Premium
Thyroid Hormone Predisposed Rabbits to Atrial Arrhythmia: A Possible New Model of Atrial Arrhythmias
Author(s) -
Yu Zhui,
Huang Congxin,
Wang Songyang,
Wang Teng
Publication year - 2007
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.21.5.a130-d
Subject(s) - atrial fibrillation , medicine , propranolol , tachycardia , atrial flutter , atrial tachycardia , effective refractory period , atrium (architecture) , saline , hormone , endocrinology , cardiology , refractory period , ventricle , anesthesia , catheter ablation
The aim is to explore a new method of reproducing in vivo model of atrial arrhythmias. Our study was divided into two parts, in part one 18 rabbits were randomized into Control group, Thyroxine group and Propranolol group. Rabbits were injected intraperitoneally with 1mg/kg·d L‐thyroxine (L‐T 4 ) solution for 14 days in Thyroxine group. Besides L‐T 4 treatment, 4mg/kg·d propranolol was given since the eighth day in Propranolol group. In Control group, the same volume saline were injected. In part two, 12 rabbits were divided into Control group and Thyroxine group, with the same treatment as part one. On the 15th day, electrophysiological experiment in part one showed that monophasic action potential and effective refractory period in Thyroxine group were significantly shorter than those in Control and Propranolol group. The incidence of atrial arrhythmias(including atrial tachycardia, atrial flutter and atrial fibrillation) induced by electric stimulation in three groups was 1/6(Control group), 7/6(Thyroxine group) and 4/6(Propranolol group) respectively. In part two, the expression of L‐type calcium channel mRNA of atrium and ventricle in Thyroxine group were significantly higher than those in Control group. We conclude that L‐T 4 may predispose the rabbits to atrial arrhythmias and the mechanisms of atrial fibrillation(AF) in hyperthyroidism were not the same as those of other types of AF.