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Conversion of sustained into nonsustained ventricular tachycardia during therapy assessment by programmed ventricular
W Schoels1, J Brachmann, C Schmitt
1Department of Cardiology, University of Heidelberg, Federal Republic of Germany.
Abstract:
Serial electropharmacologic testing using up to 11 different antiarrhythmic drugs was performed in 130 consecutive patients (107 men, 23 women, ages 56 +/- 12) with inducible sustained ventricular tachycardia (VT). After 4 +/- 2.3 drug tests, complete suppression of VT inducibility (defined as less than 6 consecutive beats, mean 1.4 +/- 1.6) was achieved in 86 patients (66%), whereas in 44 patients (34%) nonsustained VTs (greater than or equal to 6 consecutive beats, less than 30 seconds in duration) were still inducible. There was no statistical difference between both groups regarding age, sex, underlying heart disease, ejection fraction or entry arrhythmia. After a mean follow-up period of 19 +/- 17 months, 24 patients (18%) had died, 8 (6%) suddenly. Eight patients (6%) experienced recurrent sustained VT. Symptomatic recurrences (sudden death or VT) occurred in 10 (11%) and 6 patients (13%, difference not significant), respectively. Probability of arrhythmia-free survival was comparable for patients with 0 to 5, 6 to 10, 11 to 15 and 16 to 32 inducible ventricular complexes with discharge medication. The negative predictive value of electropharmacologic drug testing was about 89%, irrespective of the maximal number of inducible complexes used for the definition of a negative test result. It is therefore concluded that conversion of sustained into nonsustained VT during therapy assessment by programmed ventricular stimulation indicates a positive drug effect.
Insights
Electrophysiologic testing effectively suppresses inducible ventricular tachycardia (VT) in many patients. Converting sustained VT to nonsustained VT during testing indicates a positive antiarrhythmic drug effect.
Area of Science:
- Cardiology
- Clinical Electrophysiology
- Pharmacology
Background:
- Sustained ventricular tachycardia (VT) poses a significant risk of sudden cardiac death.
- Electrophysiologic testing is crucial for guiding antiarrhythmic drug therapy in patients with VT.
Purpose of the Study:
- To evaluate the efficacy of serial electropharmacologic testing in suppressing inducible VT.
- To determine the predictive value of electrophysiologic testing for long-term outcomes in VT patients.
Main Methods:
- Serial electrophysiologic testing with up to 11 antiarrhythmic drugs in 130 patients with inducible sustained VT.
- Assessing VT inducibility and classifying outcomes as complete suppression or inducible nonsustained VT.
- Follow-up evaluation for mortality, sudden death, and recurrent VT.
Main Results:
- Complete suppression of VT inducibility was achieved in 66% of patients after drug testing.
- No significant differences in baseline characteristics were observed between groups with and without VT suppression.
- Arrhythmia-free survival probability was comparable across different levels of inducible ventricular complexes on discharge medication.
- The negative predictive value of electrophysiologic testing was approximately 89%.
Conclusions:
- Conversion of sustained VT to nonsustained VT during programmed ventricular stimulation indicates a positive drug effect.
- Electropharmacologic testing is a valuable tool for assessing antiarrhythmic drug efficacy in VT management.
- The findings support the use of electrophysiologic testing to guide therapy and predict outcomes in patients with ventricular tachycardia.