Intraoperative bradycardia is not an uncommon complication in anaesthetised horses and it has been recommended that severe bradycardia (defined as heart rate (HR) <25 beats/min) during general anaesthesia, when associated with hypotension (mean arterial pressure (MAP) <70 mmHg) and other signs of inadequate tissue perfusion, should be treated with anticholinergics. Muscarinic antagonists, such as atropine and glycopyrrolate, cause positive chronotropism and dromotropism (improved atrioventricular conduction) by competitively blocking the effects of acetylcholine at muscarinic receptors in the heart. However, in horses, prolonged intestinal hypomotility and colic have been associated with the use of atropine and glycopyrrolate which has led to the investigation of the use of hyoscine N‐butylbromide (hyoscine NBB) to treat alpha 2 agonist‐induced bradycardia in horses. This report describes the successful use of hyoscine NBB to treat symptomatic intraoperative bradycardia in three isoflurane‐anaesthetised horses.

中文翻译：

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在三匹马的异氟烷麻醉期间，使用盐酸正丁基溴化物治疗术中心动过缓

术中心动过缓并不是麻醉马的常见并发症，建议在全麻期间与低血压（平均动脉压（MAP）<70 mmHg）相关的严重心动过缓（定义为心率（HR）<25次/分钟） ）和其他组织灌注不足的迹象，应用抗胆碱药治疗。毒蕈碱拮抗剂（例如阿托品和格隆溴铵）通过竞争性阻断乙酰胆碱对心脏毒蕈碱受体的作用，引起正性变年性和同营养性（改善房室传导）。但是，在马匹中 长期肠蠕动和绞痛与阿托品和格隆溴铵的使用有关，这导致人们研究了使用hy碱N-丁基溴化物（hy碱NBB）治疗α2激动剂引起的马匹心动过缓。本报告描述了使用Hyscine NBB成功治疗3例异氟烷麻醉的马有症状的术中心动过缓的情况。