QT Dispersion: Does It Change after Percutaneous Coronary Intervention?

BACKGROUND: Myocardial ischemia is one of several causes of prolonged QT dispersion. The aim of this study was to evaluate the effect that percutaneous coronary intervention has on the depolarization and repolarization parameters of surface electrocardiography in patients with chronic stable angina. METHODS: We assessed the effects of full revascularization in patients with chronic stable angina and single-vessel disease who underwent percutaneous coronary intervention. Twelve-lead electrocardiograms were recorded before intervention and 24 hours subsequently. We measured parameters including QRS duration, QT and corrected QT durations, and JT and corrected JT duration in both electrocardiograms and compared the values. RESULTS: There were significant differences between the mean QRS interval (0.086 ± 0.01 sec vs. 0.082 ± 0.01 second; p value = 0.01), mean corrected QT dispersion (0.080 ± 0.04 sec vs. 0.068 ± 0.04 sec; p value = 0.001), and mean corrected JT dispersion (0.074 ± 0.04 sec vs. 0.063 ± 0.04 sec; p value = 0.001) before and after percutaneous coronary intervention. No significant differences were found between the other ECG parameters. CONCLUSION: Our data indicate that the shortening of corrected QT dispersion and corrected JT dispersion in patients undergoing percutaneous coronary intervention is prominent.

Heart and athlete.

Regular participation in intensive physical exercise is associated with electro-morphological changes in the heart. This benign process is called athlete's heart. Athlete's heart resembles few pathologic conditions in some aspects. So differentiation of these conditions is very important which otherwise may lead to a catastrophic event such as sudden death. The most common causes of sudden death in young athletes are cardiomyopathies, congenital coronary anomalies, and ion channelopathies. The appropriate screening strategy to prevent sudden cardiac death in athletes remains a challenging issue. The purpose of this review is to describe the characteristics of athlete's heart and demonstrate how to differentiate it from pathologic conditions that can cause sudden death.