EFFECT OF INTRACORONARY BALLOON INFLATION AT PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY ON QT DISPERSION

Background QT dispersion (QTd) has recently been used as a marker for arrhythmic death caused by adverse drug effect. However, the effect of acute ischemia on QTd is not well described. Methods To determine the effect of acute ischemia on QTd, 12-lead electrocardiograms were obta ined at baseline and 2 minutes after intracoronary balloon inflation i n 34 patients. QTd was calculated as a range between shortest (QTmin) and longest (QTmax) QT intervals. Results In 18 patients balloon infla tion provoked ST elevation, increased QTd (43 +/- 20 msec to 61 +/- 19 msec, p = 0.012), and decreased QTmin (390 +/- 43 msec to 361 +/- 43 msec, p < 0.001) without significant effect on QTmax (433 +/- 42 msec to 423 +/- 47 msec). No significant changes in QT measures were observ ed in eight patients who had ST depression and in eight without ST cha nges. Conclusion Acute transmural ischemia provoked by intracoronary b alloon inflation increases QTd by reducing the QTmin interval, which m ay modify the electrophysiologic substrate.