TDK conference 2020

Our knowledge between the correlation of the heart and body construction in different dogs is limited. However, this data might provide useful information about the diagnostics and pathogenesis of some diseases.

The goal of my study is to examine the relationship between the morphometrics of the heart the shape of the thorax and the body frame using Computed Tomography (CT) imaging.

According to our hypothesis, the anatomical heart axis, the thorax angle and the proportional volumes of the ventricles and papillary muscles, vary between dogs of different thorax conformation.

15 dogs were involved in this study. The animals showed no clinical signs for cardiac and thoracic diseases and anomalies. The average bodyweight was 11.95 kgs, while the smallest dog weighed 7 kgs and the heaviest 17.3 kgs.

The CT scans were performed in the Somogy County Kaposi Mór Teaching Hospital, Dr. Baka József Diagnostical and Oncoradiological Centre in cooperation with the specialists of Medicopus Nonprofit Ltd. using a Siemens Definition Flash Dual (Siemens AG, Erlangen, Germany) equipment with an ECG-triggered heart examination protocol.

The scans were reconstructed with the 3D Slicer, 4.10.2. We measured the angle of the thorax (angle between the axis of the vertebral column and the axis of the sternum), length of the thoracic cavity’s entrance, width of the ribs at its widest point (#1;#6;#8;#11.), depth of the thorax and the gross and net length of the sternum. Additionally, we measured the volumes of the left and right ventricles of the heart, the volumes of the aorta, the volumes of the papillary muscles in the left ventricle and the angle of the heart axis. Following the corresponding studies we determined the type of the thorax using the ratio between the maximum depth of the thorax and the distance of the 8th ribs and we divided them into groups based on the shape of the thorax.

According to our results, as the chest depth increases, the extent of contraction of the m. papillaris subatrialis decreases (p=0.0132) and that of the m. papillaris subauricularis increases (p=0.0378). Between the groups with different thorax types we found significant difference between the volume of the right ventricle using ANOVA test (p = 0.0046).

The future goal of our study is to examine the relationship between thorax conformation and the heart anatomy in dogs weighing 20-40 kilos.