Open Access

Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart

  • Authors:
    • Dan-Ning Wang
    • Lei Wang
    • Ying Huang
    • Li Hua
    • Hai-Ming Cui
    • Peng-Fei Chen
    • Xin Liang
    • Jia-You Zhang
    • De-Ning Liao
  • View Affiliations

  • Published online on: September 4, 2018     https://doi.org/10.3892/etm.2018.6695
  • Pages: 4114-4118
  • Copyright: © Wang et al. This is an open access article distributed under the terms of Creative Commons Attribution License.

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Abstract

This study observed the effects of early intravenous low-doses of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction (MI) dogs. Thirty two mongrel dogs with the first diagonal branch of the left anterior descending coronary artery ligated were randomly divided into three groups: The low-dose group was given metoprolol 0.6 mg/kg immediately by intravenous injection (n=12); the target-dose group was given metoprolol 1.6 mg/kg (n=12), and the control group was injected with normal saline at the same dose of the target-dose group (n=8). Norepinephrine (NE) and epinephrine (E) levels in the coronary sinus (CS) blood as well as the ventricular effective refractory period (ERP) were all measured during the experiments. We found that NE and E concentrations in the three groups were all increased compared with the previous measurement before ligation. ERP values after MI were significantly decreased in all three groups compared with the first measurements. The three groups all exhibited uneven shortness of ERP among different regions, with significant shortness in infarcted area. Furthermore, there was no difference between the low and target-dose of metoprolol in the reduction of regional ERP, and the same effect was also observed in induced arrhythmias. In conclusion, a lower dose of metoprolol performed similarly as target-dose in reducing the catecholamine concentrations in dogs with MI. Our study demonstrated that a lower dose of metoprolol may be reasonable compared with the target-dose in β-blocker therapy due to similar effect and lower toxicity.
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November-2018
Volume 16 Issue 5

Print ISSN: 1792-0981
Online ISSN:1792-1015

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Spandidos Publications style
Wang D, Wang L, Huang Y, Hua L, Cui H, Chen P, Liang X, Zhang J and Liao D: Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart. Exp Ther Med 16: 4114-4118, 2018
APA
Wang, D., Wang, L., Huang, Y., Hua, L., Cui, H., Chen, P. ... Liao, D. (2018). Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart. Experimental and Therapeutic Medicine, 16, 4114-4118. https://doi.org/10.3892/etm.2018.6695
MLA
Wang, D., Wang, L., Huang, Y., Hua, L., Cui, H., Chen, P., Liang, X., Zhang, J., Liao, D."Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart". Experimental and Therapeutic Medicine 16.5 (2018): 4114-4118.
Chicago
Wang, D., Wang, L., Huang, Y., Hua, L., Cui, H., Chen, P., Liang, X., Zhang, J., Liao, D."Effects of early intravenous low-dose of metoprolol on cardiac sympathetic activities and electrophysiological properties in myocardial infarction heart". Experimental and Therapeutic Medicine 16, no. 5 (2018): 4114-4118. https://doi.org/10.3892/etm.2018.6695