[QT-dispersion in the surface ECG as a parameter of increased electrical vulnerability in acute myocardial ischemia]

QT-dispersion defined as the difference between QTmax and QTmin in the 12-lead surface ECG was determined in 33 patients with acute myocardial infarction treated by intravenous thrombolysis. In 11 patients, ventricular fibrillation ensured during the first 24 h after hospital admission. These patients were then compared with 22 matching infarction patients without malignant ventricular rhythm disturbances. QT-dispersion as evaluated in the first ECG taken after hospital admission was significantly higher in patients with (88 +/- 16 ms) compared to QT-dispersion in patients without ventricular fibrillation (66 +/- 19 ms; p < 0.001). When QT-dispersion was again assessed in ECG tracings recorded prior to hospital discharge, it was markedly reduced, with no significant difference between either patient group (53 +/- 16 ms versus 54 +/- 18 ms). These results indicate that QT-dispersion in the surface ECG represents a marker of inhomogeneous repolarization in patients with acute myocardial infarction prone to ventricular fibrillation. This may allow early identification of high-risk patients soon after hospital admission.