Abstract 18949: Post-Extrasystolic T-Wave Change Predicts Mortality in Survivors of Myocardial Infarction

Abstract

Background: The T-wave of the first normal beat after a ventricular premature complex (VPC) often differs in shape in terms of a change in the T-wave amplitude or in the direction of the T-wave vector. The phenomenon of post-extrasystolic T-wave change (PEST) was first reported by White in 1915 and confirmed in many clinical and experimental studies. However, PEST has not led to a meaningful clinical application. In this study, we tested whether PEST provides prognostic information in contemporarily treated post-MI patients. Methods and Results: 941 consecutive patients (mean age 61 years, 19% female) presenting with acute MI were enrolled between May 2000 and March 2005. All patients underwent 30-minute recordings of high resolution ECG (1.6 kHz sampling of orthogonal XYZ leads). 224 patients showed VPCs during the 30-minutes. We quantified PEST by two variables (1) change in T-wave area and (2) change in the angle of the T-wave vector in each case compared to the average of three T-waves before and after the first post-extrasysolic beat. PEST was defined as ratio TPEST/T±3 area <1 and ratio TPEST/T±3 angle ≥ 5°. PEST was present in 63 of the 224 patients. Primary endpoint was total mortality during a follow-up period of five years. Uni- and multivariable analyses were performed with traditional risk stratifiers like LVEF ≤ 35%, GRACE score ≥ 120 points and VPC count ≥ 5 per 30 minutes. During the follow-up, 26 of the patients died. PEST shows the strongest association with mortality in the univariable analysis followed by GRACE score, frequent VPCs and reduced LVEF In the multivariable analysis only PEST and GRACE score were independent predictors of mortality (see table). Conclusions: PEST is significantly associated with mortality in survivors of an acute myocardial infarction, and is independent of standard risk predictors. We assume that PEST might becaused by abnormal transmural gradients in action potential duration.