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)