Incidence of T wave alternation after acute myocardial infarction and correlation with other prognostic parameters: Results of a prospective study

Tachycardia induced alternation of the T wave (TWA) has been associated wit h arrhythmia morbidity in mixed patient populations. However, less is known concerning the general incidence of TWA and its usefulness in risk stratif ication early after acute myocardial infarction (MI). TWA was prospectively and systematically assessed in 240 consecutive patients 15 +/- 6 days afte r acute MI and prior to discharge. Results of TWA measurements were compare d to other noninvasive risk markers, LV function, and coronary angiography. Sustained TWA was present at rest or inducible during exercise in 27% of p atients. The patient-specific heart rate for the onset of TWA was 48 +/- 9 beats/min. After multivariate analysis, TWA correlated with age (P = 0.02) and LV function (P = 0.002) and occurred more often in patients after nonan terior MI (P = 0.03). Acute results of Holter monitoring, late potentials b y signal-averaged EGG, and heart rate variability were unrelated to the TWA status. During follow-up (452 +/- 210 days) two major arrhythmic events oc curred. The incidence of TWA early after MI is about 25%. TWA is related to age and LV function but not to other common arrhythmia markers. Although T WA does not appear to be related to excessive cardiac morbidity, evaluation of the prognostic significance of TWA requires further study.