QT DISPERSION AND MORTALITY AFTER MYOCARDIAL-INFARCTION

QT dispersion may serve as a measure of variability in ventricular rec overy time and may be a means of identifying patients at risk of arrhy thmias and sudden death after acute myocardial infarction. We investig ated this possibility on electrocardiograms (ECGs) recorded 2 or 3 day s after infarction (early) and at least 4 weeks later (late). 163 pati ents who died between 1 day and 5 years after infarct were compared wi th an equal number of survivors matched for age and sex. 53 of the pat ients who died and 82 survivors also had late ECGs. There was no diffe rence in early QT dispersion between the patients who died and the sur vivors (mean QT(c) dispersion 112.1 [SD 44.4] vs 109.9 [42.7] ms(1/2)) . QT(c) dispersion fell significantly from early to late ECGs in survi vors (110.9 [48.5] to 76.5 [28.8] ms(1/2)), but not in patients who di ed during follow-up (108.0 [51.0] to 98.9 [43.1] ms(1/2)). The differe nce between the groups in the mean change was significant (34.4 [55.2] vs 9.1 [60.8] ms(1/2), p=0.016). QT dispersion measured on an ECG rec orded 2 or 3 days after acute myocardial infarction does not predict m ortality during the next 5 years. Increased QT dispersion on ECGs reco rded at least 4 weeks after infarct may be associated with subsequent mortality, but this finding must be confirmed in a prospective trial.