Electrophysiological characteristics and radiofrequency catheter ablation of paroxysmal supraventricular tachycardia associated with persistent left superior vena cava

Objective To investigate the electrophysiological characteristics of paroxysmal supraventricular tachycardia(PSVT)associated with persistent left superior vena cava(PLSVC)and the safety and efficacy of their radiofrequency catheter ablation(RFCA). Methods Twelve consecutive patients with PLSVC out of 883 cases with PSVT who underwent RFCA at our hospital between July 2014 and Jan 2017 were included.Electrophysiological tests were performed and characteristics of radiofrequency ablation were analyzed. Results In 12 patients with PLSVC, 88.9 percent were women(9 cases), with an average age of 35.1±11.8(23-57)years.Of those 9 patients were identified to be atrioventricular nodal reentrant tachycardia(AVNRT)by electrophysiological examination and ablation was successfully completed at the routine target site in only 2 patients, while the other 7 required ablation at the anterior wall of the coronary sinus ostium, where effective target potential was a relatively fractionated and complex atrial electrogram followed by a large ventricular electrogram(A/V ratio>1∶3). A type Wolff-Parkinson-White syndrome(A-WPW)was confirmed in the other 3 patients.Transseptal approach was used successfully for ablation in 3 patients with A-WPW. Conclusions RFCA of PSVT associated with PLSVC is feasible and safe.For AVNRTs, the majority of target sites were located in the anterior wall of the coronary sinus ostium.The ablation strategy of A-WPW associated with PLSVC was not different from conventional method. Key words: Tachycardia, supraventricular; Catheter ablation; Persistent left superior vena cava; Coronary sinus