Abstract：
Pimobendan is not currently approved for use in cats, although its usefulness in feline hypertrophic cardiomyopathy has been suggested. Reports indicate an increase in arrhythmic events following oral administration to healthy cats. Given the greater potency of intravenous administration compared to oral intake, it is conceivable that the incidence of arrhythmias may be increased following pimobendan injection. Therefore, this study aimed to investigate the proarrhythmic effects of pimobendan injection in cats. Five clinically healthy cats underwent physical examination, echocardiography, blood pressure measurements, and 24-hour Holter electrocardiography immediately before and after receiving pimobendan as an intravenous bolus dose of 0.15 mg/kg twice daily for 3 days. Additionally, a 24-hour Holter electrocardiography recording was conducted on the third day of pimobendan or placebo IV administration to assess heart rate, arrhythmias, and heart rate variability. Following pimobendan administration, there was a significant increase in total 24-hour heart rate. Echocardiography revealed a significant increase in mitral valve annulus systolic velocity (S\') on the ventricular septal wall side, indicative of enhanced contractility. Only one cat exhibited paroxysmal ventricular tachycardia and an increase in the frequency of arrhythmic events. Conversely, in the remaining cats, a decreasing trend in the number of arrhythmias was observed. These findings indicate that intravenous administration of pimobendan may not be implicated in the onset of arrhythmias. Nevertheless, further research is warranted to explore the effects of intravenous pimobendan administration in cats with myocardial disease.
摘要：
Pimobendan目前尚未被批准用于猫，尽管已提出其在猫科动物肥厚型心肌病中的有用性。报告表明，口服健康猫后，心律失常事件增加。与口服相比，静脉内给药的效力更大，可以想象，注射匹莫苯后心律失常的发生率可能会增加。因此,本研究旨在探讨匹莫苯注射液对猫的致心律失常作用。五只临床健康的猫接受了体检，超声心动图,血压测量,和24小时动态心电图之前和之后立即接受匹莫苯作为每日两次0.15mg/kg的静脉推注剂量持续3天。此外,在匹莫苯或安慰剂IV给药的第三天进行24小时动态心电图记录以评估心率,心律失常,和心率变异性。匹莫苯丹给药后,24小时总心率显著增加.超声心动图显示室间隔壁侧二尖瓣环收缩期速度（S'）显著增加，表明收缩力增强。只有一只猫表现出阵发性室性心动过速和心律失常事件的频率增加。相反，剩下的猫，观察到心律失常数量呈下降趋势.这些发现表明，静脉内给予匹莫苯可能与心律失常的发作无关。然而，需要进一步的研究来探索静脉注射匹莫苯对患有心肌疾病的猫的影响。
