Cor Vasa 2012, 54(11-12):e386-e392 | DOI: 10.1016/j.crvasa.2012.11.004

Poor relationship between left atrial diameter and volume in patients with atrial fibrillation

Štěpán Havránek^a,*, Veronika Bulková^a,b, Martin Fiala^b, Libor Škňouřil^b, Jan Chovančík^b, Jan Šimek^a, Dan Wichterle^a,d

^a II. interní klinika kardiologie a angiologie, 1. lékařská fakulta Univerzity Karlovy a Všeobecná fakultní nemocnice, Praha, Česká republika

^b Oddělení kardiologie, Kardiocentrum, Nemocnice Podlesí, a. s., Třinec, Česká republika

^c Interní kardiologická klinika, Lékařská fakulta Masarykovy univerzity a Fakultní nemocnice Brno, Brno, Česká republika

^d Klinika kardiologie, Institut klinické a experimentální medicíny, Praha, Česká republika

Background: Left atrial (LA) enlargement is a predictor of worse outcome after catheter ablation for atrial fibrillation (AF). We investigated the correspondence between single LA diameter (LAd) and LA volume (LAV) in patients undergoing catheter ablation for AF.

Methods: Total 782 patients (aged 58 ± 11 yrs; 70% males; 56% paroxysmal AF) were enrolled in 2 centres in the period of 2007-2011. Echocardiographic antero-posterior LAd was assessed in parasternal long-axis view and LAV was derived from electroanatomical 3D reconstruction of LA (183 ± 50 CARTO mapping points; 55% CT image registration).

Results: Mean LAd was 45 ± 6 mm (median: 45; IQR: 41-49; range: 25-73 mm) and mean LAV was 134 ± 42 ml (median: 128; IQR: 103-160; range: 46-313 ml). Correlation between both variables was weak (r = 0.56; p < 0.0001) and area under the ROC curve for the LAd-based prediction of LAV > 130 ml was 0.76. Accordingly, severe dilation of LA (LAV > 160 ml; upper quartile) was found only in 56% of patients with LAd > 50 mm while it appeared in 11% of those with LAd < 45 mm. In multivariate regression analysis, age, gender, and type of AF were independent covariates of LAV yielding the equation of LAV (ml) = 68 + 0.413. LAd (cc) + 15 (if male) + 0.48.age (yrs) - 21 (if paroxysmal AF). Substantial between-centre bias was also found reflecting subjective nature of echocardiographic readings. Adjustment for all covariates improved the correspondence between LAd-predicted and true LAV only modestly (AUC increased from 0.76 to 0.83) with wide 95% limits of agreement (-58 to +60 ml).

Conclusions: Considerable disagreement between echocardiographic LAd and 3D mapping LAV was observed in patients with non-valvular atrial fibrillation. Single LA dimension should not be considered relevant criterion for the indication of rhythm/rate control therapy and, particularly, for the selection of suitable candidates for catheter ablation.

Keywords: Atrial fibrillation; Catheter ablation; Echocardiography; Electroanatomical mapping; Left atrial size

Received: October 31, 2012; Accepted: November 9, 2012; Published: November 1, 2012  Show citation