Vet World   Vol.13   November-2020  Article-20

Left ventricular systolic function in dogs with pulmonic stenosis

Background and Aim: Pulmonic stenosis (PS) is the most common congenital heart disease in dogs. This condition causes right ventricle (RV) overload and disrupts overall systolic function. The aim of this study was to examine the alterations of cardiac electrical activity and mechanical function in dogs with PS compared to normal healthy dogs.

Materials and Methods: The ventricular systolic function of dogs with PS was studied. Dogs were divided into two groups, PS (n=13) and control (CONT) (n=12). Measurements of blood pressure, electrocardiography (ECG), and echocardiography were performed.

Results: PS dogs had exercise intolerance, with six experiencing syncope. ECG of PS dogs showed higher amplitudes of P, S, and T waves (p<0.01), and a lower R:S ratio (p<0.001) with longer QRS duration (p<0.001) compared to CONT dogs. Echocardiography demonstrated that the pulmonic flow velocity and pressure gradient (PG) between the RV and the pulmonary artery of PS dogs were significantly higher than CONT dogs (p<0.001). The RV free wall thickness to the left ventricular posterior wall thickness ratio and the right atrium to the left atrium diameter ratio was higher (p<0.001), while interventricular septum (IVS) was thicker (p<0.01) in PS dogs compared with CONT dogs (p<0.001). The systolic function in PS dogs showed higher pulmonic valve velocity time integral (PVVTI) value (p<0.001) and longer pulmonic valve ejection time (ET) (p<0.05) than CONT dogs. However, aortic valve VTI (AVVTI) value and aortic valve ET were not significantly different between the groups, although fractional shortening in PS dogs was higher. In PS dogs, PG showed a significant positive correlation with PVVTI:AVVTI ratio (p<0.05).

Conclusion: PS had prolonged pulmonic valve opening. The thickening of the RV wall and IVS can cause a detrimental reduction of the left ventricular preload in PS dogs. Keywords: dogs, pulmonic stenosis, ventricular function.

Keywords: dogs, pulmonic stenosis, ventricular function.

How to cite this article: Trikhun P, Surachetpong SD, Sutayatram S, Buranakarl C (2020) Left ventricular systolic functions in dogs with pulmonic stenosis, Veterinary World, 13(11): 2436-2442.

Received: 28-08-2020  Accepted: 05-10-2020     Published online: 14-11-2020

Corresponding author: Chollada Buranakarl   E-mail: bchollad@chula.ac.th

DOI: 10.14202/vetworld.2020.2436-2442

Copyright: Trikhun, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.