Department of Surgery, Morriston Hospital, Swansea.
Auton Neurosci. 2009 Dec 3;151(2):168-73. doi: 10.1016/j.autneu.2009.08.007. Epub 2009 Aug 31.
Obesity is associated with reduced heart rate variability (HRV), reflecting detrimental changes in cardiac regulation by the autonomic nervous system (ANS). Weight loss reverses this change and ANS dysfunction is thought to have a role in obesity-related cardiac pathology. Few studies have examined the influence of weight-reduction (bariatric) surgery on cardiac autonomic control. This study therefore sought to assess longitudinal changes in indices of cardiac autonomic control following two types of bariatric procedure, laparascopic gastric banding (LGB) and biliopancreatic diversion (BPD).
Eleven morbidly obese subjects aged 47.8 +/- 7.9 years (mean+/-SD) with BMI 48.2 +/- 6.9 kg x m(-2) underwent weight-reduction surgery: five received BPD and six received LGB. Holter ECG was recorded and HRV was quantified together with a QT variability index (QTVI), a complexity index (SampEn), and a fractal (scaling) index (DFAalpha). Repeated measures ANOVA compared the indices for the two groups as a function of time (1, 6 and 12 months follow-up).
BMI was reduced by up to 24% (p=0.008) post-surgery despite patients remaining obese at one-year follow-up. Several indices showed prompt and persistent improvement with progressive weight loss, QTVI being the most sensitive discriminator of recovery time (F(3,216)=16.86; p<0.0005; eta(2)=0.190). Autonomic responsiveness was functionally normal throughout. The bariatric procedures induced similar changes in cardiac autonomic control, despite their differing mechanisms of action.
This pilot study suggests that the mechanism responsible for improving cardiac regulation following bariatric surgery might be the weight loss itself. Furthermore, post-surgery improvement in QTVI implies that weight loss reduces the risk of ventricular arrhythmic events.
肥胖与心率变异性（HRV）降低有关，反映了自主神经系统（ANS）对心脏调节的不利变化。减肥可以逆转这种变化，并且认为自主神经功能障碍在肥胖相关的心脏病理学中起作用。很少有研究检查减肥（减肥）手术对心脏自主控制的影响。因此，本研究旨在评估两种减肥手术（腹腔镜胃带术（LGB）和胆胰分流术（BPD）后心脏自主控制指数的纵向变化。
11 名年龄 47.8+/-7.9 岁（均值+/-SD）、BMI 48.2+/-6.9kg x m(-2)的病态肥胖患者接受了减肥手术：5 名患者接受了 BPD，6 名患者接受了 LGB。进行了动态心电图记录，并量化了心率变异性，同时还量化了 QT 变异性指数（QTVI）、复杂度指数（SampEn）和分形（标度）指数（DFAalpha）。重复测量方差分析比较了两组作为时间函数的指数（1、6 和 12 个月随访）。
尽管患者在一年随访时仍然肥胖，但手术后 BMI 降低了多达 24%（p=0.008）。尽管手术后 BMI 降低了多达 24%（p=0.008），但一些指数显示出迅速而持续的改善，与体重持续下降有关，QTVI 是恢复时间最敏感的判别指标（F（3，216）=16.86；p<0.0005；eta(2)=0.190）。自主反应在整个过程中均正常。尽管两种减肥手术的作用机制不同，但它们对心脏自主控制的影响相似。
这项初步研究表明，减肥手术改善心脏调节的机制可能是体重减轻本身。此外，手术后 QTVI 的改善意味着体重减轻降低了室性心律失常事件的风险。
