Transthoracic Echocardiographic Examination in the Rabbit Model

Summary

Here we describe, step by step, a detailed protocol for performing echocardiography in the rabbit model. We show how to correctly obtain the different echocardiographic views and imaging planes, as well as the different imaging modes available in a clinical echocardiography system routinely used in human and veterinary patients.

Abstract

Large animal models such as the rabbit are valuable for translational preclinical research. Rabbits have a similar cardiac electrophysiology compared to that of humans and that of other large animal models such as dogs and pigs. However, the rabbit model has the additional advantage of lower maintenance costs compared to other large animal models. The longitudinal evaluation of cardiac function using echocardiography, when appropriately implemented, is a useful methodology for preclinical assessment of novel therapies for heart failure with reduced ejection fraction (e.g. cardiac regeneration). The correct use of this non-invasive tool requires the implementation of a standardized examination protocol following international guidelines. Here we describe, step by step, a detailed protocol supervised by veterinary cardiologists for performing echocardiography in the rabbit model, and demonstrate how to correctly obtain the different echocardiographic views and imaging planes, as well as the different imaging modes available in a clinical echocardiography system routinely used in human and veterinary patients.

Introduction

Longitudinal evaluation of cardiac function in large animal models is a robust research methodology commonly used for the assessment of the effects of novel therapies for treating ischemic and non-ischemic cardiomyopathy. Amongst the several cardiovascular imaging techniques available for preclinical research, echocardiography has been used extensively because of its non-invasive and portable characteristics. In experienced hands, echocardiography is also a very reproducible imaging technique to study cardiac anatomy as well as systolic and diastolic function of the heart.

Large preclinical animal models such as pigs, dogs and rabbits, are ....

Protocol

The experiments described herein were approved by the Ethical Research Committee of the University of Murcia, Spain, and were performed in accordance with Directive 2010/63/EU of the European Commission. The steps described were performed under standard operating protocols that were part of the plan of work and have not been performed solely for the purpose of filming the accompanying video to this paper.

1. Preparation of the rabbit

1. Before proceeding, start by injecting a combination of ketamine (10 mg/kg) homogenized in the same syringe with medetomidine (200 µg/kg) to anaesthetize the animal, which will reduce the stress of t....

Results

Parasternal long axis view of the heart

Figure 5A shows an imaging plane of the right PSLAX view where the 4 chambers of the heart are clearly distinguished. You can identify in this view the right ventricle (RV), tricuspid valve (TV), IVS, LV, FW, as well as the mitral valve (MV). When the apex is clearly visible on the left side of the image in this view and the LV is not foreshor.......

Discussion

We have described a protocol for the echocardiographic examination of cardiac function parameters in the rabbit, representing a large preclinical model^1,2,3. The step by step methodology described herein should be considered guidance, which with a complementary study of the basic principles of echocardiography, and a basic knowledge of ultrasound imaging, will help the researcher to obtain, through practice and complementary and.......

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Bluesensor	Medicotest	13BY1062	Disposable adhesive ECG lectrodes
Domtor (Medetomidine)	Esteve	CN 570686.3	Veterinary prescription is necessary
HD11 XE Ultrasound System	Philips	10670267	Echocardiography system.
Heating Pad	Solac	CT8632
Imalgene (Ketamine)	Merial	RN 9767	Veterinary prescription is necessary
Omnifix-F 1 ml syringe	Braun	9161406V
S12-4	Philips	B01YgG	4-12 MHz phase array transducer
Ultrasound Transmision Gel (Aquasone)	Parker laboratories Inc.	N 01-08