Marthol H, Tutaj M, Brys M, Brown C M, Hecht M J, Berlin D, Axelrod F B, Hilz M J
Department of Neurology, New York University School of Medicine, New York, NY, USA.
Eur J Clin Invest. 2003 Oct;33(10):912-8. doi: 10.1046/j.1365-2362.2003.01242.x.
Patients with familial dysautonomia (FD) frequently experience hypertensive crises after gastrostomy feeding. The central alpha2-agonist clonidine attenuates feeding-induced crises. The aim of this study was to assess the effect of clonidine on cardiovascular autonomic modulation and particularly baroreflex sensitivity in familial dysautonomia after gastrostomy feeding.
In nine patients, we monitored the RR-interval and systolic blood pressure at supine rest before (baseline 1) and after gastrostomy feeding (GF1). One day later, recordings were repeated after clonidine intake (baseline 2, GF2). We determined spectral powers of RR-interval and systolic blood pressure in the low- (LF) and high-frequency range (HF). Sympathovagal balance was determined from the LF/HF ratio of RR-interval. Baroreflex sensitivity was assessed from the alpha-index of systolic blood pressure and RR-interval.
Gastrostomy feeding decreased RR-interval, while systolic blood pressure remained stable. Clonidine induced higher RR-intervals before and after gastrostomy feeding but decreased systolic blood pressure at baseline only. Gastrostomy feeding decreased HF-power of RR-interval significantly without clonidine, but only slightly after premedication. Clonidine increased the HF-power of RR-interval slightly at baseline and significantly after gastrostomy feeding. Gastrostomy feeding increased the LF/HF ratio without clonidine only. Clonidine decreased the LF/HF ratio at baseline and after gastrostomy feeding. Gastrostomy feeding did not change baroreflex sensitivity, but baroreflex sensitivity was higher at visit 2 than visit 1.
In familial dysautonomia, clonidine augments baroreflex sensitivity and parasympathetic modulation. The resulting cardiovascular stabilization might attenuate feeding-induced crises.
家族性自主神经功能障碍（FD）患者在胃造口喂养后经常发生高血压危象。中枢α2受体激动剂可乐定可减轻喂养引起的危象。本研究的目的是评估可乐定对胃造口喂养后家族性自主神经功能障碍患者心血管自主调节的影响，尤其是压力反射敏感性。
对9例患者，我们在胃造口喂养前（基线1）和喂养后（GF1）仰卧休息时监测RR间期和收缩压。一天后，在摄入可乐定后重复记录（基线2，GF2）。我们测定了RR间期和收缩压在低频（LF）和高频范围（HF）的频谱功率。通过RR间期的LF/HF比值确定交感迷走神经平衡。通过收缩压和RR间期的α指数评估压力反射敏感性。
胃造口喂养使RR间期缩短，而收缩压保持稳定。可乐定在胃造口喂养前后使RR间期延长，但仅在基线时降低收缩压。胃造口喂养在未使用可乐定时显著降低RR间期的HF功率，但在用药前仅略有降低。可乐定在基线时使RR间期的HF功率略有增加，在胃造口喂养后显著增加。胃造口喂养仅在未使用可乐定时增加LF/HF比值。可乐定在基线和胃造口喂养后降低LF/HF比值。胃造口喂养未改变压力反射敏感性，但在第2次就诊时压力反射敏感性高于第1次就诊。
在家族性自主神经功能障碍中，可乐定增强压力反射敏感性和副交感神经调节。由此产生的心血管稳定可能减轻喂养引起的危象。
