Coronary Sinus (CS) Isolation
In patients with PersAF and LSPAF, some evidence suggests that the CS is a crucial trigger source for AF (87-90). The muscular sleeves of the CS can potentially serve as either an ectopic trigger or be part of a reentrant circuit for AF (91). Given its variable anatomy and, therefore, alternating trigger sites for AF, CS focal ablation is markedly challenging and time-consuming. Della Rocca et al. (92) found that complete CS isolation was associated with a significantly higher arrhythmia-free survival rate than focal CS ablation with a similar incidence of procedural complications. A recent randomized study revealed better outcomes with elimination of distal CS to LA connections compared to PVI and non-PV trigger ablation (93). Given the close relationship between the esophagus and the CS, continuous monitoring of the esophageal temperature is important to avoid complications (94). While ablating along the septal aspect, close monitoring of PR interval is pertinent. Prompt discontinuation of the ablation is recommended if signs of PR prolongation are detected to avoid injury to the atrioventricular (AV) nodal artery. (Figure 10)