The relationship between serial postinfarction T wave changes and infarct size and ventricular function as determined by cardiac magnetic resonance imaging.

ABSTRACT

BACKGROUND: The value of sequential T wave changes on the electrocardiogram (ECG) has less well been described than ST-segment changes in the follow-up of patients with myocardial infarction (MI). We investigated whether the amplitude of T wave positivity correlates with infarct size (IS) and left ventricular ejection fraction (LVEF) measured using cardiac magnetic resonance imaging 3 months after reperfusion therapy. MATERIALS AND METHODS: Fifty-five patients with a first acute MI referred for primary percutaneous coronary intervention were included. Electrocardiograms were analyzed within 4 hours after reperfusion and at 3 months, measuring T wave ampitudes in 2 contiguous infarct-related leads, summed up as one value called T wave amplitude. Cardiac magnetic resonance imaging was performed at 3 months of follow-up. Correlations between T wave amplitude, IS, and LVEF were tested with Pearson r correlation coefficient test. Subanalyses were performed using a 2-sample t test. RESULTS: A good correlation was found between LVEF and IS (r = -0.7, P < .0001). Most of the patients had inferior MI location (69%). In this group, there were significant positive correlations between the amount of T wave positivity and both IS (r = -0.40, P = .012) and LVEF (r = 0.33, P = .043). Results were similar in patients with and without an increase in T wave amplitude during follow-up. CONCLUSIONS: In this study of patients with reperfused MI, patients with inferior locations demonstrated a statistically significant relationship between the amount of positivity of T wave amplitude and both IS and LVEF measured at 3 months. Furthermore, these results were independent of whether the T wave positivity was persistent or evolutionary between the immediate postreperfusion and 3-month ECG recordings.