Department of Physiology and Biophysics, University of Louisville, Louisville, KY, USA.
Acad Emerg Med. 2010 Apr;17(4):436-43. doi: 10.1111/j.1553-2712.2010.00708.x.
Because of the prevalence of methamphetamine abuse worldwide, it is not uncommon for subjects in law enforcement encounters to be methamphetamine-intoxicated. Methamphetamine has been present in arrest-related death cases in which an electronic control device (ECD) was used. The primary purpose of this study was to determine the cardiac effects of an ECD in a methamphetamine intoxication model.
Sixteen anesthetized Dorset sheep (26-78 kg) received 0.0 mg/kg (control animals, n = 4), 0.5 mg/kg (n = 4), 1.0 mg/kg (n = 4), or 1.5 mg/kg (n = 4) of methamphetamine hydrochloride as a slow intravenous (IV) bolus during continuous cardiac monitoring. The animals received the following exposures in sequence from a TASER X26 ECD beginning at 30 minutes after the administration of the drug: 1) 5-second continuous exposure, 2) 15-second intermittent exposure, 3) 30-second intermittent exposure, and 4) 40-second intermittent exposure. Darts were inserted at the sternal notch and the cardiac apex, to a depth of 9 mm. Cardiac motion was determined by thoracotomy (smaller animals, < or = 32 kg) or echocardiography (larger animals, > 68 kg). Data were analyzed using descriptive statistics and chi-square tests.
Animals given methamphetamine demonstrated signs of methamphetamine toxicity with tachycardia, hypertension, and atrial and ventricular ectopy in the 30-minute period immediately after administration of the drug. Smaller animals (n = 8, < or = 32 kg, mean = 29.4 kg) had supraventricular dysrhythmias immediately after the ECD exposures. Larger animals (n = 8, > 68 kg, mean = 72.4) had only sinus tachycardia after the exposures. One of the smaller animals had frequent episodes of ventricular ectopy after two exposures, including runs of delayed onset, nonsustained six- to eight-beat unifocal and multifocal ventricular tachycardia that spontaneously resolved. This animal had significant ectopy prior to the exposures as well. Thoracotomy performed on three smaller animals demonstrated cardiac capture during ECD exposure consistent with previous animal studies. In the larger animals, none of the methamphetamine-intoxicated animals demonstrated cardiac capture. Two control sheep showed evidence of capture similar to the smaller animals. No ventricular fibrillation occurred after the exposure in any animal.
In smaller animals (32 kg or less), ECD exposure exacerbated atrial and ventricular irritability induced by methamphetamine intoxication, but this effect was not seen in larger, adult-sized animals. There were no episodes of ventricular fibrillation after exposure associated with ECD exposure in methamphetamine-intoxicated sheep.
由于全世界范围内冰毒滥用的普遍性，在执法过程中遇到的吸毒者中毒并不罕见。在涉及使用电子控制装置（ECD）的逮捕相关死亡案件中，已经发现了冰毒的存在。本研究的主要目的是确定 ECD 在冰毒中毒模型中的心脏效应。
16 只麻醉的 Dorset 绵羊（26-78 公斤）接受 0.0mg/kg（对照动物，n=4）、0.5mg/kg（n=4）、1.0mg/kg（n=4）或 1.5mg/kg（n=4）的盐酸甲基苯丙胺作为缓慢静脉（IV）推注，在连续心脏监测期间。动物在给药后 30 分钟内从 TASER X26 ECD 开始接受以下暴露：1）5 秒连续暴露，2）15 秒间歇暴露，3）30 秒间歇暴露，4）40 秒间歇暴露。飞镖插入胸骨切迹和心尖，深度为 9 毫米。通过开胸术（较小的动物，<或=32 公斤）或超声心动图（较大的动物，>68 公斤）确定心脏运动。使用描述性统计和卡方检验分析数据。
给予甲基苯丙胺的动物在药物给药后 30 分钟内立即出现甲基苯丙胺毒性的迹象，表现为心动过速、高血压、房性和室性心律失常。较小的动物（n=8，<或=32 公斤，平均=29.4 公斤）在 ECD 暴露后立即出现室上性心律失常。较大的动物（n=8，>68 公斤，平均=72.4）在暴露后仅出现窦性心动过速。一只较小的动物在两次暴露后出现频繁的室性异位搏动，包括延迟发作、非持续六至八拍单发和多灶性室性心动过速，自发缓解。这只动物在暴露前也有明显的异位。在三只较小的动物中进行的开胸术显示 ECD 暴露期间存在心脏捕获，这与以前的动物研究一致。在较大的动物中，没有一只甲基苯丙胺中毒的动物表现出心脏捕获。两只对照羊显示出与较小动物相似的捕获证据。在任何动物中，暴露后均未发生心室颤动。
在较小的动物（32 公斤或以下）中，ECD 暴露加剧了甲基苯丙胺中毒引起的心房和心室易激性，但在较大的成年动物中未观察到这种作用。在甲基苯丙胺中毒的绵羊中，与 ECD 暴露相关的暴露后没有发生心室颤动的事件。
