The recommended delay to ICD therapy in this setting stems from the results of DINAMIT (Defibrillator in Acute Myocardial Infarction Trial), in which defibrillator implantation 6 to 40 days after MI in patients with EF 0.35 and impaired cardiac autonomic function was not shown to reduce overall cardiac death risk. The observed reduction in arrhythmic deaths was offset by a relative increase in the numbers of nonarrhythmic The IRIS (Immediate Risk Stratification Improves also showed that early ICD therapy in patients with LVEF 0.40 and a high heart rate, nonsustained VT regardless of LVEF, or both did not result in improved survival. The utility of a wearable cardioverter-defibrillator in high-risk patients during the first 4 to 6 weeks after STEMI is under investigation http://clinicaltrials.gov/ct2/show/ NCT00628966). The indications for ICD therapy 40 days after STEMI are based on LVEF and New York Heart Association class, as derived from the results of the landmark MADIT 2 (Multicenter Automatic Defibrillator Implantation Trial 2) and SCDHeFT (Sudden Cardiac Death in Heart Failure) tri- If LVEF remains 0.35 and the patient has New York Heart Association class II or III HF symptoms, or if the LVEF is 0.30 independent of symptoms, then ICD implanta- tion is recommended.496 Indications for cardiac resynchroniza- tion therapy in the late, convalescent phase of STEMI include residual LV function, NewYork Heart Association class, QRS duration, and LBBB morphology.592 In addition to determination of LVEF, several other non- invasive strategies have been proposed to identify patients at high risk for arrhythmic events after STEMI, such as sig- nal-averaged or high-resolution ECG, heart rate variability, baroreflex sensitivity, and T-wave alternans.591 These strate- gies have not been adopted widely because of their limited O Gara et al 2013 ACCF/AHA STEMI Guideline e399 performance characteristics and are not recommended for routine use. 11. 