Nematzadeh D, Kim Y D, Rose J C, Wolf P H, Macnamara T E, Kot P A
Cardiovasc Res. 1986 Apr;20(4):275-81. doi: 10.1093/cvr/20.4.275.
In the intact canine heart a gradient of systolic intramyocardial pressure from a minimum at the epicardial region to a maximum at the endocardial region is well established. No information is, however, available regarding the effects of various anaesthetic agents on this gradient. In the present study the effects of halothane on intramyocardial pressure recorded from subendocardial and subepicardial layers of the canine left ventricular free wall were assessed. Experiments were performed on seven anaesthetised mongrel dogs ventilated with 100% oxygen. Intramyocardial pressure was recorded simultaneously from the inner and outer regions of the myocardium using two Mikro-tip pressure transducers. Halothane concentration in the inspired gas varied from 0% to 2%. In the pentobarbital anaesthetised dog halothane does not significantly change the heart rate. With increasing concentrations of halothane in inspired gas systolic intramyocardial pressure at both endocardium and epicardium decreased significantly from control values. As the halothane concentration increased, the normal differential between systolic left ventricular pressure and endocardial intramyocardial pressure was abolished. The intramyocardial pressure gradient from endocardium to epicardium, however, persisted during systole. During diastole the pressure gradient was reversed, becoming maximum in the epicardial region and minimum in the endocardial region in both control and halothane treated animals. Over the range of 0-2% halothane concentration there was no significant effect on the diastolic intramyocardial pressure gradient. These results suggest that halothane affects the myocardial tissue pressure non-uniformly across the left ventricular free wall and therefore influence sth e transmural distribution of coronary blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)
在完整的犬心脏中，收缩期心肌内压力从心外膜区域的最小值到心内膜区域的最大值的梯度已得到充分证实。然而，关于各种麻醉剂对该梯度的影响尚无相关信息。在本研究中，评估了氟烷对犬左心室游离壁心内膜下和心外膜下层记录的心肌内压力的影响。实验在七只吸入100%氧气通气的麻醉杂种犬身上进行。使用两个微型尖端压力传感器同时记录心肌内外区域的心肌内压力。吸入气体中的氟烷浓度从0%变化到2%。在戊巴比妥麻醉的犬中，氟烷不会显著改变心率。随着吸入气体中氟烷浓度的增加，心内膜和心外膜的收缩期心肌内压力均较对照值显著降低。随着氟烷浓度的增加，收缩期左心室压力与心内膜心肌内压力之间的正常差异消失。然而，在收缩期，从心内膜到心外膜的心肌内压力梯度仍然存在。在舒张期，压力梯度反转，在对照动物和氟烷处理的动物中，心外膜区域最大，心内膜区域最小。在0 - 2%的氟烷浓度范围内，对舒张期心肌内压力梯度没有显著影响。这些结果表明，氟烷对左心室游离壁的心肌组织压力影响不均一，因此影响冠状动脉血流的跨壁分布。（摘要截短至250字）
