Risk Stratification Tests for Determining Arrhythmias (Signal-Averaged Electrocardiography [SAECG] and Microvolt T-Wave Alternans [MTWA])

This policy covers risk‑stratification testing for ventricular arrhythmias using microvolt T‑wave alternans (MTWA) and signal‑averaged ECG (SAECG), with MTWA considered medically necessary for assessing risk of fatal ventricular arrhythmias and sudden cardiac death in patients at risk (e.g., prior myocardial infarction, congestive heart failure, cardiomyopathy, or unexplained syncope) and to help identify candidates for further electrophysiology testing or ICD consideration. SAECG is acceptable for arrhythmia risk stratification in select situations but is not medically necessary after prior MI and is investigational or unproven for many uses (including cardiomyopathy, syncope, post‑surgical or transplant assessment); MTWA requires specialized sensors and heart‑rate elevation (>110 bpm) and has limited evidence to definitively guide therapy beyond the listed indications.

"Microvolt T-wave alternans (MTWA) is medically necessary as a risk‑stratification technique for primary or secondary prevention of fatal ventricular arrhythmias and sudden cardiac death in patients..."