T wave positivity in resting electrocardiogram predicts preserved systolic thickening in chronic anterior Q wave myocardial infarction: an echocardiographic study.

AIM

After ST elevation myocardial infarction, ST segment and T wave changes generally resolve, but in some patients T waves keep their negative components for a long time. The aim of this study is to evaluate the pathophysiological implications of persistent negative T waves and restored positive T waves in the chronic stage of Q wave myocardial infarction.

METHODS

We studied 30 patients with a previous anterior wall ST elevation myocardial infarction (more than one year follow-up) and presenting Q waves in at least three consecutive precordial leads in the standard 12-lead electrocardiogram at rest. Patients were divided into two groups according to the T wave pattern in leads with Q waves: positive T group consisting of patients in whom all T wave components showed an upright configuration; and a negative T group consisting of patients in whom T waves were are least partly inverted. We used echocardiography to measure systolic thickening of the interventricular septum within the infarction area. Systolic thickening was considered significant when end-systolic thickness was greater than end-diastolic thickness by > 25% in proportion and > 1 mm in absolute value.

RESULTS

Significant systolic thickening was demonstrated in 14 (74%) of the 19 positive T patients and in one (9%) of the 11 negative T patients (odds ratio 8.1; 95% CI, 1.2 to 53.5; p = 0.002).

CONCLUSION

In the chronic stage of a myocardial infarction, restored T wave positivity predicts preserved systolic thickening, suggesting the presence of viable and normally contracting myocytes within the infarction area. Further studies are needed to establish the prognostic value of T wave characteristics in patients with a past history of myocardial infarction.