The microvolt T-wave alternans test

Several clinical parameters and noninvasive tests have been developed to identify patients under the risk for sudden cardiac death (SCD). The microvolt T-wave alternans (MTWA) test is a noninvasive diagnostic method based on the measurement of subtle (microvolt) beat-to-beat alternation of the T-wave on the surface electrocardiogram and used for risk stratification of patients under the risk for SCD. Studies in the last decade have shown that the MTWA test is an effective method to distinguish patients with a high risk for arrhythmogenic mortality among patients suffering ischemic or nonischemic cardiomyopathies or with a history of myocardial infarction, with a high negative predictive value. This review revisits the MTWA test in the light of the most recent clinical studies.