Fukuma Nagaharu, Kato Kazuyo, Munakata Kazuo, Hayashi Hiroko, Kato Yuko, Aisu Noriko, Takahashi Hiroshi, Mabuchi Kousuke, Mizuno Kyoichi
Cardiology Department of internal medicine, Nippon Medical School, Tokyo, Japan.
Clin Physiol Funct Imaging. 2012 Jul;32(4):305-9. doi: 10.1111/j.1475-097X.2012.01127.x. Epub 2012 Mar 26.
Past reports showed that the baroreflex continuously regulates hemodynamics during exercise. However, it is still clinically unclear. If baroreflex mechanism is able to influence actually exercise cardiovascular control, baroreflex sympathetic and/or parasympathetic function relates to response to exercise. Therefore, we examined the relationship of heat rate changes to both blood pressure increment and decrement with tolerance and chronotropic response to peak exercise in patients with heart disease.
In 25 male heart disease patients (60 ± 9 years) without decompensated heart failure, baroreceptor reflex sensitivity (BRS ms mmHg(-1) ) was measured by reflex heart rate responses to changes in blood pressure after phenylephrine (P-BRS) and nitroglycerin (N-BRS) injection, respectively. Symptom-limited treadmill exercise test was performed according to Bruce's protocol.
(i) The absolute values of blood pressure change after the administrations were similar between the agents because the dosages of nitroglycerin and phenylephrine were set to equalize absolute changes in blood pressure. (ii) In this study population, the ratio of N-BRS to P-BRS was not significantly correlated with hypertension and diabetes mellitus. (iii) Exercise capacity (METs) (r= -0.626) and heart rate response to exercise per METs (r=0.670) was significantly related to N-BRS but not to P-BRS.
We found that the abnormality of baroreflex function in the presence of blood pressure decrements can lead to insufficient capacity and easy sympathetic activation during exercise.
既往报道显示，压力反射在运动过程中持续调节血流动力学。然而，在临床上仍不明确。如果压力反射机制能够实际影响运动心血管控制，那么压力反射的交感神经和/或副交感神经功能与运动反应相关。因此，我们研究了心脏病患者心率变化与血压升高和降低以及运动耐力和运动峰值时变时性反应之间的关系。
对25例无失代偿性心力衰竭的男性心脏病患者（60±9岁），分别通过注射去氧肾上腺素（P-BRS）和硝酸甘油（N-BRS）后血压变化所引起的反射性心率反应来测量压力感受器反射敏感性（BRS，ms mmHg⁻¹）。根据布鲁斯方案进行症状限制性平板运动试验。
（i）由于硝酸甘油和去氧肾上腺素的剂量设定为使血压的绝对变化相等，给药后血压变化的绝对值在两种药物之间相似。（ii）在本研究人群中，N-BRS与P-BRS的比值与高血压和糖尿病无显著相关性。（iii）运动能力（代谢当量）（r = -0.626）和每代谢当量运动时的心率反应（r = 0.670）与N-BRS显著相关，而与P-BRS无关。
我们发现，在存在血压下降的情况下，压力反射功能异常可导致运动能力不足和运动期间易于交感神经激活。
