1008-14 Radiofrequency Catheter Ablation of Left-sided Accessory Pathways: Selection of Coronary Sinus as the Primary Approach

Abstract

Listen

Translate article

We employed the coronary sinus (CS) for radiofrequency catheter ablation either as a primary technique or as a secondary approach after failed endocardial attempts in 12 pts (mean age 40 ± 20 yrs) with 14 accessory pathways (AP): 9 left paraseptal, 4 left posterolateral, 1 left anterolateral. AP to local atrial (AP/A) and ventricular (AP/V) electrogram amplitude ratios were calculated. CS angiograms were obtained in 9 pts. Results: AP potentials were recorded from the CS in all pts. All APs were successfully ablated using either CS ablation alone or combined with LV endocardial ablation. Catheter ablation within the CS eliminated conduction in 10 of 14 (71.4%) APs (Group 1) with the median of 7 (range 3 to 14) radiofrequency pulses and mean duration of 18 ± 5s at mean power of 22 ± 3W; 5 of these 10 APs were ablated from the CS as a primary method, and the other 5 APs were ablated from the CS after the failure of prior endocardial ablation. In remaining 4 APs (Group 2) the primary CS ablation failed and pathways were ablated with a subsequent endocardial approach. In Groups 1&2, AP/A ratio was 1 ± 0.5 & 0.55 ± 0.1 (p < 0.05), and AP/V ratio was 1.2 ± 0.6 &0.4 ± 0.3 (p < 0.05), respectively. In Group 1,9/10 successful ablations had an AP/A andlor AP/V ratios ≥ 1, whereas in Group 2 none of the CS recordings had an electrogram ratio ≥ 1. In all 5 Group 1 pts failing endocardial ablation, an AP potential was not recorded at the, endocardial site. 5 of 7 successfully ablated left paraseptal APs were adjoining the middle cardiac vein or a CS anomaly. CS perforation or thrombosis was not observed. During followup of 10 ± 7 mos there was no recurrence of sustained supraventricular tachycardia in any pt. (1) The CS can be used for both mapping as well as safe and effective ablation of left-sided APs with radiofrequency power outputs upto 30 W. (2) It can be utilized as a primary ablation approach for APs with AP/A or AP/V ratios ≥ 1. (3) These findings are most commonly seen in left paraseptal APs in proximity to the middle cardiac vein or a venous anomaly. (4) Endocardial ablation can be reserved for left-sided APs with electrogram ratios < 1.