Rajiv Mahajan1, Adam Nelson2, Rajeev K Pathak2, Melissa E Middeldorp2, Christopher X Wong2, Darragh J Twomey2, Angelo Carbone2, Karen Teo2, Thomas Agbaedeng2, Dominik Linz2, Joris R de Groot3, Jonathan M Kalman4, Dennis H Lau2, Prashanthan Sanders5. 1. Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia; Department of Cardiology, Lyell McEwin Hospital, Adelaide, Australia. 2. Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia. 3. Heart Center, Department of Cardiology, Academic Medical Center, Amsterdam, the Netherlands. 4. Department of Cardiology, Royal Melbourne Hospital, Melbourne, Australia; Department of Medicine, University of Melbourne, Melbourne, Australia. 5. Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia. Electronic address: prash.sanders@adelaide.edu.au.
Abstract
OBJECTIVES: The aims of the study were to characterize: 1) electrical and electroanatomical remodeling in patients with atrial fibrillation (AF) with obesity; and 2) the impact of epicardial fat depots on adjacent atrial tissue. BACKGROUND: Obesity is associated with an increased risk of AF. METHODS: A total of 115 patients with AF who underwent AF ablation were screened. After exclusion, 26 patients were divided into 2 groups (obese: body mass index [BMI] ≥27 kg/m2 and reference: BMI <27 kg/m2). They underwent cardiac magnetic resonance (CMR) imaging and electroanatomic mapping of the left atrium (LA) in sinus rhythm before AF ablation. Atrial and ventricular epicardial adipose tissue (EAT) were assessed by CMR. The following electrophysiological parameters were assessed: global and regional voltage, conduction velocity (CV), electrogram fractionation, and CV heterogeneity. In addition, the regional relationship between LA EAT depots and the electrophysiological substrate was evaluated. RESULTS: The BMIs of the obese and reference groups were 30.2 ± 2.6 and 25.2 ± 1.3 kg/m2, respectively (p < 0.001). There was no difference in the left ventricular ejection fraction and a nonsignificant increase in LA size with obesity. Obesity was associated with increase in all measures of EAT (p < 0.05), with a predominant distribution adjacent to the posterior LA and the atrioventricular groove. Obesity was associated with reduced global CV (0.86 ± 0.31 m/s vs. 1.26 ± 0.29 m/s; p < 0.001), with a nonsignificant increase in conduction heterogeneity (p = 0.10), increased fractionation (54 ± 17% vs. 25 ± 10%; p < 0.001), and regional alteration in voltage (p < 0.001). Although the global LA voltage was preserved, there was greater voltage heterogeneity (p = 0.001) and increased low-voltage areas (13.9% vs. 3.4%; p < 0.001) in the obese group compared with the reference group. The low voltage areas were predominantly seen in the posterior and/or inferior LA, which was similar to location of EAT on CMR imaging. Among various measures of obesity, LA EAT volume correlated best with posterior LA fractionation (r2 = 0.55 for LA EAT volume vs. r2 = 0.36 for BMI) and CV (r2 = 0.31 for LA EAT volume vs. r2 = 0.22 for BMI). CONCLUSIONS: Obesity is associated with electroanatomical remodeling of the atria, with areas of low voltage, conduction slowing, and greater fractionation of electrograms. These changes were more pronounced in regions adjacent to epicardial fat depots, which suggested a role for fat depots in the development of the AF substrate. Crown
OBJECTIVES: The aims of the study were to characterize: 1) electrical and electroanatomical remodeling in patients with atrial fibrillation (AF) with obesity; and 2) the impact of epicardial fat depots on adjacent atrial tissue. BACKGROUND:Obesity is associated with an increased risk of AF. METHODS: A total of 115 patients with AF who underwent AF ablation were screened. After exclusion, 26 patients were divided into 2 groups (obese: body mass index [BMI] ≥27 kg/m2 and reference: BMI <27 kg/m2). They underwent cardiac magnetic resonance (CMR) imaging and electroanatomic mapping of the left atrium (LA) in sinus rhythm before AF ablation. Atrial and ventricular epicardial adipose tissue (EAT) were assessed by CMR. The following electrophysiological parameters were assessed: global and regional voltage, conduction velocity (CV), electrogram fractionation, and CV heterogeneity. In addition, the regional relationship between LA EAT depots and the electrophysiological substrate was evaluated. RESULTS: The BMIs of the obese and reference groups were 30.2 ± 2.6 and 25.2 ± 1.3 kg/m2, respectively (p < 0.001). There was no difference in the left ventricular ejection fraction and a nonsignificant increase in LA size with obesity. Obesity was associated with increase in all measures of EAT (p < 0.05), with a predominant distribution adjacent to the posterior LA and the atrioventricular groove. Obesity was associated with reduced global CV (0.86 ± 0.31 m/s vs. 1.26 ± 0.29 m/s; p < 0.001), with a nonsignificant increase in conduction heterogeneity (p = 0.10), increased fractionation (54 ± 17% vs. 25 ± 10%; p < 0.001), and regional alteration in voltage (p < 0.001). Although the global LA voltage was preserved, there was greater voltage heterogeneity (p = 0.001) and increased low-voltage areas (13.9% vs. 3.4%; p < 0.001) in the obese group compared with the reference group. The low voltage areas were predominantly seen in the posterior and/or inferior LA, which was similar to location of EAT on CMR imaging. Among various measures of obesity, LA EAT volume correlated best with posterior LA fractionation (r2 = 0.55 for LA EAT volume vs. r2 = 0.36 for BMI) and CV (r2 = 0.31 for LA EAT volume vs. r2 = 0.22 for BMI). CONCLUSIONS:Obesity is associated with electroanatomical remodeling of the atria, with areas of low voltage, conduction slowing, and greater fractionation of electrograms. These changes were more pronounced in regions adjacent to epicardial fat depots, which suggested a role for fat depots in the development of the AF substrate. Crown
Authors: Tiffany M Powell-Wiley; Paul Poirier; Lora E Burke; Jean-Pierre Després; Penny Gordon-Larsen; Carl J Lavie; Scott A Lear; Chiadi E Ndumele; Ian J Neeland; Prashanthan Sanders; Marie-Pierre St-Onge Journal: Circulation Date: 2021-04-22 Impact factor: 29.690
Authors: Anna Ostropolets; Pierre A Elias; Michael V Reyes; Elain Y Wan; Utpal B Pajvani; George Hripcsak; John P Morrow Journal: Circ Arrhythm Electrophysiol Date: 2021-02-07
Authors: Gijs van Woerden; Dirk J van Veldhuisen; Thomas M Gorter; Vanessa P M van Empel; Martin E W Hemels; Eric J Hazebroek; Sophie L van Veldhuisen; Tineke P Willems; Michiel Rienstra; Berend Daan Westenbrink Journal: Clin Cardiol Date: 2021-06-04 Impact factor: 2.882