Norepinephrine release by ventricular stimulation: effect on fibrillation thresholds.
Norepinephrine release by ventricular stimulation: effect on fibrillation thresholds.
复制标题
心室刺激释放去甲肾上腺素：对颤动阈值的影响。
DOI：
10.1152/ajpheart.1980.238.3.h406
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
D. Euler
中科院分区：
文献类型：
--
作者：
D. Euler
在戊巴比妥钠麻醉的成年犬中，用14列脉冲（4 ms, 100 Hz）扫描易损期测定的心室颤动阈值显著低于单次10 ms刺激扫描易损期测定的心室颤动阈值（P < 0.01）。用普萘洛尔阻断β -肾上腺素能后，心室颤动阈值的相对升高是单刺激阈值相对升高的7倍（P < 0.01）。在一组遭受慢性心脏去神经支配的动物中，用火车测量的纤颤阈值大约是一组开胸动物的三倍（P < 0.01）。此外，儿茶酚胺衰竭心脏的列车颤阈值与β -阻断神经支配心脏的列车阈值无显著差异。这些数据，再加上刺激序列对局部心肌收缩力产生显著增强的发现，表明在测定纤颤阈值期间局部释放的去甲肾上腺素可能对引起纤颤所需的电流水平产生深远的影响。
In adult dogs anesthetized with pentobarbital sodium, ventricular fibrillation thresholds determined by scanning the vulnerable period with a train of 14 pulses (4 ms, 100 Hz) were significantly less (P less than 0.01) than fibrillation thresholds determined by scanning the vulnerable period with a single 10-ms stimulus. Following beta-adrenergic blockade with propranolol, the relative increase in the fibrillation thresholds measured with trains was about seven times greater than the relative increase in the single-stimulus threshold (P less than 0.01). In a group of animals subjected to chronic cardiac denervation, fibrillation thresholds measured with trains were about three times greater than in a group of shamthoracotomized animals (P less than 0.01). Furthermore, the train fibrillation thresholds of the catecholamine-depleted hearts were not significantly different from the train thresholds of beta-blocked innervated hearts. These data, coupled with the finding that trains of stimuli produced a marked augmentation in local myocardial contractile force, suggest that locally released norepinephrine during a fibrillation-threshold determination may exert a profound influence on the level of current necessary to evoke fibrillation.