Relationship between rate-corrected QT interval and wall motion abnormalities in the setting of acute myocardial infarction.

We studied 108 patients (73 men and 35 women, mean age of 63.1 +/- 11.2 years) with Q-wave acute myocardial infarction (anterior -52, inferior -41, and combined anteroinferior -15) 4 days after infarct onset to determine whether any correlation exists between rate-corrected QT interval (QTc) and functional infarct size, expressed as wall motion index. QTc was calculated by Hodges' linear algorithm [QT + (1.75 x heart rate - 60)]. Wall motion index was determined using a 16-segments model, as recommended by the American Society of Echocardiography. Wall motion index was significantly higher in anterior and in combined infarctions. QTc was shortest in inferior infarction. There was a statistically significant overall correlation between wall motion index and QTc (r = 0.83, p < 0.001). The relationship was weakest in inferior infarction. In conclusion, prolonged QTc may be implicated as an additional marker of left ventricular dysfunction in patients with acute anterior and combined anteroinferior myocardial infarction.