Response of pulmonary vein potentials to burst pacing.
BACKGROUND
Pulmonary vein potentials recorded at the ostia of pulmonary veins (PV) are a useful guide for segmental isolation of the PV in patients with atrial fibrillation (AF). Even during coronary sinus pacing at 600 ms, atrial (A) and PV potentials can overlap in 50-60% of patients making the accurate identification of PV potentials very difficult.


METHODS
Nineteen patients (M:F 15:4) with paroxysmal AF underwent segmental isolation of one or more PV. Coronary sinus (CS) pacing was performed at cycle lengths of 600/550/500/450/400/350/300 ms and bipolar electrograms were recorded from the 10 or 20 pole Lasso catheter placed at the atrial-PV junction in 27 pulmonary veins. Stimulus (S) to A, S-PVP and A-PVP intervals were measured during CS pacing at the different cycle lengths at sweep speed of 200 mm/sec.


RESULTS
During CS pacing at 600 ms the A and PV potentials were significantly overlapped (A-PVP < or = 25 ms) in 15 of 27 (55%) veins. During pacing at 300 ms, the A and PV potentials were significantly separated (A-PVP > or = 25 ms) in 9 of the 15 veins where A and PV potentials overlapped and 21 of all 27 (78%) veins. In two patients pacing at 300 ms was associated with 2:1 conduction block from atrial to PV fascicle.


CONCLUSIONS
Coronary sinus pacing at cycle length of 300 ms demonstrated better separation of A and PV potentials compared to pacing at 600 ms. This strategy is easier and less time consuming compared to extrastimuli testing. It also confirms that the electrophysiological properties of PV fascicles are different from that of the adjacent atrial musculature.
Vijayaraman
Pugazhendhi
P
Cardiac Electrophysiology, Division of Cardiology, McGuire VA Medical Center, Richmond, Virginia 23249, USA. p.vijayaraman@med.va.gov
Kok
Lai Chow
LC
Shepard
Richard K
RK
Wood
Mark A
MA
Ellenbogen
Kenneth A
KA
D001281:Atrial Fibrillation / Q000175:diagnosis / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D017115:Catheter Ablation; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011667:Pulmonary Veins / Q000503:physiopathology*