Use of BetaBlockers during MTWA test in DCM patients


The new paper of Murata et al. “Effect of long-term beta-blocker therapy on MicroVolt-level T-wave Alternans in association with the improvement of the cardiac sympathetic nervous system and systolic function in patients with non-ischemic heart disease (Circ J. 2003;67:821-5) is interesting because for the first time the effect of Beta-Blocker is analysed specifically in Non-Ischemic Heart Disease patients: about 30% of the MTWA positive patients became MTWA negative after oral Beta Blocker administration.


This can explain the limited results of MTWA as Arrhythmic Predictor in the Marburg (Grimm et al(1)) Cardiomiopathy study  because all the patients were tested with BetaBlocker washout. In all the other clinical trails on DCM patients or including DCM patients( Adachi et al (2), Kitamura et al(3), Hohnloser et al(4), Bloomfield (5), Klingenhaben et al)the patients have been tested without BetaBlockers washout and MTWA was a good predictor of Tachyarrhythmic events.


Also in the largest Clinical Trial of Ikeda (850 patients) in Ischemic patients, the MTWA test was performed under current therapy.


Therefore it is better to test all patients under their actual therapy. If the test is indeterminate because of low Max HR, the test has to be repeated immediately after( in most of cases the MAX HR is higher in the second test ). Only if the second test is also indeterminate it is worth to retest the patient with Beta Blocker washout.





1.             Grimm W, Christ M, Bach J, Muller H, Maisch B. Noninvasive Arrhythmia Risk Stratification in Idiopathic Dilated Cardiomyopathy: Results of the Marburg Cardiomyopathy Study. Circulation. 2003;108:2883-2891.

2.             Adachi K, Ohnishi Y, Yokoyama M. Risk stratification for sudden cardiac death in dilated cardiomyopathy using microvolt-level T-wave alternans. Jpn Circ J. 2001;65:76-80.

3.             Kitamura H, Ohnishi Y, Okajima K, Ishida A, Galeano E, Adachi K, Yokoyama M. Onset heart rate of microvolt-level T-wave alternans provides clinical and prognostic value in nonischemic dilated cardiomyopathy. J Am Coll Cardiol. 2002;39:295-300.

4.             Hohnloser SH, Klingenheben T, Bloomfield D, Dabbous O, Cohen RJ. Usefulness of microvolt T-wave alternans for prediction of ventricular tachyarrhythmic events in patients with dilated cardiomyopathy: results from a prospective observational study. J Am Coll Cardiol. 2003;41:2220-4.

5.             Bloomfield D. A Prospective Study of T Wave Alternans as a Predictor of Outcomes in Patients with Congestive Heart Failure. In: Annual Scientific Session, American College of Cardiology - Late Breaking Clinical Trials; 2003.

6.             Klingenheben T, Zabel M, D'Agostino RB, Cohen RJ, Hohnloser SH. Predictive value of T-wave alternans for arrhythmic events in patients with congestive heart failure. Lancet. 2000;356:651-2.

7.             Adachi K, Ohnishi Y, Shima T, Yamashiro K, Takei A, Tamura N, Yokoyama M. Determinant of microvolt-level T-wave alternans in patients with dilated cardiomyopathy. J Am Coll Cardiol. 1999;34:374-80.