早期研究表明，心血管自主神经功能失调可能是抗肿瘤治疗引起心脏毒性的早期标志，并可作为心血管疾病相关发病率和死亡率的早期预测指标。然而，胸部放射治疗对副交感神经和交感神经系统的影响尚不清楚。因此，本研究旨在使用心率减速能力（DC）、心率加速能力（AC）和心率变异性（HRV）作为评估工具，评估胸部放射治疗对自主神经系统的短期影响。通过收集58名胸部癌症患者的5分钟心电图，分别在胸部放射治疗前后进行DC、AC和HRV分析。使用的HRV参数包括正常-正常间期的标准差（SDNN）、连续间期差的均方根（RMSSD）、低频功率（LF）、高频功率（HF）、总功率（TP）以及LF和HF的比值。部分患者在接受放疗同时也接受全身治疗，因此将患者分为只接受放疗组（28例）和放疗联合全身治疗组（30例）进行额外的亚组分析。胸部放射治疗导致DC（8.5 [5.0, 14.2] vs. 5.3 [3.5, 9.4], p = 0.002）以及HRV参数SDNN（9.9 [7.03, 16.0] vs. 8.2 [6.0, 12.4], p = 0.003）、RMSSD（9.9 [6.9, 17.5] vs. 7.7 [4.8, 14.3], p = 0.009）、LF（29 [10, 135] vs. 24 [15, 50], p = 0.005）、HF（35 [12, 101] vs. 16 [9, 46], p = 0.002）、TP（74 [41, 273] vs. 50 [33, 118], p < 0.001）显著降低，同时AC（-8.2 [-14.8, -4.9] vs. -5.8 [-10.1, -3.3], p = 0.003）和平均心率（79.8 ± 12.6 vs. 83.9 ± 13.6, p = 0.010）显著增加。亚组分析表明，放疗组和联合治疗组中，平均心率、DC、AC和HRV参数（SDNN、RMSSD、LF、HF、TP）在放疗后均呈相似趋势。放疗前后两组在DC、AC和HRV变化方面没有统计学显著差异。胸部放射治疗可能通过降低副交感神经活动和增强交感神经活动引起心血管自主神经功能失调。重要的是，本研究发现，在胸部放射治疗后的短期内，全身治疗的同时使用并未显著增强或导致自主功能异常的变化。DC、AC和HRV是评估胸部放射治疗引起自主神经功能异常的有前景且可行的生物标志物。版权所有 © 2023 武、管、赵、李、周、史和张。

Prior research suggests that cardiovascular autonomic dysfunction might be an early marker of cardiotoxicity induced by antitumor treatment and act as an early predictor of cardiovascular disease-related morbidity and mortality. The impact of thoracic radiotherapy on the parasympathetic and sympathetic nervous systems, however, remains unclear. Therefore, this study aimed to evaluate the short-term effects of thoracic radiotherapy on the autonomic nervous system, using deceleration capacity (DC), acceleration capacity (AC) of heart rate, and heart rate variability (HRV) as assessment tools.A 5 min electrocardiogram was collected from 58 thoracic cancer patients before and after thoracic radiotherapy for DC, AC, and HRV analysis. HRV parameters employed included the standard deviation of the normal-normal interval (SDNN), root mean square of successive interval differences (RMSSD), low frequency power (LF), high frequency power (HF), total power (TP), and the LF to HF ratio. Some patients also received systemic therapies alongside radiotherapy; thus, patients were subdivided into a radiotherapy-only group (28 cases) and a combined radiotherapy and systemic therapies group (30 cases) for additional subgroup analysis.Thoracic radiotherapy resulted in a significant reduction in DC (8.5 [5.0, 14.2] vs. 5.3 [3.5, 9.4], p = 0.002) and HRV parameters SDNN (9.9 [7.03, 16.0] vs. 8.2 [6.0, 12.4], p = 0.003), RMSSD (9.9 [6.9, 17.5] vs. 7.7 [4.8, 14.3], p = 0.009), LF (29 [10, 135] vs. 24 [15, 50], p = 0.005), HF (35 [12, 101] vs. 16 [9, 46], p = 0.002), TP (74 [41, 273] vs. 50 [33, 118], p < 0.001), and a significant increase in AC (-8.2 [-14.8, -4.9] vs. -5.8 [-10.1, -3.3], p = 0.003) and mean heart rate (79.8 ± 12.6 vs. 83.9 ± 13.6, p = 0.010). Subgroup analysis indicated similar trends in mean heart rate, DC, AC, and HRV parameters (SDNN, RMSSD, LF, HF, TP) in both the radiotherapy group and the combined treatment group post-radiotherapy. No statistically significant difference was noted in the changes observed in DC, AC, and HRV between the two groups pre- and post-radiotherapy.Thoracic radiotherapy may induce cardiovascular autonomic dysfunction by reducing parasympathetic activity and enhancing sympathetic activity. Importantly, the study found that the concurrent use of systemic therapies did not significantly amplify or contribute to the alterations in autonomic function in the short-term following thoracic radiotherapy. DC, AC and HRV are promising and feasible biomarkers for evaluating autonomic dysfunction caused by thoracic radiotherapy.Copyright © 2023 Wu, Guan, Zhao, Li, Zhou, Shi and Zhang.