Electroanatomic mapping of transseptal conduction during coronary sinus pacing in patients with paroxysmal atrial fibrillation.

OBJECTIVE

To delineate the electrophysiological properties of transseptal conduction from the left to the right atrium in patients with paroxysmal atrial fibrillation (AF).

DESIGN AND

RESULTS

Right atrial mapping using the electroanatomic mapping technique was performed at 111 +/- 16 sites in 16 patients with paroxysmal AF during pacing from distal coronary sinus (CS). A single transseptal breakthrough near the CS ostium was observed in all patients. The activation time from the pacing site to the earliest septal activation site was 47 +/- 13 ms. The total septal activation time (68 +/- 16 ms) was markedly longer but the total right atrial activation time (118 +/- 17 ms) was similar to that in patients without AF in a previous observation.

CONCLUSION

During distal CS pacing, a preferential site of transseptal conduction near the CS ostium was demonstrated in patients with paroxysmal AF. This has clinical implications when surgical dissection or catheter ablation is considered to eliminate interatrial connection in patients with AF.