Goyal Manish, Shukla Pragya, Gupta Deepak, Bisht Shyam, Verma Nar Singh, Tiwari Sunita, Bhatt Madan Lal
a Department of Physiology , All India Institute of Medical Sciences Bhubaneswar , Bhubaneswar , Odisha , India.
b Department of Clinical Oncology , Delhi State Cancer Institute , New Delhi , India.
Int J Radiat Biol. 2017 Jul;93(7):711-716. doi: 10.1080/09553002.2017.1303217. Epub 2017 Apr 28.
The baroreflex is an important afferent mechanism controlling autonomic functions. As afferent nerves course through the neck, they are susceptible to damage by neck irradiation in head and neck cancer patients. With increased survival of head and neck cancer patients because of improved therapy, the cardiovascular morbidity and mortality in them have become apparent and this is of clinical concern. There are few case reports of baroreflex failure as a chronic sequel to neck irradiation.
The present study evaluated the changes in cardio-autonomic tone and postural cardiovascular reflex in neck-irradiated patients.
Head and neck cancer patients who had received neck irradiation (n = 15) and healthy controls (n = 15) were evaluated for heart rate variability with time domain analysis of 5 min ECG recording. Postural cardiovascular reflexes were studied with changes in blood pressure and heart rate in the lying to standing test.
Our results suggest that there is a reduction in overall time domain measures of heart rate variability and weakened postural reflexes in neck-irradiated patients.
Decreased heart rate variability in neck-irradiated patients reflects an independent risk of cardiovascular morbidity. The early detection of cardiovascular impairment in such patients may help healthcare professionals in providing better care. Furthermore, the dose delivered to the carotid sinus should be monitored and restricted.
压力反射是控制自主神经功能的重要传入机制。由于传入神经在颈部走行，头颈部癌症患者的颈部放疗易损伤这些神经。随着头颈部癌症患者因治疗改善而生存率提高，其心血管疾病的发病率和死亡率已变得明显，这是临床关注的问题。作为颈部放疗慢性后遗症的压力反射衰竭的病例报告很少。
本研究评估颈部放疗患者心脏自主神经张力和姿势性心血管反射的变化。
对接受颈部放疗的头颈部癌症患者（n = 15）和健康对照者（n = 15）进行评估，通过对5分钟心电图记录进行时域分析来评估心率变异性。通过卧立位试验中血压和心率的变化研究姿势性心血管反射。
我们的结果表明，颈部放疗患者的心率变异性总体时域测量值降低，姿势反射减弱。
颈部放疗患者心率变异性降低反映了心血管疾病发病的独立风险。在此类患者中早期发现心血管损害可能有助于医护人员提供更好的护理。此外，应监测并限制给予颈动脉窦的剂量。
