Intravenous Nicorandil Can Reduce QT Dispersion and Prevent Bradyarrhythmia During Percutaneous Transluminal Coronary Angioplasty of the Right Coronary Artery

BACKGROUND: Nicorandil, a potassium channel opener, is used for the treatment of angina pectoris and has a pharmacologic preconditioning effect. This study evaluated whether intravenous nicorandil reduces QT dispersion and prevents bradyarrhythmia during percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery. METHODS: A historical cohort study on the effect of nicorandil on QT dispersion and bradyarrhythmia was conducted. Fifty patients who underwent PTCA of the right coronary artery were enrolled. The patients were divided into a nicorandil (n = 25) group and control group (n = 25). Nicorandil was injected at 4 mg/h continuously 1 hour before PTCA in the nicorandil group. QT dispersion was measured at 1 hour before PTCA (baseline), immediately before PTCA, and 1 minute after the initiation of the first balloon inflation. RESULTS: QT dispersion at 1 minute after the initiation of the first balloon inflation in the control group increased significantly (QT dispersion: 37.1 +/- 17.8 msec and 21.7 +/- 12.2 msec, respectively, P < .001 vs baseline in the control group), and this was larger than at 1 minute after the initiation of the first balloon inflation in the nicorandil group (QT dispersion: 37.1 +/- 17.8 msec and 20.8 +/- 9.4 msec, respectively, P < .001). By two-way repeated measures analysis of variance, there were significant interactions between the time factor and the grouping factor in QT dispersion (P < .001). Bradyarrhythmia was observed in 6 patients in the control group, but none was observed in the nicorandil group. CONCLUSIONS: Intravenous nicorandil reduces QT dispersion and prevents bradyarrhythmia during PTCA of the right coronary artery.