Atrial fibrillation (AF) is common in the setting of abnormal ventricular relaxation.

We evaluated the association between ventricular relaxation grade and atrial fibrosis and examined the change in left ventricular filling parameters following catheter ablation.

AF patients undergoing catheter ablation who had cardiac late gadolinium enhancement MRI (LGE-MRI) and echocardiographic examinations were included in the study. Left atrial (LA) tissue fibrosis and volume were quantified using LGE-MRI. Echocardiograms were performed at baseline and 3 months following catheter ablation to assess left ventricular (LV) filling. Two hundred and ninety three patients (60.8 % male) met the inclusion criteria. In patients in sinus rhythm at baseline (n = 115), ventricular relaxation pattern was identified as normal in 54 patients (47.0 %), impaired in 35 (30.4 %), pseudo-normal in 18 (15.7 %), and restrictive in 8 (7.0 %). Restrictive LV filling was associated with higher LA volume index (61.2 ± 30.5 vs 46.0 ± 18.5 ml/m²; p < 0.01) and LA fibrosis (21.8 ± 10.9 % vs 15.5 ± 9.4 %; p = 0.036) compared to non-restrictive filling. In patients in sinus rhythm on both pre- and post-ablation echocardiograms (n = 104), A waves decreased from 0.70 ± 0.23 at baseline to 0.60 ± 0.20 (p < 0.01) and E/E’ decreased from 9.6 ± 4.0 at baseline to 8.6 ± 3.5 (p = 0.03). Thirty-two patients (27.2 %) had an improvement, and 24 patients (23.1 %) had a worsening in diastolic grade. Clinical heart failure and diabetes were associated with worse diastolic grade post-ablation.

Restrictive LV filling is associated with higher LA fibrosis. A change in echocardiographic LV filling pattern was noted in over 50 % of patients post-ablation.