The Effect of Procainamide on T Wave Alternans
- 1 May 1999
- journal article
- research article
- Published by Wiley in Journal of Cardiovascular Electrophysiology
- Vol. 10 (5), 649-654
- https://doi.org/10.1111/j.1540-8167.1999.tb00241.x
Abstract
The measurement of microvolt level T wave alternans (TWA) is a technique for detecting arrhythmia vulnerability. Previous studies demonstrated that the magnitude of TWA is dependent on heart rate. However, the effects of antiarrhythmic drugs on TWA are unknown. This was a prospective evaluation of intravenous procainamide on TWA in 24 subjects with inducible sustained ventricular tachycardia (VT). Measurements of TWA were performed at baseline in the drug-free state and after procainamide loading (1,204+/-278 mg). Recordings were made in normal sinus rhythm, and during atrial pacing at 100 beats/min and 120 beats/min. The magnitude of TWA in the vector magnitude lead was decreased by procainamide at all heart rates: 0.6+/-0.8 to 0.3+/-0.4 microV in sinus rhythm, 2.0+/-1.6 to 0.7+/-0.7 microV at 100 beats/min, and 3.0+/-2.0 to 1.7+/-1.8 microV at 120 beats/min (P<0.001 by analysis of variance). The sensitivity of TWA for the induction of VT at baseline was 5% in sinus, 60% at 100 beats/min, and 87% at 120 beats/min, while it decreased with procainamide to 5%, 19%, and 60%, respectively. Decreases in TWA in response to procainamide were independent of the antiarrhythmic effects on VT inducibility. These results indicate that the magnitude of TWA decreases with acute procainamide loading and this effect decreases the sensitivity of TWA for the induction of sustained VT.Keywords
This publication has 19 references indexed in Scilit:
- T Wave Alternans During Exercise and Atrial Pacing in HumansJournal of Cardiovascular Electrophysiology, 1997
- Improved Survival with an Implanted Defibrillator in Patients with Coronary Disease at High Risk for Ventricular ArrhythmiaNew England Journal of Medicine, 1996
- Efficacy and safety of procainamide in preventing arrhythmias after coronary artery bypass surgeryThe American Journal of Cardiology, 1996
- Predicting Sudden Cardiac Death From T Wave Alternans of the Surface Electrocardiogram:Journal of Cardiovascular Electrophysiology, 1996
- Dynamic Tracking of Cardiac Vulnerability by Complex Demodulation of the T WaveScience, 1991
- Prediction of successful suppression of sustained ventricular tachyarrhythmias by serial drug testing from data derived at the initial electrophysiologic studyJournal of the American College of Cardiology, 1988
- Out-of-Hospital Cardiac ArrestNew England Journal of Medicine, 1988
- Risk Stratification and Survival after Myocardial InfarctionNew England Journal of Medicine, 1983
- The response to procainamide during electrophysiologic study for sustained ventricular tachyarrhythmias predicts the response to other medications.Circulation, 1983
- Electrical alternation of the T-wave: Clinical and experimental evidence of its relationship with the sympathetic nervous system and with the long Q-T syndromeAmerican Heart Journal, 1975