Wu Shuang, Guan Weizheng, Zhao Huan, Li Guangqiao, Zhou Yufu, Shi Bo, Zhang Xiaochun
School of Medicine, Yangzhou University, Yangzhou, China.
Department of Radiation Oncology, First Affiliated Hospital, Bengbu Medical College, Bengbu, China.
Front Neurosci. 2023 Sep 4;17:1256067. doi: 10.3389/fnins.2023.1256067. eCollection 2023.
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], = 0.002) and HRV parameters SDNN (9.9 [7.03, 16.0] vs. 8.2 [6.0, 12.4], = 0.003), RMSSD (9.9 [6.9, 17.5] vs. 7.7 [4.8, 14.3], = 0.009), LF (29 [10, 135] vs. 24 [15, 50], = 0.005), HF (35 [12, 101] vs. 16 [9, 46], = 0.002), TP (74 [41, 273] vs. 50 [33, 118], < 0.001), and a significant increase in AC (-8.2 [-14.8, -4.9] vs. -5.8 [-10.1, -3.3], = 0.003) and mean heart rate (79.8 ± 12.6 vs. 83.9 ± 13.6, = 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.
先前的研究表明，心血管自主神经功能障碍可能是抗肿瘤治疗所致心脏毒性的早期标志物，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，胸部放疗对副交感神经和交感神经系统的影响仍不清楚。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，评估胸部放疗对自主神经系统的短期影响。
收集58例胸段癌症患者在胸部放疗前后的5分钟心电图，用于DC、AC和HRV分析。所采用的HRV参数包括正常到正常间期的标准差（SDNN）、连续间期差值的均方根（RMSSD）、低频功率（LF）、高频功率（HF）、总功率（TP）以及LF与HF比值。部分患者在放疗的同时还接受了全身治疗；因此，将患者分为单纯放疗组（28例）和放疗联合全身治疗组（30例）进行进一步的亚组分析。
胸部放疗导致DC显著降低（8.5[5.0，14.2]对5.3[3.5，9.4]，P = 0.002）以及HRV参数SDNN（9.9[7.03，16.0]对8.2[6.0，12.4]，P = 0.003）、RMSSD（9.9[6.9，17.5]对7.7[4.8，14.3]，P = 0.009）、LF（29[10，135]对24[15，50]，P = 0.005）、HF（35[12，101]对16[9，46]，P = 0.002）、TP（74[41，273]对50[33，118]，P < 0.001），并导致AC显著增加（-8.2[-14.8，-4.9]对-5.8[-10.1，-3.3]，P = 0.00）以及平均心率增加（79.8±12.6对83.9±13.6，P = 0.010）。亚组分析表明，放疗组和联合治疗组放疗后平均心率及DC、AC和HRV参数（SDNN、RMSSD、LF、HF、TP）呈现相似趋势。放疗前后两组间DC、AC和HRV的变化无统计学显著差异。
胸部放疗可能通过降低副交感神经活性和增强交感神经活性而诱发心血管自主神经功能障碍。重要的是，该研究发现，在胸部放疗后的短期内，同时使用全身治疗并未显著放大或导致自主神经功能的改变。DC、AC和HRV是评估胸部放疗所致自主神经功能障碍的有前景且可行的生物标志物。
