Abstract 13451: Assessment of Diffuse Ventricular Fibrosis in Atrial Fibrillation Using Extracellular Volume Fraction: Initial Study

• Published in: Circulation (New York, N.Y.) N.Y.), 2015-11, Vol.132 (Suppl_3 Suppl 3), p.A13451-A13451
• Main Authors: Li, Song-Nan, Zhao, Lei, Wang, Lu, Lin, Hui, Wen, Song-Nan, Ning, Man, Ma, Xiao-Hai, Yu, Rong-Hui, Long, De-Yong, Tang, Ri-Bo, Sang, Cai-Hua, Jiang, Chen-Xi, Liu, Nian, Bai, Rong, Du, Xin, Dong, Jian-Zeng, Fan, Zhan-Ming, Ma, Chang-Sheng
• Format: Article
• Language: English
• ISSN: 0009-7322; 1524-4539
• DOI: 10.1161/circ.132.suppl_3.13451

ObjectivesIn atrial fibrillation (AF), diffuse myocardial fibrosis may be induced by arrhythmia or reflect pre-existing cardiomyopathy. The presence of concurrent AF and diffuse myocardial fibrosis has been associated with an increased risk of heart failure progression.Unlike focal fibrosis, diffuse myocardial fibrosis is not visualized on delayed enhancement magnetic resonance imaging (MRI), but can be quantified with ECV fraction.HypothesisThe extracellular volume (ECV) fraction may provide new insights to evaluate diffuse myocardial fibrosis of the left ventricle (LV) in patients with AF.Methods78 subjects underwent MRI using a clinical 3 T scanner (Magnetom Verio, Siemens Healthcare)25 persistent AF patients, 28 paroxysmal AF patients and 25 controls. Left-atrial volume was evaluated from MR cine imaging. A validated Look-Locker T1 Mapping Siemens prototype sequence was used to generate T1 maps as an index of diffuse myocardial fibrosis. The imaging parameters wereTE/TR = 1/295.33ms, FOV = 360mm, Slice Thickness = 8mm, image matrix = 192. 3 short axes of pre and post T1 maps were acquired as shown in Figure 1. ECV fraction was calculated from T1 maps acquired pre- and post-contrast calibrated by blood hematocrit. The ECV fraction was calculated as:ECV=(1-hematocrit)(1/(T1my post)-1/T1myopre)/(1/(T1blood post)-1/T1bloodpre)ResultsAF patients had larger left atrial volume (persistent AF175.7±65.9ml; paroxysmal AF116.7±43.6ml) than controls (76.6±12.8ml) (paroxysmal vs. controlP