Evaluation of P Wave Dispersion, QT Dispersion and P Wave Amplitude in Patients with Obstructive Sleep Apnea Syndrome

Objective The purpose of the study is to evaluate the risks of atrial and ventricular tachyarrhythmia and the risk of right atrial dilatation by using P wave amplitude (Pda) measurement, in patients with Obstructive Sleep Apnea syndrome (OSAS) by using the parameters of the P wave dispersion (Pd) and QT interval dispersion (QTc) the accepted non-invasive risk indicators for atrial and ventricular tachyarrhythmia. Materials and Methods Patients who had applied to our clinic’s sleep laboratory with pre-diognosis of OSAS were evaluated. Two hundred twenty five cases were included in the study who met the criteria for acceptance to work. Polysomnographic tests and routine blood tests applied to all patients. In addition, electrocardiography was performed. Pd, QTc and corrected QT dispersion (QTcd) calculated on a 12 lead surface electrocardiographic examination. The difference between patient and control groups were evaluated. Results After polysomnographic workup, 56 cases with apnea-hypopnea index (AHI) <5 were included as the control group and 169 cases with AHI ≥5 were included as the patient group. The mean age determined as 48.3±8.9. There was no statistically significant differences between patient and control group with regard to QTcmin, QTcmax, QTd and QTcd parameters (p>0.05). Although QTcd was higher than normal range in patient group, the differences was not significant compared to control group (p>0.05). In the studies made for P wave, although the values in terms of Pmax, Pmin and Pd were found higher in the patient group than in the control group, a significant difference was not determined between the groups. However, P wave amplitude was significantly higher as statistically in the patient group than in the control group (p=0.02). Conclusion Pd and QTc/QTcd parameters do not seem to be appropriate for the assessment of ventricular and atrial arrhythmia risk in patients with OSAS. However, the increase in Pda may be indicative of an increased risk of right atrial dilatation. There is a need for forward studies involving large case series in order to provide clarity on the subject.