Electrocardiographic evolutionary changes and left ventricular remodeling after acute myocardial infarction - Results of the GISSI-3 Echo substudy

OBJECTIVE The aim of this study was to describe the electrocardiographic (ECG) evolutionary changes after an acute myocardial infarction (AMT) and to evaluate their correlation with left ventricular function and remodeling. BACKGROUND The QRS complex changes after AMT have been correlated with infarct size and left ventricular function. By contrast, the significance of T wave changes is controversial. METHODS We studied 536 patients enrolled in the GISSI-3 Echo substudy who underwent ECG and echocardiographic studies at 24 to 48 h (S1), at hospital discharge (S2), at six weeks (S3) and six months (S4) after AMI. RESULTS The number of Q waves (nQ) and QRS quantitative score (QRSs) did not change over time. From S2 to S4, the number of negative T waves (nT NEG) decreased (p < 0.0001), wall motion abnormalities (%WMA) improved (p < 0.001), ventricular volumes increased (p < 0.0001) while ejection fraction remained stable. According to the T wave changes after hospital discharge, patients were divided into four groups: stable positive T waves (group 1, n = 35), patients who showed a decrease greater than or equal to 1 in nT NEG (group 2, n = 361), patients with no change in nT NEG (group 3, n = 64) and those with an increase greater than or equal to 1 in nT NEG (group 4, n = 76). The QRSs and nQ remained stable in all groups. Groups 3 and 4 showed less recovery in %WMA, more pronounced ventricular enlargement and progressive decline in ejection fraction than groups 1 and 2 (interaction time x groups p < 0.0001). CONCLUSIONS The analysis of serial ECG can predict postinfarct left ventricular remodeling. Normalization of negative T waves during the follow-up appears more strictly related to recovery of regional dysfunction than QRS changes. Lack of resolution and late appearance of new negative T predict unfavorable remodeling with progressive deterioration of ventricular function. CT Am (C) 1999 by the American College of Cardiology.