QT dispersion before and after coronary artery angioplasty: a case study from Iran

In this study, we investigated the changes in QT dispersion (QTd) after successful coronary artery revascularization.

QTd, as a marker of regional variability of myocardial repolarization, increases following impaired myocardial perfusion and is associated with increased risk of ischemia-induced arrhythmia.

In 45 consecutive patients (mean age 54.39±11.49 years) undergoing elective percutaneous coronary intervention (PCI), QTd was measured from a 12-lead electrocardiogram 6-12 hours before and 6 hours after the procedure. QTd was defined as the difference between maximum and minimum QT interval in the 12 leads. QT changes were analyzed regarding preoperative ejection fraction (EF), type and number of involved vessels, type and number of revascularized coronary arteries and history of Q-wave MI using SPSS software.

QTd significantly decreased postoperatively from 55.48±20.03 to 42.00±19.96 in the study population (P=0.001). Subgroup analyses showed that QTd did not decrease significantly in patients with two-vessel disease and those with low EF (<50%); however, the reduction was significant for other subgroups.

Successful PCI results in improved regional heterogeneity of myocardial repolarization, evidenced as decreased QTd after the procedure.