MORPHOMETRIC ASSESSMENT OF CANINE HEART WITHOUT MACROSCOPICALLY VISIBLE CHANGES CAUSED BY CARDIAC DISEASE

Layla Lívia Queiroz,Léa Resende Moura,Veridiana Maria Brianezi Dignani Moura

doi:10.1590/1809-6891v19e-43748

Layla Lívia Queiroz, Léa Resende Moura + Show 1 more

Open Access

https://doi.org/10.1590/1809-6891v19e-43748

Copy DOI

Abstract

Abstract The purpose of this study was to collect data on the cardiac morphometry of thirty adult male and female dogs without macroscopic changes indicative of heart disease, regardless of animal's body weight and score. The dogs were weighed, grouped according to their body weight, and necropsied for a macroscopic evaluation of their cardiac measurements. The data obtained were included in a database. The following cardiac measures were evaluated: vertical and horizontal axes, weight, volume, thickness of the right and left atria and ventricles, and horizontal and vertical axes of the atrial and ventricular chambers. The heart weight was found to represent 0.6 to 1.1% of the animal's body weight. No differences were found in cardiac size and weight as a function of sex. The ratio between the vertical and horizontal cardiac axes was 1.11. The left ventricle was found to be 1.6 to threefold thicker than the right ventricle. The results were considered standard for dogs and can be used for macroscopic evaluations of cardiac hypertrophy or dilation.

Highlights

The distinct layer of cardiac muscle, called the myocardium, consists of muscle cells, which are arranged in overlapping spiral patterns[1]
A positive correlation was found between the weight of the dogs and all the cardiac measures evaluated, except for the thickness of the right and left atria, which showed either a negative correlation or no correlation with the weight of the animals
This study provides objective information about the morphometry of the canine heart, indicating that the normal heart represents a percentage of body weight

Summary

Introduction

The distinct layer of cardiac muscle, called the myocardium, consists of muscle cells (cardiomyocytes), which are arranged in overlapping spiral patterns[1]. The thickness of the myocardium is determined by the pressure in each chamber. While the atria are thin, the ventricles are thick. Dogs’ hearts differ in shape and position from those of other domestic species[3], presenting an ovoid aspect with a blunt and rounded apex[4]. The absolute weight of the heart of a medium size dog is 40 to 600 g, corresponding to 0.9 to 2.2% of its body weight. The heart weight of obese and sedentary dogs may represent only about 0.5% of their body weight[3]

Objectives

Methods

Results

Discussion

Conclusion