Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
Department of Radiation Sciences, Radiation Physics, Biomedical Engineering, Umeå University, Umeå, Sweden.
PLoS One. 2023 Dec 7;18(12):e0295431. doi: 10.1371/journal.pone.0295431. eCollection 2023.
Swimming is a genotype-specific trigger in long QT syndrome type 1 (LQT1).
To examine the autonomic response to water activities in children and adolescents with LQT1.
In this cross-sectional study, LQT1 patients were age and sex matched to one healthy control subject. Electrocardiograms (ECGs) were recorded during face immersion (FI), swimming, diving, and whole-body submersion (WBS). Heart rate (HR) and heart rate variability (HRV) was measured. The high frequency (HF) component of HRV was interpreted to reflect parasympathetic activity, while the low frequency (LF) component was interpreted as reflecting the combined influence of sympathetic and parasympathetic activity on autonomic nervous modulation of the heart.
Fifteen LQT1 patients (aged 7-19 years, all on beta-blocker therapy) and fifteen age and sex matched non-medicated controls were included. No significant ventricular arrhythmias were observed in the LQT1 population during the water activities. Out of these 15 matched pairs, 12 pairs managed to complete FI and WBS for more than 10 seconds and were subsequently included in HR and HRV analyses. In response to FI, the LQT1 group experienced a drop in HR of 48 bpm, compared to 67 bpm in the control group (p = 0.006). In response to WBS, HR decreased by 48 bpm in the LQT1 group and 70 bpm in the control group (p = 0.007). A significantly lower PTOT (p < 0.001) and HF (p = 0.011) component was observed before, during and after FI in LQT1 patients compared with the controls. Before, during and after WBS, a significantly lower total power (p < 0.001), LF (p = 0.002) and HF (p = 0.006) component was observed in the LQT1 patients.
A significantly lower HR decrease in response to water activities was observed in LQT1 subjects on beta-blocker therapy, compared to matched non-medicated controls. The data suggests an impaired parasympathetic response in LQT1 children and adolescents. An aberrant autonomic nervous system (ANS) response may cause an autonomic imbalance in this patient group.
在长 QT 综合征 1 型（LQT1）中，游泳是一种特定于基因型的触发因素。
研究 LQT1 患儿对水活动的自主神经反应。
在这项横断面研究中，LQT1 患者与一名健康对照者按年龄和性别匹配。在面部浸入（FI）、游泳、潜水和全身浸没（WBS）期间记录心电图（ECG）。测量心率（HR）和心率变异性（HRV）。HRV 的高频（HF）成分被解释为反映副交感神经活动，而低频（LF）成分被解释为反映交感神经和副交感神经对心脏自主神经调节的综合影响。
纳入了 15 名 LQT1 患者（年龄 7-19 岁，均接受β受体阻滞剂治疗）和 15 名年龄和性别匹配的未用药对照者。在 LQT1 人群中，在水活动期间未观察到明显的室性心律失常。在这 15 对匹配的患者中，有 12 对能够完成 FI 和 WBS 超过 10 秒，随后被纳入 HR 和 HRV 分析。在 FI 反应中，LQT1 组的 HR 下降 48 次/分，而对照组为 67 次/分（p=0.006）。在 WBS 反应中，LQT1 组的 HR 下降 48 次/分，对照组下降 70 次/分（p=0.007）。与对照组相比，LQT1 患者在 FI 前、中、后，PTOT（p<0.001）和 HF（p=0.011）成分明显降低。在 WBS 前、中、后，LQT1 患者的总功率（p<0.001）、LF（p=0.002）和 HF（p=0.006）成分明显降低。
与匹配的未用药对照组相比，接受β受体阻滞剂治疗的 LQT1 患者对水活动的 HR 降低反应明显降低。数据表明，LQT1 儿童和青少年的副交感神经反应受损。自主神经系统（ANS）的异常反应可能导致该患者群体的自主神经失衡。
