Utility of T-wave alternans in congestive heart failure

The use of implantable cardioverter defibrillator (ICD) in heart failure patients decreases the arrhythmic mortality with the cost of increasing the number of patients to be treated, and microvolt T-wave alternans (MTWA) testing can be used as a good criteria to better select the candidate for such a therapy. This article examines generalities about the mechanism of alternans, definitions of positive, negative, and indeterminate MTWA tests, and factors that can modify these results. We review clinical studies that have found MTWA as a marker of ventricular arrhythmias in patients with heart failure, independent of etiology, ischemic or idiopathic. Microvolt T-wave alternans permits the selection of low risk patients who may not benefit of ICD implantation by standard criteria, due to high negative predictive values in most studies.