Purpose: Posteroseptal accessory pathways may be associated with a coronary sinus (CS) diverticulum. Our purpose was to describe the clinical characteristics, mapping and ablation of these pathways.
Methods: This was a retrospective study of all patients who underwent ablation of posteroseptal accessory pathways in a single centre. Patients with a diverticulum of the CS or one of its tributaries were included in group I, while the other patients formed group II. Clinical presentation, ablation procedure and outcome were compared between the two groups.
Results: A total of 51 patients were included, 16 in group I and 35 in group II. There were no significant differences in age or sex distribution. Atrial fibrillation (AF) and previous unsuccessful ablation were more common in group I. A negative delta wave in lead II was the ECG finding with best sensitivity and specificity for the presence of a diverticulum. A pathway potential was common at the successful site in group I, and the interval between local ventricular electrogram and delta wave onset was shorter (19.5 ± 8 vs 33.1 ± 7.6 ms, p < 0.001). There was a trend toward lower procedural success rate and higher recurrence rate in group I, although this was not significant.
Conclusions: CS diverticula should be suspected in patients with manifest posteroseptal accessory pathways who have a previous failed ablation, documented AF or typical electrocardiographic signs. A discrete potential is frequently seen at the successful site, but the local ventricular electrogram is not as early as in other accessory pathways.
Keywords: Ablation; Coronary sinus; Diverticulum; Posteroseptal; WPW.