Common and distinctive electrocardiographic characteristics and effective catheter ablation of idiopathic ventricular arrhythmias originating from different areas of ventricular septum adjacent to atrioventricular annulus

Objective To investigate electrocardiographic (ECG) characteristics and radiofrequency catheter ablation (RFCA) efficacy for premature ventricular complexes (PVCs) and idiopathic ventricular tachycardias (IVTs) originating from ventricular septum areas adjacent to atrioventricular annulus (VS‐AVA). Methods Among 1,505 consecutive PVCs/IVTs cases, 106 (7.04%) were confirmed as origin of VS‐AVA guided by both fluoroscopy and three‐dimensional mapping system during RFCA. Characteristics of surface 12‐lead ECG were analyzed. Results The overall success rate for RFCA of PVCs/IVTs originating from VS‐AVA was 82.08% (87/106), common ECG characteristics were: mainly positive R wave on lead I; dominant‐positive R on aVL (91/106, 85.85%) for most, r (1/106, 0.94%) or qr (14/106, 13.21%) in few; QS or qs on aVR; and decreasing R wave amplitude and increasing S wave depth on II, III, and aVF from superior to inferior septum; and S wave on at least one inferior lead (generally III). Distinctive ECG features were: precordial transition zone before or after V2 for septum adjacent to mitral (MA, 19/19, 100.0%) or tricuspid (TA, 74/87,85.05%) annulus origin; initial r wave and rS on V1 for superior septum near TA (above His bundle) origin (9/10, 90.0%) with no initial r wave for most other origins; and QS on V1 for mid‐inferior septum near TA origin (73/77, 94.81%) and QR (Qr, qR or qr) on V1 for septum near MA origin (17/19, 89.47%). Conclusion Distinctive ECG characteristics of PVCs/IVTs originating from VS‐AVA aid in origin localization guiding effective RFCA.