Abstract 19078: Pre-Existing Left Atrial Fibrosis and Diastolic Dysfunction is Associated With Deterioration in Diastolic Function Following Left Atrial Ablation In Patients With Recurrent Atrial Fibrillation
Background: Radiofrequency (RF) ablation for treatment of atrial fibrillation (AF) is known to induce left atrial (LA) fibrosis. LA diastolic dysfunction has been associated with AF and has shown predictive value for AF recurrence post ablation. This study is designed to evaluate the pattern of change in LA diastolic function following RF ablation.
Methods: A total of 127 consecutive AF patients were enrolled in the AF Ablation MRI cohort. Fourteen underwent a repeat ablation for recurrent AF and were selected. During routine ablation procedure, LA pressures were acquired in sinus rhythm following trans-septal puncture and prior to ablation. LA diastolic function was evaluated by measuring the slope of the passive LA filling curve and was quantified using diastolic function scores defined by the ratio of change of LA pressure (as defined by invasive pressure measurements) to volume (as defined by MRI) during passive filling of LA (ΔP/ΔV) mmHg/ml and was measured prior to both ablations. The change in LA diastolic function was considered significant if >25% change from baseline was observed. Percent left atrial fibrosis was quantified by using the image intensity ratio as previously described.
Results: The mean diastolic function score for the 14 AF patients (62±7yrs, 79% male) was 0.76±0.28 mmHg/ml (Paroxysmal AF 0.58±0.18 and persistent AF 0.90±0.28, p=0.031). Of these, 4 (28.6%) patients had no substantial change >25% in their diastolic function score (grp A) at repeat imaging. Six had improvement, 4 remained stable, grp B and 4 had deterioration-grp C. When compared with group A, group C had worse baseline LA diastolic function (0.6±0.2 v 1.1±0.3, p0.019) and greater baseline fibrosis (8.0±2.4% v 15.3±7.0, p0.042).
Conclusion: Deterioration of diastolic function in patients with AF recurrence after LA ablation is associated with more extensive baseline fibrosis and worse baseline LA diastolic function.
- © 2013 by American Heart Association, Inc.