Endocardial, epicardial, and right atrial approach for catheter ablation of premature ventricular contractions from the inferoseptal process of the left ventricle

Background Inferoseptal process of the left ventricle (ISP-LV) might be a source idiopathic ventricular arrhythmias. In these cases, ectopic foci are accessible from LV endocardium, epicardially middle cardiac vein as well right atrium (RA). This study reports series patients with premature contractions (PVCs) arising ISP-LV that were successfully ablated following access different structures. Methods and Results Five (4 males, age 61 ± 12.8 years) PVCs using three approaches for ablation—endocardial, epicardial (through coronary sinus or its branches), RA approaches. Endocardial mapping, RA, (CS) mapping performed in all five cases. demonstrated RBBB LBBB-like morphology superior axis. The endocardially had maximum deflection index (MDI) 0.36, 0.43, 0.54, whereas remaining 2 patients, MDI was 0.57 both QS inferior leads. Local activation time at successful ablation site 35 8.9 (26–55) msec pre-QRS. Pacemapping resulted good (11/12) perfect (12/12) QRS match Three frequent monomorphic another suggesting remote exit site. All remained arrhythmia-free after mean follow-up 21 15 (6–36) months. Conclusion Successful may require CS even apart endocardial approach. Not infrequently demonstrate additional PVC foci.