National Heart & Lung Institute (NHLI), Imperial College London, London, United Kingdom.
Medical Research Council London Laboratory of Medical Sciences, London, United Kingdom.
Heart Rhythm. 2024 Nov;21(11):2282-2294. doi: 10.1016/j.hrthm.2024.05.052. Epub 2024 May 31.
Obesity confers higher risks of cardiac arrhythmias. The extent to which weight loss reverses subclinical proarrhythmic adaptations in arrhythmia-free obese individuals is unknown.
The purpose of this study was to study structural, electrophysiological, and autonomic remodeling in arrhythmia-free obese patients and their reversibility with bariatric surgery using electrocardiographic imaging (ECGi).
Sixteen arrhythmia-free obese patients (mean age 43 ± 12 years; 13 (81%) female participants; BMI 46.7 ± 5.5 kg/m) had ECGi pre-bariatric surgery, of whom 12 (75%) had ECGi postsurgery (BMI 36.8 ± 6.5 kg/m). Sixteen age- and sex-matched lean healthy individuals (mean age 42 ± 11 years; BMI 22.8 ± 2.6 kg/m) acted as controls and had ECGi only once.
Obesity was associated with structural (increased epicardial fat volumes and left ventricular mass), autonomic (blunted heart rate variability), and electrophysiological (slower atrial conduction and steeper ventricular repolarization time gradients) remodeling. After bariatric surgery, there was partial structural reverse remodeling, with a reduction in epicardial fat volumes (68.7 cm vs 64.5 cm; P = .0010) and left ventricular mass (33 g/m vs 25 g/m; P < .0005). There was also partial electrophysiological reverse remodeling with a reduction in mean spatial ventricular repolarization gradients (26 mm/ms vs 19 mm/ms; P = .0009), although atrial activation remained prolonged. Heart rate variability, quantified by standard deviation of successive differences in R-R intervals, was also partially improved after bariatric surgery (18.7 ms vs 25.9 ms; P = .017). Computational modeling showed that presurgical obese hearts had a larger window of vulnerability to unidirectional block and had an earlier spiral-wave breakup with more complex reentry patterns than did postsurgery counterparts.
Obesity is associated with adverse electrophysiological, structural, and autonomic remodeling that is partially reversed after bariatric surgery. These data have important implications for bariatric surgery weight thresholds and weight loss strategies.
肥胖会增加心律失常的风险。在不伴有心律失常的肥胖个体中，减轻体重是否能逆转亚临床致心律失常适应性尚不清楚。
本研究旨在使用心电图影像（ECGi）研究不伴有心律失常的肥胖患者的结构、电生理和自主神经重构，以及减重手术对此类重构的逆转作用。
16 名不伴有心律失常的肥胖患者（平均年龄 43±12 岁；13 名（81%）为女性；BMI 46.7±5.5kg/m2）在减重手术前进行了 ECGi 检查，其中 12 名（75%）在手术后进行了 ECGi 检查（BMI 36.8±6.5kg/m2）。16 名年龄和性别匹配的健康瘦人（平均年龄 42±11 岁；BMI 22.8±2.6kg/m2）作为对照组，仅进行了一次 ECGi 检查。
肥胖与结构（心外膜脂肪体积增加和左心室质量增加）、自主神经（心率变异性减弱）和电生理（心房传导减慢和心室复极时间梯度变陡）重构有关。减重手术后，部分结构出现逆转重构，心外膜脂肪体积减少（68.7cm 比 64.5cm；P=0.0010），左心室质量减少（33g/m 比 25g/m；P<0.0005）。电生理重构也部分逆转，平均空间心室复极梯度降低（26mm/ms 比 19mm/ms；P=0.0009），尽管心房激活仍延长。通过逐次 R-R 间期差异的标准差来量化心率变异性，减重手术后也得到部分改善（18.7ms 比 25.9ms；P=0.017）。计算模型显示，术前肥胖心脏的单向阻滞易损窗口更大，螺旋波破裂更早，折返模式更复杂。
肥胖与不良的电生理、结构和自主神经重构有关，减重手术后这些重构可部分逆转。这些数据对减重手术的体重阈值和减肥策略具有重要意义。
