Idiopathic ventricular arrhythmia originating from the para‐Hisian area: Prevalence, electrocardiographic and electrophysiological characteristics

Abstract

Abstract Background We investigated the prevalence and the electrocardiographic and electrophysiological characteristics of ventricular arrhythmias (VAs) originating from the para‐Hisian area. Methods Among 250 patients with idiopathic VAs, 8 (3.2%) had an ablation site in the para‐Hisian region. For comparison with right ventricular (RV) para‐Hisian VAs ( n =6), 27 patients with VAs originating from the posterior RV outflow tract (RVOT) were studied. Results Para‐Hisian VAs had an R wave in leads I and aVL. The VAs originating from the site below the His bundle region were determined to have a superior axis ( n =4, 50%). A His potential was recorded at the proximal bipole of the successful ablation site in 6 patients. RV para‐Hisian VAs had a narrower QRS width (114±12 ms vs. 139±12 ms, P =0.003), as well as a higher incidence of R waves in lead aVL (83.3% vs. 0%, P <0.001) and QS waves in lead V 1 (83.3% vs. 22.2%, P =0.004) compared to posterior RVOT VAs. A greater R wave amplitude in lead I (1.15±0.34 mV vs. 0.34±0.18 mV, P =0.001) and a smaller R wave amplitude in the inferior leads (0.68±0.23 mV vs. 1.58±0.55 mV, P <0.001), with a higher R wave amplitude ratio in leads II/III (4.2±2.0 vs. 1.1±0.2, P =0.01) were the major ECG characteristics. Conclusions Para‐Hisian VAs have distinctive electrocardiographic features and can be successfully eliminated without disturbance of atrioventricular conduction.