The effects of obstructive sleep apnea in patients with coronary artery disease on QT dispersion, T peak to T end indices

Introduction: Obstructive sleep apnea (OSA) is the most common sleep-breathing disorder. OSA is associated with cardiovascular diseases such as coronary artery disease (CAD) and arrhythmias with an increased risk of sudden cardiac death. Some changes in ECG markers are seen as an indicator of arrhythmogenicity, especially ventricular arrhythmias. The goal of this study was to investigate if OSA patients with CAD have QT dispersion and T peak to T end (TpTe) changes as a surrogate of arrhythmogenicity. Methods: We studied 75 patients with CAD who underwent polysomnographic studies. Patients were categorized into mild, moderate, and severe OSA according to the Apnea hypopnea index (AHI). Baseline ECG and echocardiography for assessing LV function and valvular heart disease were done for all of them. Results: Results showed that in patients with moderate and severe sleep apnea QT dispersion was higher in a group with more involvement of coronary artery disease, reduced ejection fraction, and a history of old MI. However, we didn’t find any significant statistical relationship between OSA and TpTe marker. Conclusion: Our results showed a positive relation between ECG arrhythmic indices such as QT dispersion and OSA severity in patients with CAD.