Dilated LA significantly increases the risk of AF recurrence after  single CPVI .
This is especially applicable to the patients with long-term follow-up
AIMS Left atrial ( LA ) enlargement is associated with atrial fibrillation ( AF ) .
However , it is controversial whether dilated atrium can predict post-ablation AF recurrence .
We undertook a systematic review and meta- analysis to analyse the association between LA diameter and  AF recurrence after single circumferential pulmonary vein isolation ( CPVI )  and explore the potential mechanism .
Detection and Quantification of Left Atrial Structural Remodeling With Delayed-Enhancement Magnetic Resonance Imaging in Patients With Atrial Fibrillation
Background — Atrial fibrillation ( AF ) is associated with diffuse left atrial fibrosis and a reduction in endocardial voltage . These changes are indicators of AF severity and appear to be predictors of treatment outcome . In this study , we report the utility of delayed-enhancement magnetic resonance imaging ( DE-MRI ) in detecting abnormal atrial tissue before radiofrequency ablation and in predicting procedural outcome . Methods and Results — Eighty-one patients presenting for pulmonary vein antrum isolation for treatment of AF underwent  3-dimensional DE-MRI of the left atrium before the ablation .  Six healthy volunteers also were scanned . DE-MRI images were manually segmented to isolate the left atrium , and custom software was implemented to quantify the spatial extent of delayed enhancement , which was then compared with the regions of low voltage from electroanatomic maps from the pulmonary vein antrum isolation procedure . Patients were assessed for AF recurrence at least 6 months after pulmonary vein antrum isolation , with an average follow-up of 9.6±3.7 months ( range , 6 to 19 months ) . On the basis of the extent of preablation enhancement , 43 patients were classified as having minimal enhancement ( average enhancement , 8.0±4.2 % ) , 30 as having moderate enhancement ( 21.3±5.8 % ) , and 8 as having extensive enhancement ( 50.1±15.4 % ) . The rate of AF recurrence was 6 patients ( 14.0 % ) with minimal enhancement , 13 ( 43.3 % ) with moderate enhancement , and 6 ( 75 % ) with extensive enhancement ( P<0.001 ) . Conclusions — DE-MRI provides a noninvasive means of assessing left atrial myocardial tissue in patients suffering from AF and might provide insight into the progress of the disease . Preablation DE-MRI holds promise for predicting responders to AF ablation and may provide a metric of overall disease progression
Dilated LA significantly increases the risk of AF recurrence after  single CPVI .
This is especially applicable to the patients with long-term follow-up
AIMS Left atrial ( LA ) enlargement is associated with atrial fibrillation ( AF ) .
However , it is controversial whether dilated atrium can predict post-ablation AF recurrence .
We undertook a systematic review and meta- analysis to analyse the association between LA diameter and  AF recurrence after single circumferential pulmonary vein isolation ( CPVI )  and explore the potential mechanism .