, guiding therapy decisions.
Area of Science:
- Cardiology
- Electrophysiology
- Clinical Medicine
Background:
- Patients with chronic coronary artery disease and reduced ejection fraction are at risk for sudden cardiac death.
- Nonsustained ventricular tachycardia is a common finding in this population.
- The role of electrophysiological testing in risk stratification is crucial.
Purpose of the Study:
- To evaluate the prognostic value of inducible sustained ventricular arrhythmias in patients with coronary artery disease.
- To determine if electrophysiological testing can guide antiarrhythmic therapy to prevent sudden cardiac death.
Main Methods:
- 100 patients with asymptomatic nonsustained ventricular tachycardia, coronary artery disease, and low ejection fraction underwent electrophysiological testing.
- Patients were stratified based on inducible sustained ventricular arrhythmias (monomorphic VT, polymorphic VT/VF).
- Therapeutic strategies included no antiarrhythmic therapy, drug therapy for suppression, or rate-controlling therapy.
Main Results:
- 57 patients had no inducible sustained arrhythmias and were event-free.
- Inducible sustained arrhythmias were found in 43 patients.
- Persistently inducible sustained arrhythmias were associated with a significantly higher incidence of cardiac arrest or sudden death (50% at 2 years) compared to suppressed arrhythmias (11% at 2 years) or no inducible arrhythmias (6% at 2 years).
- Multivariate analysis identified persistently inducible sustained arrhythmias as the sole independent predictor of sudden death (RR 3.5).
Conclusions:
- Electrophysiological testing is valuable for risk stratification in patients with coronary artery disease and reduced ejection fraction.
- Patients without inducible sustained ventricular arrhythmias do not require antiarrhythmic therapy.
- Therapeutic intervention should be considered for patients with persistently inducible sustained ventricular arrhythmias to reduce the risk of sudden cardiac death.
Abstract:
Electrophysiological testing was performed in 100 consecutive patients with spontaneous asymptomatic nonsustained ventricular tachycardia, chronic coronary artery disease, and ejection fraction of less than 40%. Fifty-seven patients without inducible sustained ventricular arrhythmias were discharged on no antiarrhythmic therapy. Sustained monomorphic ventricular tachycardia was induced in 37 patients, and polymorphic ventricular tachycardia or ventricular fibrillation was induced in six patients. Of the 43 patients with inducible sustained ventricular arrhythmias, three had spontaneous cardiac arrest during serial drug testing and were excluded from further analysis. Twenty patients were discharged on drug therapy, resulting in suppression of inducible sustained ventricular arrhythmias. The remaining 20 patients with persistently inducible sustained arrhythmias were discharged on drug therapy, resulting in maximal rate slowing of the induced tachycardia. During a mean follow-up of 16.7 months, there were 10 recurrent cardiac arrests or sudden deaths. The 1- and 2-year actuarial incidence of these events was 2% and 6%, respectively, in patients without inducible sustained ventricular arrhythmias; 0% and 11%, respectively, in patients in whom inducible arrhythmias were suppressed; and 34% and 50%, respectively, in patients with persistently inducible sustained ventricular arrhythmias. Multivariate Cox analysis identified only the persistence of inducible sustained ventricular arrhythmias as a significant independent predictor of sudden death or recurrent sustained arrhythmias (p less than 0.001; relative risk, 3.5; 95% confidence intervals, 2.1-4.9). In this population, therapeutic intervention to prevent sudden death is unnecessary in patients without inducible sustained ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)