Microvolt T-wave alternans testing for ventricular arrhythmia risk stratification

Extensive research and clinical interest has focused recently on use of microvolt T-wave alternans (MTWA) as a means for sudden death risk stratification in patients with cardiomyopathy. Emphasis has been placed on determining whether MTWA testing can more accurately identify high-risk patients from the broad population who are potentially eligible for prophylactic implantable cardioverter defibrillators. More recent studies seek to determine if additional patients not currently covered by primary prevention implantable cardioverter defibrillator guidelines could be defined using MTWA. Unfortunately, accumulation of clinical data has not necessarily led to clarity in the minds of the end-users as to the role of MTWA in clinical practice. This article serves to provide background information, selective review of relevant studies, and a perspective on where the field stands today. A general framework for incorporating MTWA into clinical practice is presented.