To explore the electrocardiographic characteristics of patients with idiopathic ventricular arrhythmias (VAs) originating from different portions of distal great cardiac veins (DGCV).

The study included 49 patients underwent successful RFCA of premature ventricular complex(PVCs)/ventricular tachycardia(VT) from different portions of the DGCV in our department from July 2009 to March 2016. The surface 12-lead electrocardiogram (ECG) and intraventricular ablation mapping features were analyzed. Patients were divided into four groups according to the mapping and ablation results: DGCV1(10 patients), DGCV2 (13 patients), proximalanterior interventricular vein (PAIV, 17 patients)and extend distal great cardiac vein (EDGCV, 9 patients). We analyzed the similarities and differences between surface 12-lead ECG of patients with PVCs/VT from different portions of DGCV, and compared with random chosen 290 patients with PVCs/VT from ventricular outflow tract and adjacent structure.

A positive R wave in inferior leads, a negative QS morphology in lead aVL and aVR were found among all groups. The different characteristics of surface 12-lead ECG of VAs originating from DGCV were as follows: (1)EDGCV patients demonstrated a positive R or r wave on lead Ⅰ(6/9) while a negative rS or qr wave was evidenced in other three groups (39/40). (2)A positive R pattern on lead V₁, V₅-V₆ (11/13) was presented in patients of DGCV2 group; R (without S or s) wave on V₁ (9/10), RS or Rs wave on V₅-V₆ were found in DGCV1 group; RS or rS wave was seen on lead V₁, R(without S)wave in lead V₅-V₆ (25/26) were found in EDGCV and PAIV group and the amplification of R wave in EDGCV was higher than V₁ of PAIV group.(3)Precordial lead transition zone was in front of V₁ for DGCV1 and DGCV2 groups (23/23), within V₁-V₃ for EDGCV group, but on V₂ or within V₂-V₃ for PAIV group.(4)Patients of DGCV1 and DGCV2 demonstrated a longer Pseudo delta wave time(PdW), intrinsicoid deflection time (IDT), significantly larger maximum deflection index (MDI) than those in PAIV and EDGCV groups (P<0.001). (5)The different characteristics of surface 12-lead ECG between VAs originating from DGCV and those from ventricular outflow tract and adjacent structure were as follows: ① The ECG features were similar between PVIA and LCC group, both demonstrated a rs wave on the lead Ⅰ, rS wave on V₁-V₂ and R wave on V₅-V₆; ②The ECG features were similar betweenEDGCV and RCC group, both presented with R or r wave on the lead Ⅰ, the QRS wave of precordial leads was similar as PAIV and LCC groups; ③A R wave on the lead V₁, V₅-V₆ was found in group DGCV2, and ILCC; ④Similar to the group Endo-MAA, patients in DGCV1 group also demonstrated a R wave on the lead V₁ and a Rs wave on V₅-V₆.

A positive R wave in inferior leads, a negative QS morphology in lead aVL and aVR are seen in all patients, but different electrocardiographic characteristics of PVC/VT originating from the different portions of the DGCV are presented on lead Ⅰ and V₁-V₆.

Ventricular premature complexes; Catheter ablation; Cardiac electrophysiology