Delayed Success Following Radiofrequency Catheter Ablation of Ventricular Premature Contractions Originating from Right Ventricular Mid Septum

Abstract

There were few reports about delayed success following radiofrequency catheter ablation of ventricular premature contractions (VPCs). A 72-year-old female was admitted to our hospital to treat frequent VPCs. The electrocardiogram (ECG) showed sinus rhythm at 75 bpm and VPCs with the inferior axis and left bundle branch block. QRS morphology of VPCs was Q wave in V1 and RSR pattern in aVL. We expected that the origin of VPCs was right ventricular (RV) mid septum. In holter ECG recording, the number of VPCs was 25000 beats/day. Catheter ablation was performed to eliminate VPCs. Ablation catheter was positioned at RV mid septum with ventricular electrogram preceded 22 ms from the onset of QRS of VPCs. VPCs were disappeared during radio frequency current delivery, but VPCs were recurred just after RF application. However total RF time was 26 minutes, VPCs were not eliminated finally. For eight hours just after ablation, VPCs were occurred 30 beats/min and increased in comparison with preablation period. After eight hours from ablation, VPCs decreased gradually, and 48 hour later VPC was disappeared. Conclusion: These observations demonstrate that continued evolution of RF lesions may result in the eventual success of an initially unsuccessful ablation session.