Department of Biomedical Engineering, İzmir Demokrasi University, Izmir, Turkey.
Institute of Science and Engineering, Baskent University, Ankara, Turkey.
Dysphagia. 2021 Jun;36(3):402-408. doi: 10.1007/s00455-020-10150-x. Epub 2020 Jul 1.
Swallowing can lead to the development of syncope in people who have difficulty swallowing during food intake. It has shown that even spontaneous saliva swallowing can change heart rate variability (HRV). Recently, it has been suggested that changes in heart rate during swallowing may be caused by respiratory activities. In this study, the hypothesis that swallowing induced HRV are caused from breathing changes during swallowing has been tested. For this purpose, electrocardiogram (ECG), chest circumference (respiration) signals and swallowing sounds were recorded simultaneously from 20 subjects. Subjects were asked not to swallow their saliva in the first 4 min of the experiment and to swallow them several times in the next 4 min. To observe respiratory effects on HRV during swallowing, a detailed cardio-respiratory system mathematical model was used. By applying recorded chest circumference signal to the mathematical model, respiration induced HRV changes were obtained. The HRV parameters of with and without swallowing regions of the real (obtained from ECG) and model-HRV (obtained from mathematical model) were compared by paired Student t test. Statistical differences seen in the real-HRV between the swallowing and non-swallowing regions (SDNN, LF power, approximate entropy) were not observed in the model-HRV. Considering that the only factor constituting HRV in the mathematical model is respiration, it was concluded that swallowing changes HRV with a mechanism other than breathing changes.
吞咽可导致在进食时吞咽困难的人发生晕厥。有研究表明，即使是自发的唾液吞咽也可改变心率变异性（HRV）。最近有研究表明，吞咽过程中心率的变化可能是由呼吸活动引起的。在这项研究中，我们检验了吞咽诱导的 HRV 是由吞咽过程中的呼吸变化引起的假说。为此，我们从 20 名受试者同步记录了心电图（ECG）、胸围（呼吸）信号和吞咽声音。在实验的前 4 分钟，要求受试者不要吞咽唾液，在接下来的 4 分钟内多次吞咽。为了观察吞咽过程中心率变异性的呼吸影响，我们使用了详细的心肺系统数学模型。通过将记录的胸围信号应用于数学模型，我们获得了呼吸引起的 HRV 变化。通过配对学生 t 检验比较了真实 HRV（从 ECG 获得）和模型 HRV（从数学模型获得）的吞咽和非吞咽区域的 HRV 参数。在真实 HRV 中，在吞咽和非吞咽区域之间观察到的统计差异（SDNN、LF 功率、近似熵）在模型 HRV 中并未观察到。考虑到数学模型中构成 HRV 的唯一因素是呼吸，因此可以得出结论，吞咽改变 HRV 的机制不是呼吸变化。
