Hunt G B, Ross D L
Department of Medicine, Westmead Hospital, Australia.
Circulation. 1988 Jul;78(1):221-6. doi: 10.1161/01.cir.78.1.221.
The effects of three anesthetic agents on the inducibility of ventricular tachycardia by programmed stimulation were investigated in dogs with a surgically induced left ventricular infarct. Endocardial catheter electrodes were placed at the right ventricular apex under general anesthesia at least 2 weeks after infarction, and the dogs were allowed to recover for 24 hours before undergoing programmed stimulation in the conscious state on two occasions 2 hours apart. A protocol of programmed stimulation with up to seven ventricular extrastimuli was used. In 15 animals, ventricular tachycardia was inducible on both occasions with 3.4 +/- 0.4 (mean +/- SEM; range, 1-5) extrastimuli. Two hours after baseline conscious induction, the dogs were anesthetized with either halothane, pentobarbital, or a fixed combination of fentanyl-droperidol plus nitrous oxide. Halothane prolonged the PR interval from 99 +/- 4 to 117 +/- 6 msec (p = 0.001) and the ventricular effective refractory period from 140 +/- 4 to 157 +/- 6 msec (p = 0.008). The ability to induce ventricular tachycardia was abolished in five of 10 animals (p less than 0.05). In the animals that remained inducible, the cycle length of tachycardia increased from 153 +/- 10 to 168 +/- 10 msec (p = 0.015), while the number of extrastimuli required was unaltered. Pentobarbital prolonged the PR interval from 104 +/- 6 to 124 +/- 6 msec (p = 0.004) and the QTc interval from 270 +/- 10 to 310 +/- 6 msec (p = 0.006). Ventricular tachycardia remained inducible in only six of 10 dogs (p less than 0.05) with no change in cycle length or the number of extrastimuli required. Ventricular fibrillation was inducible in an additional three dogs with a number of extrastimuli similar to that required to induce ventricular tachycardia before anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)
在患有手术诱导性左心室梗死的犬中，研究了三种麻醉剂对程序刺激诱发室性心动过速的影响。在梗死至少2周后，于全身麻醉下将心内膜导管电极置于右心室心尖处，让犬恢复24小时，然后在清醒状态下相隔2小时进行两次程序刺激。采用了最多包含七个室性期外刺激的程序刺激方案。在15只动物中，两次均能用3.4±0.4（平均值±标准误；范围1 - 5）个期外刺激诱发出室性心动过速。在基线清醒诱导后两小时，用氟烷、戊巴比妥或芬太尼 - 氟哌利多加氧化亚氮的固定组合对犬进行麻醉。氟烷使PR间期从99±4延长至117±6毫秒（p = 0.001），使心室有效不应期从140±4延长至157±6毫秒（p = 0.008）。10只动物中有5只诱发室性心动过速的能力被消除（p < 0.05）。在仍可诱发的动物中，心动过速的周期长度从153±10增加至168±10毫秒（p = 0.015），而所需期外刺激的数量未改变。戊巴比妥使PR间期从104±6延长至124±6毫秒（p = 0.004），使QTc间期从270±10延长至310±6毫秒（p = 0.006）。10只犬中只有6只仍可诱发出室性心动过速（p < 0.05），心动过速周期长度和所需期外刺激数量均无变化。另外有3只犬可诱发出心室颤动，诱发所需期外刺激的数量与麻醉前诱发出室性心动过速所需数量相似。（摘要截断于250字）
