Distal coronary sinus or left atrial appendage pacing unmasked concealed left pulmonary vein potentials in 64% of patients, separating them from LA potentials by a mean of 19 +/- 14 ms.
Observational (n=36)
Does distal CS or LA pacing unmask concealed left pulmonary vein potentials compared to sinus rhythm in patients with paroxysmal atrial fibrillation undergoing ablation?
Distal CS or LA pacing unmasks concealed left pulmonary vein potentials in approximately two-thirds of patients, facilitating successful radiofrequency ablation.
Pulmonary vein potentials (PVPs), though obvious during ectopic activity, are frequently invisible during sinus rhythm when they need to be distinguished from left atrial (LA) potentials to perform successful ablation procedures. Thirty-six patients with paroxysmal atrial fibrillation underwent circumferential PV mapping with a circular ten-electrode catheter during sinus rhythm, and during pacing from the right atrium, proximal and distal coronary sinus (CS), and LA. Ablation was performed at the ostium of the PV, the procedural endpoint consisting of electrical disconnection of the PV from the LA. A total of 93 PVs (excluding the right inferior PV) were mapped. During sinus rhythm, distinct right PVPs were present in all instances, while they were concealed within the electrograms recorded from the left inferior and superior PV in 23 (64%) patients. Distal CS or LA appendage pacing unmasked and separated left PV from LA potentials by a mean of 19 +/- 14 ms; the LA-to-left-PV potential interval measured 36 +/- 14 ms. The number of deflections also increased from 2.1 +/- 0.7 during sinus rhythm to 3 +/- 1.4 during LA stimulation. However, in the right superior PV, pacing caused overlapping of atrial potentials with right superior PVPs. RF ablation of the left PVPs was performed during distal or LA pacing in 23 patients, while in the right superior PV it was performed during sinus rhythm eliminating all, including unmasked, left PVPs, providing proof of their PV origin. Distal CS or LA pacing is required to recognize left PVPs in approximately 2/3 of patients and facilitates RF ablation.
Hocini et al. (2000) conducted an observational in Paroxysmal atrial fibrillation (n=36). Distal coronary sinus or left atrial appendage pacing vs. Sinus rhythm was evaluated on Unmasking and separation of left pulmonary vein potentials from left atrial potentials. Distal coronary sinus or left atrial appendage pacing unmasked concealed left pulmonary vein potentials in 64% of patients, separating them from LA potentials by a mean of 19 +/- 14 ms.