Fazekas T, Scherlag B J, Mabo P, Patterson E, Lazzara R
First Department of Medicine, Szent-Györgyi University Medical School, Szeged, Hungary.
Am Heart J. 1994 Feb;127(2):345-52. doi: 10.1016/0002-8703(94)90123-6.
The authors studied the effects of lidocaine in 18 consecutive dogs with myocardial infarction 1 to 4 days after two-stage left anterior descending coronary artery ligation. Electrophysiologic testing was performed in anesthetized dogs after infarction with single-, double-, or triple-programmed extrastimuli or rapid bursts (3 beats at 240 to 420 beats/min) delivered to the right ventricular outflow tract. Inducibility of sustained monomorphic ventricular tachycardia after an intravenous bolus of lidocaine (3 to 6 mg/kg) was compared in the same animal to the premedicated state. In the control state, sustained monomorphic ventricular tachycardia was inducible in 6 of 18 dogs. After administration of lidocaine, electrically induced sustained monomorphic ventricular tachycardia was initiated in an additional nine dogs (which were previously noninducible; after lidocaine administration vs control p < 0.02). The antiarrhythmic agent induced further rate-dependent slowing of conduction in the periinfarction subepicardium, which at a critical value of rate and amount of conduction delay resulted in sustained reentrant monomorphic tachycardia. These results show that lidocaine has marked proarrhythmic action in this canine model of myocardial infarction, probably because of its depressant effect on injured cardiac tissue.
作者对18只在冠状动脉左前降支分两阶段结扎后1至4天发生心肌梗死的犬进行了利多卡因作用的研究。在梗死的麻醉犬中，通过向右心室流出道发放单、双或三联程控期外刺激或快速猝发刺激（240至420次/分钟，3次搏动）进行电生理测试。将同一只动物静脉推注利多卡因（3至6毫克/千克）后持续性单形性室性心动过速的可诱导性与用药前状态进行比较。在对照状态下，18只犬中有6只可诱发出持续性单形性室性心动过速。给予利多卡因后，另外9只犬（之前不可诱导；利多卡因给药后与对照相比，p < 0.02）诱发出电诱导的持续性单形性室性心动过速。该抗心律失常药物导致梗死周围心外膜下传导进一步出现频率依赖性减慢，在传导延迟的临界频率和程度时导致持续性折返性单形性心动过速。这些结果表明，在这种犬心肌梗死模型中，利多卡因具有明显的促心律失常作用，可能是因为其对受损心脏组织的抑制作用。
