Vidrio H, Tena I
Clin Pharmacol Ther. 1980 Nov;28(5):587-91. doi: 10.1038/clpt.1980.207.
The correlation between hydralazine-induced tachycardia and overall cardiovascular reactivity to sympathetic stimulation was explored in 50 normal subjects. Blood pressure and heart rate changes after standing, immersion of a hand in cold water, the Valsalva maneuver, and moderate exercise were compared with pressure and rate responses to 20 mg oral hydralazine. The drug did not modify blood pressure but increased heart rate, mainly in the standing position. Because plotting the magnitude of this response suggested a two-population distribution, subjects were divided into hyporeactor and hyperreactor groups. Reactivity did not appear to be related to acetylator phenotype. The magnitude of the cardiac response correlated with heart rate responses to standing and to the Valsalva maneuver; when analyzed separately from hyporeactors, correlation was greater among hyperreactors. Because the orthostatic and Valsalva responses are reflex in nature, these results suggest that hydralazine tachycardia is also reflexly induced, that its magnitude depends on individual baroreceptor sensitivity, which is distributed nonnormally, and that it can be predicted by suitable tests of sympathetic responsiveness.
在50名正常受试者中探讨了肼屈嗪诱发的心动过速与对交感神经刺激的整体心血管反应性之间的相关性。将站立、手浸入冷水中、瓦尔萨尔瓦动作和适度运动后的血压和心率变化与口服20毫克肼屈嗪后的压力和心率反应进行比较。该药物未改变血压，但增加了心率，主要是在站立位时。由于绘制这种反应的幅度显示出双峰分布，受试者被分为低反应者和高反应者组。反应性似乎与乙酰化表型无关。心脏反应的幅度与站立和瓦尔萨尔瓦动作时的心率反应相关；当与低反应者分开分析时，高反应者之间的相关性更强。由于直立和瓦尔萨尔瓦反应本质上是反射性的，这些结果表明肼屈嗪诱发的心动过速也是反射性诱发的，其幅度取决于个体压力感受器的敏感性，这种敏感性呈非正态分布，并且可以通过适当的交感反应性测试来预测。
