Pulmonary vein contraction before and after radiofrequency ablation for atrial fibrillation.
BACKGROUND
Cardiovascular magnetic resonance imaging (cMRI) may provide a noninvasive method to test for pulmonary vein (PV) isolation after ablation for atrial fibrillation (AF) by detecting changes in PV contraction.


METHODS
PV contraction (the maximal percentage change in PV cross-sectional area [CSA] during the cardiac cycle) measured 1 month before and 2 months after PV isolation was compared in 63 PVs from 16 patients with medically refractory AF. Repeat cMRI imaging and invasive catheter mapping was performed prior to repeat PV ablation in 50 PVs from 14 additional patients with recurrent AF. Contraction in PVs with sustained isolation after the initial ablation was compared to contraction in PVs with electrical reconnection to adjacent atrium. Receiver operating characteristic (ROC) curve analysis was performed to determine the optimal cutoff PV contraction value for prediction of PV-atrial reconnection after ablation. The cutoff value was then prospectively tested in 40 PVs from 12 additional patients.


RESULTS
PV contraction decreased after AF ablation (22.4 ± 10% variation in CSA before ablation vs 10.1 ± 8% variation in CSA after ablation, P < 0.00001). PVs with sustained isolation on invasive mapping contracted less than PVs with electrical reconnection to adjacent atrium (13.7 ± 10.6% vs 21.4 ± 9.3%, P = 0.021). PV contraction produced a c-index of 0.74 for prediction of PV-atrial reconnection after ablation and >17% variation in PV CSA predicted reconnection with a sensitivity of 84.6% and specificity of 66.7%.


CONCLUSIONS
PV contraction is reduced by ablation. PV contraction measurement may provide a noninvasive method to test for PV isolation after ablation procedures.
Atwater
Brett D
BD
Division of Cardiovascular Medicine, Department of Internal Medicine, Duke University Medical Center, Durham, North Carolina, USA. brett.atwater@duke.edu
Wallace
Thomas W
TW
Kim
Han W
HW
Hranitzky
Patrick M
PM
Bahnson
Tristram D
TD
Hegland
Donald D
DD
Daubert
James P
JP
D000368:Aged; D001281:Atrial Fibrillation / Q000503:physiopathology* / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000503:physiopathology*; D011667:Pulmonary Veins / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome; D014661:Vasoconstriction