Role of Rapid Focal Activation in the Maintenance of Atrial Fibrillation Originating from the Pulmonary Veins

Abstract

KUMAGAI, K., ET AL.: Role of Rapid Focal Activation in the Maintenance of Atrial Fibrillation Origi nating from the Pulmonary Veins. Most episodes of focal atrial fibrillation (AF) can be initiated by pre mature beats originating from the pulmonary veins (PV). However, the role of rapid focal activation in the maintenance of AF is unclear. Thirty-two patients with focal AF who underwent focal ablation of trigger ing ectopic beats were studied. Bipolar electrograms from all four PVs were recorded simultaneously.The cycle length (CL) of RFA at sites that triggered AF was measured at AF onset, after 5 minutes of sustained AF, and just before the spontaneous termination of 32 episodes of nonsustained AF. Fifteen episodes of sustained AF (> 10 minutes) and 17 episodes of nonsustained AF (5-120 seconds, mean 56 ± 59 seconds) were analyzed. In sustained AF, the mean CL of RFA in the PV from which it originated was not signifi cantly different than in the other PVs, and RFA was continuously observed. In nonsustained AF, the mean CL of RFA in a PVfrom which it originated was significantly shorter than in other PVs and, when RFA dis appeared, AF terminated. RFA in 1 PV induced RFA in another PV. In conclusion, widespread conduc tion of RFA from a PV at its source to the other sites may be necessary for the sustenance of AF. A PV in teraction, a RFA triggering another, may be involved in the maintenance of AF. RFA arising from PVs is important not only as a trigger of onset, but also in the maintenance of

Role of the Posterior Left Atrium and Pulmonary Veins in Human Lone Atrial Fibrillation

“…7,20 Increasingly, evidence suggests that the same events may maintain AF by continuing to trigger the arrhythmia. 5,9,21 Given the relative similarity between the patients in this series and those undergoing AF ablation, it is likely that focal firing played a role.…”

“…A primary electrophysiological (EP) action with focal initiators/drivers of AF from the pulmonary veins [7][8][9] and/or spiral waves 10 in the posterior LA has been suggested. LA pathology favoring reentry may be important for maintenance of AF.…”

Catheter Ablation for Atrial Fibrillation

“…4) AF is also perpetuated by microreentrant circuits, or rotors, that exhibit high-frequency, periodic activity from which spiral wave fronts of activation radiate into surrounding atrial tissue. 5,6) Conduction becomes slower and less organized with increasing distance from the rotors, likely because of atrial structural remodeling, resulting in fibrillatory conduction.…”

Treatment of Paroxysmal Atrial Fibrillation by Pulmonary Vein Isolation

“…[9][10][11][12][13] Pulmonary vein tachycardia usually occurs in short bursts, and can be recognized during an episode of AF by the presence of a shorter atrial cycle length within a pulmonary vein than in the adjacent left atrium (Fig 1). 11 Several lines of evidence indicate that these bursts of rapid electrical activity arise within the pulmonary veins, as opposed to representing fractionation of the wave fronts that enter the pulmonary veins from the left atrium.…”