Correlation of QT Dispersion in Patients with Acute Myocardial Infarction and Reperfusion Arrhythmias Following Primary Percutaneous Coronary Intervention: A Prospective Study

Abstract Background: Reperfusion arrhythmias are commonly encountered following primary percutaneous coronary intervention (PPCI) in patients with acute myocardial infarction (AMI). QT dispersion (QTd) and corrected QTd (cQTd) are noninvasive electrocardiographic markers reflecting heterogeneity of ventricular repolarization and may serve as predictors of electrical instability and arrhythmic risk following reperfusion. Objectives: The objective of this study was to evaluate the association between QTd and reperfusion arrhythmias following PPCI in patients with AMI, and to assess the temporal changes in QTd and cQTd after reperfusion. Materials and Methods: This prospective observational study included 125 patients with AMI undergoing PPCI. Standard 12-lead electrocardiograms were recorded at admission, immediately after PPCI, and at discharge for measurement of QTd and cQTd. Continuous Holter monitoring was used to identify reperfusion arrhythmias, which were categorized as major or minor arrhythmias. Clinical, electrocardiographic, and angiographic parameters were analyzed for association with QTd and cQTd values. Results: Frequent premature ventricular complexes were the most common reperfusion arrhythmia (44.8%), followed by accelerated idioventricular rhythm (15.2%) and nonsustained ventricular tachycardia (12.8%). Receiver-operating characteristic curve analysis revealed that corrected QTd at discharge had moderate predictive ability for major reperfusion arrhythmias with an area under the curve of 0.648. A cutoff value of 69.49 ms yielded a sensitivity of 43.5% and specificity of 87.3% for predicting major arrhythmias. Both QTd and cQTd demonstrated a progressive decline from admission to discharge following PPCI. Mean cQTd decreased from 114.09 ms at admission to 80.52 ms post-PPCI and 58.18 ms at discharge. Patients with major reperfusion arrhythmias had significantly higher cQTd values at admission (130.76 ± 41.64 ms vs 110.33 ± 24.18 ms; P = 0.032), post-PPCI (93.75 ± 29.59 ms vs 77.50 ± 16.94 ms; P = 0.0175), and discharge (66.62 ± 18.89 ms vs. 56.27 ± 11.30 ms; P = 0.018) compared to patients with minor arrhythmias. Increasing Killip class was associated with progressively higher discharge cQTd values. Smokers also demonstrated significantly higher discharge cQTd values compared to nonsmokers ( P = 0.0061). Conclusion: QTd and corrected QTd significantly decrease following successful reperfusion with PPCI. Elevated cQTd values were associated with major reperfusion arrhythmias, suggesting that cQTd may serve as a useful noninvasive marker for predicting arrhythmic risk following PPCI in AMI patients. Increased cQTd was also associated with greater clinical severity as reflected by higher Killip class.