QT inteival and QT dispersion in patients with previous myocardial infarction

The aim of the study was to determine the incidence of long QT interval, QT dispersion and their relation in patients with previous myocardial infarction. Sixty patients with previous myocardial infarction based on a history of prolonged chest pain, ECG changes and/or elevated cardiac enzymes were included in this study. It was found that the patients had mean QT less than or equal to 0.44 sec. and no patient had prolonged QT interval. Abnormal QTc more than 0.44 sec. was found in 12 patients. The mean value of QTc was 0.47 to 0.44 sec. 52% of the patients had normal QT dispersion and the remaining 48% had abnormal QT dispersion. A nonsignificant correlation was detected between QTc and QT dispersion