Abstract
Objective To modify the chronic atrial fibrillation of atrial tachycardia pacing in beagles with a homemade pacemaker placed outside the body and to evaluate connective tissue growth factor and fibrosis of atrial tissue in our modified atrial tachycardia pacing beagle model.Methods Twelve adult beagles of either sex were randomly divided into an atrial tachycardia pacing group and a control group (n=6 in each group). We performed the temporary pacemaker implantation at the right atrial appendage and put the pacemaker into the pocket of dog clothing in the atrial tachycardia pacing group. After eight weeks of atrial tachycardia pacing, the electrocardiography, transthoracic echocardiography, hematoxylin-eosin staining, and Masson’s staining of the right atrial appendages were performed along with the immunohistochemistry, quantitative real-time polymerase chain reaction, and Western blot analysis of connective tissue growth factor, collagen I, and collagen III.Results In the atrial tachycardia pacing group, atrial fibrillation was induced in five beagles (83.3%); the left atrium enlarged significantly; more canines had mitral regurgitation; and the Masson’s staining, quantitative real-time polymerase chain reaction, and Western blot results demonstrated more obvious fibrosis of the left atrium.Conclusion The modified beagle model of atrial fibrillation using a right atrium pacemaker outside the body was effective, increased connective tissue growth factor and collagen I messenger ribonucleic acid overexpression, and induced atrial fibrosis.
Highlights
Atrial fibrillation (AF) is one of the most common sustained cardiac arrhythmias with a relevant effect on mortality and morbidity, especially in the elderly[1]
In the atrial tachycardia pacing group, atrial fibrillation was induced in five beagles (83.3%); the left atrium enlarged significantly; more canines had mitral regurgitation; and the Masson’s staining, quantitative real-time polymerase chain reaction, and Western blot results demonstrated more obvious fibrosis of the left atrium
The ECGs showed that all canines were in sinus rhythm and did not switch to AF with the S1S2 and burst stimulations either
Summary
Atrial fibrillation (AF) is one of the most common sustained cardiac arrhythmias with a relevant effect on mortality and morbidity, especially in the elderly[1]. Subclinical episodes of AF occur frequently in type 2 diabetic patients and have been associated with a significantly increased risk of stroke[2]. The atrial structural abnormalities included fibrosis[4], dilation, ischaemia, infiltration, and hypertrophy[5]. The chronic AF models include the atrial tachycardia pacing (ATP) model, congestive heart failure (CHF) model, sterile pericarditis model, and chronic volume overload (CVO) model[7]. Because most patients have combined permanent AF, we chose the ATP AF canine model to perform the research. We have made some modifications to the common ATP AF model in order to understand the effect of this modified model
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
