Value of microvolt T-wave alternans for predicting patients who would benefit from implantable cardioverter-defibrillator therapy.

Despite considerable progress in the management of coronary artery disease and dilated cardiomyopathy, a substantial proportion of patients remains at the risk of life-threatening arrhythmic events. The Multicenter Automatic Defibrillator Implantation II and Sudden Cardiac Death Heart Failure studies have conclusively demonstrated that prophylactic implantable cardioverter-defibrillator (ICD) therapy reduces mortality among subjects with ischemic and nonischemic cardiomyopathy but at the expense of potentially unnecessary ICD implantation in a large percentage of patients. Microvolt T-wave alternans (MTWA), with a negative predictive value greater than 90%, holds promise for selecting the patients who would likely and patients not likely to benefit from ICD implantation. Accurate identification of high-risk patients by noninvasive MTWA may allow for improved widespread screening for sudden death prevention in the general population.