Importance of great cardiac vein signal in the differentiation of premature ventricular contraction origins in right and left ventricular outflow tracts

Background and Aim: "Idiopathic" ventricular arrhythmias most often arise from the right ventricular outflow tract (RVOT), although arrhythmias from the left ventricular outflow tract (LVOT) have also been observed. The aim of the study was to investigate the importance of signal of great cardiac vein (GCV) to distinguish premature ventricular contraction (PVC) originated from LVOT and PVC originated from RVOT. Materials and Methods: A coronary sinus catheter was placed in the GCV under fluoroscopy to measure the distance of GCV signal to the onset of QRS on surface electrocardiogram (ECG). Catheter ablation was performed utilizing radiofrequency energy in 31 patients. A 12-lead ECG was recorded during PVC. Successful ablation was defined as the complete disappearance of target PVC with no recurrence during the follow-up. Results: Thirty-one consecutive patients (16 male [51.6%]) were enrolled. Overall, 67.7% of the cases had PVC originated from the LVOT and 32.3% from the RVOT. Out of 48.4% of the females, 33.3% had PVC originated from the RVOT and 66.7% from the LVOT (P = 1). The mean ejection fraction regarding PVC originated from the LVOT and RVOT was 47.50 +/- 8.95 and 45.50 +/- 8.51, respectively (P = 0.7). The distance of GCV signal to the onset of QRS on surface ECG for LVOT- and RVOT-originated PVC was 15.38 +/- 25.28 and -29.70 +/- 25.66, respectively (P < 0.01). Conclusions: The differentiation between PVC originated from LVOT and RVOT is not entirely utilized through ECG criteria, thus the origin of PVC arising from RVOT/LVOT can be localized using the GCV signals.