EFFECT OF CORONARY ANGIOPLASTY ON QT DISPERSION

Increased QT dispersion (QT(max) - QT(min) [QTd]) reflects inhomogeneo us ventricular repolarization that may provide a substrate for serious arrhythmias and is associated with adverse clinical outcomes in patie nts with heart disease, Effective treatment of acute myocardial infarc tion or ventricular arrhythmias may reduce QTd, but the effect of coro nary revascularization on QTd in patients without these conditions is unknown. In this study, QTd was measured before and 4 and 24 hours aft er successful angioplasty in 94 patients without ongoing symptomatic m yocardial ischemia or malignant arrhythmias. QTd decreased from 434 +/ - 17 msec before angioplasty to 354 +/- 15 msec 4 hours (p < 0.05) and 33 +/- 14 msec 24 hours after angioplasty (p < 0.05). QTd was improve d in 64% of patients, worse in 28%, and unchanged in 8%, Thus angiopla sty significantly improves QTd. This may reflect increased myocardial perfusion and may be inherently beneficial by reducing the propensity for arrhythmias.