Differential effects of adenosine on pulmonary vein ectopy after pulmonary vein isolation: implications for arrhythmogenesis.
BACKGROUND
The mechanism of pulmonary vein (PV) triggers of atrial fibrillation remains unclear. We performed adenosine (ADO) testing after PV isolation to characterize spontaneous dissociated PV rhythm and ADO-induced PV ectopy.


RESULTS
Seventy-four patients (61 men; age, 61±10 years) undergoing PV isolation for atrial fibrillation were studied. For each isolated PV, dissociated ectopy was recorded and ADO was administered. After isolation of 270 PVs, 50 PVs with dissociated ectopy were identified. In 42 PVs exhibiting PV rhythm, ADO resulted in PV rhythm suppression in 35 (83%) PVs, with all occurring during ADO-induced bradycardia, and in PV rhythm acceleration in 13 (31%) PVs, with all occurring after resolution of ADO-induced bradycardia. In 11 PVs, both ADO-induced PV rhythm acceleration and suppression were seen. Among 220 electrically silent PVs, ADO induced PV ectopy in 28 (13%) veins. The timing of ADO-induced PV ectopy with respect to ADO effects on heart rate varied. ADO induced PV ectopy during the early phase of ADO effect only in 12 PVs, during the late phase of ADO effect only in 8 PVs, and during both early and late phases of ADO effect in 8 PVs.


CONCLUSIONS
The mechanism of spontaneous PV rhythm after isolation is likely automaticity, given the close association of ADO effects on PV rhythm with its chronotropic and dromotropic effects. However, ADO can induce PV ectopy in electrically silent PVs in a manner not closely tied to its effects on heart rate and may be because of the activation of autonomic triggers.
Department of Medicine, Division of Cardiology, Weill Cornell Medical College, New York, NY 10021, USA. jac9029@med.cornell.edu
Jim W
JW
Cheung
James E
JE
Ip
Jeffrey H
JH
Chung
Steven M
SM
Markowitz
Christopher F
CF
Liu
George
G
Thomas
Joseph M
JM
Lee
Seth J
SJ
Lessner
Bruce B
BB
Lerman
D000241:Adenosine / Q000008:administration & dosage; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D017115:Catheter Ablation; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D009519:New York City; D011237:Predictive Value of Tests; D011667:Pulmonary Veins / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D000241:Adenosine