Fukushima Ryuji, Tanaka Ryou, Matsumoto Hirotaka, Machida Noboru, Hirose Hisashi, Yamane Yoshihisa, Koyama Hidekazu
Laboratory of Veterinary Surgery, Tokyo University of Agriculture and Technology, Tokyo, Japan.
J Vet Med Sci. 2010 Jul;72(7):833-8. doi: 10.1292/jvms.09-0358. Epub 2010 Feb 23.
It is required not to increase the ventricular rate and to preserve the ventricular systolic function in treating supraventricular tachyarrhythmia (SVTA). The objective of this study is to investigate whether or not Efonidipine hydrochloride (EH), a T and L dual type Ca(2+) channel blocker, suppresses the increasing ventricular rate without reducing the ventricular systolic function using canine SVTA models by rapid atrial pacing (RAP) method. Clinically healthy fourteen beagles were used. The 14 dogs were randomly assigned to the EH-administered group (EH group, n=7) and non-EH-administered group (control group, n=7). The EH group was orally-administered EH at 5 mg/kg SID during RAP. On the other hand, the control group was applied RAP without oral administration of EH. Duration of RAP was for 3 weeks for both groups. The ventricular rate for the EH group was significantly lower than that for the control group. The left ventricular- fractional shortening for the control group declined significantly compared to baseline. Those for the EH group did not show any changes over time and were significantly higher than the control group. The ratio between pre-ejection period and ejection for the EH group were significantly lower than those of the control group. In conclusion, the study demonstrated that EH suppresses the increasing ventricular rate without reducing the ventricular systolic function in canine SVTA model. Therefore, EH is expected to become a new treatment for canine SVTA.
在治疗室上性快速心律失常（SVTA）时，要求不增加心室率并保留心室收缩功能。本研究的目的是通过快速心房起搏（RAP）方法，使用犬类SVTA模型，研究T型和L型双钙通道阻滞剂盐酸依福地平（EH）是否能在不降低心室收缩功能的情况下抑制心室率增加。使用了14只临床健康的比格犬。将这14只狗随机分为EH给药组（EH组，n = 7）和非EH给药组（对照组，n = 7）。在RAP期间，EH组以5 mg/kg的剂量口服EH，每日一次。另一方面，对照组在不口服EH的情况下进行RAP。两组的RAP持续时间均为3周。EH组的心室率显著低于对照组。与基线相比，对照组的左心室缩短分数显著下降。EH组的左心室缩短分数随时间没有变化，且显著高于对照组。EH组的射血前期与射血期之比显著低于对照组。总之，该研究表明，在犬类SVTA模型中，EH能在不降低心室收缩功能的情况下抑制心室率增加。因此，EH有望成为犬类SVTA的一种新治疗方法。
