Pablo B Nery1, Wafa Al Dawood2, Girish M Nair2, Calum J Redpath2, Mouhannad M Sadek2, Li Chen3, Martin S Green2, George Wells3, David H Birnie2. 1. Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. Electronic address: PNery@ottawaheart.ca. 2. Division of Cardiology, Department of Medicine, University of Ottawa Heart Institute, Ottawa, Ontario, Canada. 3. Cardiovascular Research Methods Center, University of Ottawa Heart Institute, Ottawa, Ontario, Canada.
Abstract
BACKGROUND: There is limited data on the scar burden in patients with atrial fibrillation (AF). In this study, we sought to evaluate the presence and extent of an abnormal left atrial (LA) substrate in patients with paroxysmal or persistent AF. METHODS: Consecutive patients who underwent initial AF catheter ablation were prospectively enrolled. Endocardial voltage mapping was acquired in sinus rhythm using multipolar mapping catheters. Automated software was used to ensure homogeneous data collection. Assessment of low-voltage area (LVA) was performed by a reviewer blinded to clinical details. RESULTS: One hundred and four patients were prospectively enrolled; 69 had paroxysmal and 35 persistent AF. The mean LA volume was 159 ± 48 mL, and the average number of LA points collected was 1308 ± 1065. Atrial LVAs were present in 23 of 69 (33%) subjects with paroxysmal and 20 of 35 (57%) with persistent AF (P = 0.02). Amongst 43 of 104 patients with scar, the average extent of LVA was 19.4 ± 21.6 cm2 and the mean percentage area was 7.6 ± 8.8%. Univariate analysis showed that age, LA volume, and persistent AF were associated with the presence of LVA. Multivariable analysis showed that age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.00-1.11; P = 0.046) and LA volume (OR 1.02; 95% CI 1.01-1.04; P < 0.001) remained predictors of LVA. AF classification (persistent vs paroxysmal) was not a predictor of an abnormal atrial substrate (OR 1.34; 95% CI 0.4-3.9; P = 0.56). CONCLUSIONS: There is wide variability in the presence and extent of LVA in patients with paroxysmal or persistent AF. Age and LA volume were predictors of LVA. There was no correlation between AF classification and the presence of LVA.
BACKGROUND: There is limited data on the scar burden in patients with atrial fibrillation (AF). In this study, we sought to evaluate the presence and extent of an abnormal left atrial (LA) substrate in patients with paroxysmal or persistent AF. METHODS: Consecutive patients who underwent initial AF catheter ablation were prospectively enrolled. Endocardial voltage mapping was acquired in sinus rhythm using multipolar mapping catheters. Automated software was used to ensure homogeneous data collection. Assessment of low-voltage area (LVA) was performed by a reviewer blinded to clinical details. RESULTS: One hundred and four patients were prospectively enrolled; 69 had paroxysmal and 35 persistent AF. The mean LA volume was 159 ± 48 mL, and the average number of LA points collected was 1308 ± 1065. Atrial LVAs were present in 23 of 69 (33%) subjects with paroxysmal and 20 of 35 (57%) with persistent AF (P = 0.02). Amongst 43 of 104 patients with scar, the average extent of LVA was 19.4 ± 21.6 cm2 and the mean percentage area was 7.6 ± 8.8%. Univariate analysis showed that age, LA volume, and persistent AF were associated with the presence of LVA. Multivariable analysis showed that age (odds ratio [OR] 1.05; 95% confidence interval [CI] 1.00-1.11; P = 0.046) and LA volume (OR 1.02; 95% CI 1.01-1.04; P < 0.001) remained predictors of LVA. AF classification (persistent vs paroxysmal) was not a predictor of an abnormal atrial substrate (OR 1.34; 95% CI 0.4-3.9; P = 0.56). CONCLUSIONS: There is wide variability in the presence and extent of LVA in patients with paroxysmal or persistent AF. Age and LA volume were predictors of LVA. There was no correlation between AF classification and the presence of LVA.