Electrophysiological Study Characteristics in Patients With and Without Ebstein Anomaly With Accessory Pathway

Abstract

Background: Ebstein's anomaly (EA) is a life-threatening rhythm disturbance, which is not frequent early in life. Symptomatic patients are well treated with radiofrequency catheter ablation. Objectives: We assessed the prevalence, history and treatment of arrhythmias, in particular pre-excitation and Wol-Parkinson-White (WPW) syndrome to provide a guide for ablation according to the results of electrophysiology study (EPS) and electrocardiogram (ECG) in patients with and without EA. PatientsandMethods: Forty-five patients with and without EA with accessory pathway had referred to our tertiary research center be- tween 2004 and 2010. The two groups underwent 12 lead ECG at rest and QRS duration, PR interval, P wave amplitude, and all arrhythmia accidents and diagnostic pre-stimulation factors were measured. The EPS were performed and the reports were determined according A-H interval, H-V interval, and maximum delta to peak R, PR/Max delta to peak R before and after ablation. Results: Fifty-four patients were enrolled (29 cases with EA (60% male; mean age: 29.07 12.3; P > 0.05)). Out of 29 cases with EA, 51.7% had pre-excitation (WPW), which were included in our study and the remaining had EA without Wol-Parkinson-Wh ite (WPW). Wol-Parkinson-Wh ite was diagnosed in all patients without anomaly. Mean amplitude of P wave in patients with and without EA were 0.14 0.07 and 0.10 0.03, respectively (P = 0.04). The PR interval before and after ablation in patients with and without Ebstein anomaly was 104.53 23.91 and 182.67 41.5, respectively (P < 0.05). The QRS mean after ablation in EA and non-EA in both groups was 131.53 29.7 and 100 16.8, respectively (P < 0.05). A-H interval mean before and after ablation in EA and non EA were 101.93 vs.79.68 and 111.53 39.58, and 79.68 21.7 vs. 81.36 20 respectively, however after the ablation the results were statistically significant (P = 0.01). Regarding accessory pathway in EA and non-EA; 73.3% and 84% had right posteroseptal AP; 6.66% and 12% had right anteroseptal AP; 13.3% and 4% had right free wall AP. Conclusion: In EA patients with accessory pathway, the most common location was right posterolateral. Comparison of the EPS be- tween cases with and without anomaly showed no significant relationship regarding most of the EPS criteria. Since EA patients have a high potential for developing tachyarrhythmias, which is the most prevalent reason for death; diagnosis and treatment of those pa- tients is critical.