中文摘要：

目的探讨鼻咽癌（NPC）患者放疗前后心率变异性（HRV）及对胃排空功能的影响。方法应用24h动态心电图及口服钡条对30例NPC患者放疗前、放疗中和放疗后24hHRV时域指标和频域指标以及5h胃排空率进行检测分析。结果（1）NPC患者放疗前、放疗中和放疗后HRV分析比较表明：①时域指标SDNN、rMSSD和pNN50差异有统计学意义（P〈0．01）；两两比较后，SDNN放疗后显著低于放疗前和放疗中（P〈0．01或〈0．05），rMSSD和pNN50放疗后显著低于放疗前（P〈0．01），与放疗中比较差异无统计学意义（P〉0．05）。②频域指标LF、HF和TP差异有统计学意义（P〈0．05）；两两比较后，LF放疗后显著低于放疗前和放疗中（P均〈0．05），HF和TP放疗后显著低于放疗前（P〈0．05），与放疗中比较差异无统计学意义（P〉0．05）。（2）胃排空率检测分析表明：放疗前、放疔中和放疗后5h胃排空率差异有统计学意义（P〈0．05）；两两比较后，胃排空率放疗后显著低于放疗前（P〈0．01），与放疗中比较差异无统计学意义（P〉0．05）。结论NPC患者放射治疗随着照射剂量增加HRV降低越显著，提示鼻咽癌患者放疗后可能通过抑制迷走神经活性，影响交感一迷走神经平衡，从而影响自主神经调节，导致胃排空功能下降。

英文摘要：

Objective To explore the clinical significance of detection of heart rate variability （HRV） and gastric emptying in nasopharyngeal carcinoma（NPC） patients after radiotherapy. Methods 24-hour hoher recordings were detected for analysis of time domain and frequency domain index of HRV and the evaluation of the gastric emptying was performed using barium stick in 30 NPC patients in before-radiotherapy, mid-radiotherapy and after-radiotherapy. Results There were all results of HRV in 30 NPC cases after radiotherapy as followed ： （ 1 ） There was statistical significance in the time domain index（ SDNN, rMSSD,pNN50） comparison of three stages radiotherapy （P 〈 0. 01 ）. Compared with the before-radiotherapy and mid-radiotherapy,SDNN was lower in after-radiotherapy （P 〈 0. 01 or P 〈 0. 05 ） ; rMSSD and pNN50 in after-radiotherapy was lower than in before-radiotherapy （ P 〈 0. 01 ） ; （2） There was statistical significance in the frequency domain index （LF, HF, TP） comparison of three stages radiotherapy （P 〈 0. 05 ）. Compared with the before-radiotherapy and mid-radiotherapy, LF was lower in after-radiotherapy （ P 〈 0. 05） ; HF and TP in after-radiotherapy was lower than in before-radiotherapy （ P 〈 0. 05 ）. （ 3 ） There was statistical significance in 5-hour gastric emptying rate comparison of three stages radiotherapy（P 〈 0. 05） ;5-hour gastric emptying rate in after-radiotherapy was lower than in before-radiotherapy （P 〈 0. 01 ）. Conclusion HRV of NPC patients has be- come significantly decreasing with increasing of radiation doses. It indicates that the activity of vagus nerves is inhibited after radiotherapy in NPC patients,and has effect on sympathetic-vagal balance and autonomic nerves regulation. This leads to the decreasing of the gastric emptying.