Advanced atrial remodeling predicts poor clinical outcomes in human AF.
We aimed to define the magnitude and predictors of change in LA structural remodeling over 12 months of AF.
Thirty eight patients with paroxysmal AF managed medically (Group 1), 20 undergoing AF ablation (Group 2) and 25 control patients with no AF history (Group 3) prospectively underwent echocardiographic assessment of strain variables of LA reservoir function at baseline, 4, 8 and 12 months. In addition, P-wave duration (Pmax, , Pmean) and dispersion (Pdis) were measured. AF burden was quantified by implanted recorders. Twenty patients undergoing ablation underwent electroanatomic mapping (mean 333±40 points) for correlation with LA strain.
Group 1 demonstrated significant deterioration in total LA strain (26.3±1.2% to 21.7±1.2%, P<0.05), and increases in Pmax (132±3ms to 138±3ms, P<0.05) and Pdis (37±2ms to 42±2ms, P<0.05). An AF burden ≥10% was specifically associated with decline in strain and with P-wave prolongation. Conversely, Group 2 manifest improvement in total LA strain (21.3±1.7% to 28.6±1.7%, P<0.05) and reductions in Pmax (136±4ms to 119±4ms, P<0.05) and Pdis (47±3ms to 32±3ms, P<0.05). Change was not significant in Group 3. LA mean voltage (r=0.71, P=0.0005), percent low voltage electrograms (r=-0.59, P=0.006), percent complex electrograms (r=-0.68, P=0.0009) and LA activation time (r=-0.69, P=0.001) correlated with total strain as a measure of LA reservoir function.
High burden AF is associated with progressive LA structural remodeling. In contrast AF ablation results in significant reverse remodeling. These data may have implications for timing of ablative intervention.