Radiofrequency ablation of persistent left superior vena cava with left double accessory pathways: a case report and systematic review.

PURPOSE: Ablation of the persistent left superior vena cava (PLSVC) with a left accessory pathway is more difficult than ablation in the case of an ordinary left accessory pathway. We report a case of successful ablation of the PLSVC with a left double accessory pathway. We also conducted a systematic review of the literature to summarize the procedural precautions and technical points for patients with PLSVC with a left accessory pathway. OBSERVATION: A 48-year-old man was admitted with recurrent episodes of tachycardia. Electrocardiography revealed preexcitation. Preoperative echocardiography revealed PLSVC. Under the guidance of CARTO system mapping, an ablation catheter was used for mapping under sinus rhythm. The earliest V wave was mapped on the left lateral wall, AV fusion was achieved, the catheter was discharged with temperature control for 30 W, the AV was separated, and the delta wave disappeared. During the observation process, another type of delta wave was observed. The earliest V wave was detected in the anterior wall, the AV was fused, and then, the catheter was discharged at 30 W with temperature control. The AV separated, and the delta wave disappeared. Repeated electrophysiological examination could not induce tachycardia. The delta wave did not recover, and tachycardia did not recur after 5 months of follow-up. This systematic review revealed that approximately 4.23% of patients with PLSVC combined with left accessory pathways also have multiple accessory pathways. In cases of aortic retrograde ablation failure, successful ablation was achieved through the atrial septal puncture approach or via the coronary sinus. CONCLUSION AND IMPORTANCE: This case highlights the complexity of PLSVC combined with a left accessory pathway. Careful observation, accurate mapping and repeated verification are needed to improve the success rate of ablation.