Trial: Effect of oral beta-blocker therapy on microvolt T-wave alternans and electrophysiology testing in patients with ischemic cardiomyopathy.
Authors: Zacks ES, Morin DP, Ageno S, Janik M, Mauer AC, Markowitz SM, Mittal S, Iwai S, Shah BK, Lerman BB, Stein KM.
Reference: Am Heart J. 2007 Mar;153(3):392-7.
Purpose: To determine whether use of oral beta-blockers within 24 hours of TWA testing influences the yield and predictive value of TWA testing and EPS. Arrhythmia-free survival and overall survival were examined.
Number of Patients: 387
Number of Centers: 1
Design: Single center cohort
Authors Conclusion: Oral beta-blocker therapy appears to have no effect on the yield or predictive value of EPS or TWA testing (performed during rapid atrial pacing) in patients with coronary artery disease, diminished left ventricular function, and history of nonsustained ventricular tachycardia.
Key words: T wave alternans, beta-blocker, ventricular arrhythmia, death, coronary heart disease
Comment: As oral beta-blocker therapy appears to have no effect on the yield or predictive value of TWA testing for VT, VF, or death, it may not be necessary to routinely hold beta-blockers before testing in the population. (The applicability of the results of this study to clinical practice depends in part on whether or not TWA results obtained during atrial pacing can be extrapolated to TWA during exercise testing, and prior data have suggested a high concordance rate.)
Ongoing Related Studies:
- MASTER II: Microvolt T-Wave Alternans Testing for Risk Stratification of Post MI Patients
- MASTER I: Microvolt T-Wave Alternans Testing for Risk Stratification of Post MI Patients
- Study to Compare TWA Test and EPS Test for Predicting Patients at Risk for Life-Threatening Heart Rhythms (ABCD Study)
- Prognostic Significance of T-Wave Alternans
- Assessment of Noninvasive Methods to Identify Patients at Risk of Serious Arrhythmias After a Heart Attack
- Omega 3 PUFAs and Microvolt TWA in Patients with Ventricular Arrhythmia
- T-Wave Alternans in Hemodialysis
Summary written by Andrea Russo, MD
