Value of QT dispersion in diagnosis of restenosis after intracoronary stent implantation

We studied the ECGs of patients with single vessel disease before and after (long term) coronary stent implantation. The interlead variability of the QT interval, known as QT dispersion (QTd), is believed to reflect the regio nal variations in ventricular repolarization and, thus, may provide an indi rect marker of arrhythmogenicity. There are no reliable noninvasive markers of significant restenosis after stent implantation. The effect of coronary revascularization on QTd in patients who underwent coronary stenting has n ot been investigated extensively. The aim of this study was to evaluate the value of QTd in predicting restenosis after intracoronary stent implantati on. QTd with 12 lead surface ECG was measured in 48 patients (21 with reste nosis and 27 without restenosis; 33 male; mean age, 58 +/- 10.8 years) befo re the procedure and after long-term follow-up (mean, 6.8 +/- 3.2 months). All patients had coronary angiographic control at the end of the follow-up period. QTd (as the difference between the maximum and minimum QT interval measured from 12 lead EGG) and rate-corrected QT (QTcd) were evaluated at r est. In 27 patients without restenosis, QTd and QTcd decreased from 58 +/- 14.4 and 62.8 +/- 20.4 ms to 26.3 +/- 9.2 and 29.6 +/- 10.6 ms in the long term follow-up, respectively (P < 0.001). However, in 21 patients with rest enosis, there was no significant change in QTd and QTcd intervals and they were still increased at the end of the long-term follow-up (P > 0.05). In c onclusion, increased QT interval dispersion may be an inexpensive and simpl e marker of restenosis after intracoronary stent implantation. (C) 1999 Els evier Science Ireland Ltd. All rights reserved.