Coronary sinus(CS) electrode catheter has been used ad a very useful mapping and guiding tool in catheter ablation of the left-side atrioventricular pathway(AP). Recently, it was reporter that single catheter approach of catheter ablation of the manifest left-side AP was feaside with a comparable success rate but shorter fluoroscopy time, compared with the standard approach. This study was performed to evaluate the role of CS electrode catheter in catheter avlation of the lefr-side AP.

Sixty-five consecutive patients(43 men, 22 women) with a single left-side AP were included in this study. The first 32 patients underwent catheter ablation with an eletrode catheter in CS(CS+ group: 19 men, 13 women: 42.3± 14.6 years) and the later 33 patients with no electrode catheter in CS(CS- group: 24 men, 9 women: 38.8± 14.1 years). APs were localized by mapping the CS in CS+ group or by mapping the mitral valve annulus in CS- group with a 4mm-tipped deflectable catheter(7F, Webster or EPT). Radiofrequency energy(RF) was delivered unipolarly at a fixed power of 30-50 volts or 30-60 seconds. AP location, succes rate, number of RF applications, fluoroscopy time, and complications were compared between 2 group.

APs were located at the left posteroseptal wall in 2(6.2%), left posterior wall in 5(15.5%), left posterolateral wall in 3(9.3%), left lateral wall in 18(56.3%), left anterolateral wall in 4(12.5%) in CS+ group. In CS- group, there were 6(18.2%) left posteroseptal, 2(6.1%) left posterior, 5(15.2%) left posterolateral, 12(36.4%) left lateral, 8(24.2%) left anterolateral AP with no significant difference in the distribution of the APs between 2 groups. The proportions of concealed and manifest APs wrer similar in 2 groups(17/15 vs. 19/14). Twenty-eight(87.5%) of 32 APs in CS+ group and 30(90.9%) of 33 APs in CS- group were successfully ablated showing no signigicant difference in the succes rates between 2 groups. The numbers of RF applications to ablate the APs were similar between 2 groups(3.9±3.4 vs. 3.5±2.9). Total fluoroscopy times wrer also similar between 2 groups(54.3±33.5 minutes vs. 47.2±21.4 minutes). There were no major conplications in both groups.

Radiofrequency catheter ablation of the left-side APs may be successfully performed without using a CS electrode catheter as a guide in diagmosing and localizing left-side APs.