Fetal echocardiography in B and M modes for to standardize morphological and functional cardiovascular variables of canine fetuses in the final third of gestation: fetal echocardiographic measurements

Abstract

Fetal echocardiography allows early diagnosis of cardiovascular changes. However, few studies have described physiological values ​​that allow a quantitative evaluation for this test in dogs. The objective was to describe the presumed physiological values ​​of echocardiographic variables obtained in B and M modes, and cardiac function, by canine fetal echocardiography in the last trimester of pregnancy. Twenty fetuses were submitted to fetal echocardiography. The variables that showed a statistically significant correlation coefficient in relation to fetal age were the diameter of the aorta and the thickness of the interventricular septum in systole and in diastole. The morphological evaluation allowed the observation and determination that the heart occupied an average of one third of the thorax, most of it located in the left hemithorax and with the apex turned to the left. By identifying the spine, the anterior wall of the chest was observed opposite to it, represented by the sternum.  The right ventricle was found just below, separated from the right atrium by the tricuspid valve. Both ventricles showed similar size, thickness and contractility. The measurement of ejection fractions and shortening allowed the determination of the left ventricular systolic function. This study determined physiological values ​​for the main echocardiographic variables obtained in B and M modes for the investigated group.