Prevalence and characteristics of ventricular septal defects in a non‐racehorse equine population (2008‐2019)

Abstract

Background: Ventricular septal defects (VSDs) are the most common congenital cardiac defect in horses.Objectives: To identify prevalence, age, breed, and sex distribution of VSD and to describe associated clinical and ultrasonographic findings.Animals: Hospital-based population of 21 136 horses presented to the equine internal medicine department.Methods: Medical records over a 12-year period were reviewed for VSD confirmed by ultrasonography. Age, breed, sex, sport discipline, murmur, clinical signs, outcome, VSD type, VSD size, shunt velocity, cardiac dimensions, concomitant cardiac anomalies, and valvular regurgitations were recorded.Results: From 1894 horses that underwent echocardiography, 54 had a VSD: 42 as an isolated lesion and 12 as part of complex congenital heart disease (CHD). Median age was 5 years (range, 0-26) and 1 year (range, 0-8), respectively. Warmbloods and males were overrepresented. In the isolated VSD group, only 15% had associated clinical signs and most horses had a perimembranous VSD (pmVSD; 36/42). Horses with a pmVSD and clinical signs showed a significantly lower maximal shunt velocity (3.77 vs 5.20 m/s; P < .001), higher VSD/Aortic root (Ao) diameter (0.52 vs 0.38; P = .05), higher left atrium/Ao diameter (1.94 vs 1.22; P < .001), and higher pulmonary artery/Ao diameter (1.15 vs 0.88; P = .005) compared to horses without clinical signs. All horses with complex CHD had clinical signs and abnormal cardiac dimensions. Conclusion and ClinicalImportance: Most isolated VSD were diagnosed only at a later age and were not associated with clinical signs. Horses with complex CHD were more likely to have or develop clinical signs at younger age.

Echocardiographic Features of the Ductus Arteriosus and the Foramen Ovale in a Hospital-Based Population of Neonatal Foals

“…In equids, several isolated and complex congenital cardiac defects have been reported. These are usually diagnosed after a cardiac murmur has been detected [ 13 , 17 ]. However, loud cardiac murmurs in foals shortly after birth in the absence of signs of cardiovascular compromise can be physiological findings.…”

Congenital heart defects in Arabian horses and the prospects of genetic testing: A review

“…1,25 VSDs can occur either as isolated defects or as a component of complex cases, with the prevalence of concomitant defects within VSD cases ranging from 22% to as high as 60%; however, this may be an overrepresentation as the reported study populations are either from hospitals or necropsies that are more likely to include defects of greater severity. 7,8,26 Nevertheless, the presence of other defects should be excluded in diagnosis, with additional defects often producing more severe clinical signs and a worse prognosis than isolated VSD cases. 2,4,7,10,17 A VSD occurs in cases of inadequate convergence and fusion of the primitive ventricular septum, the atrioventricular cushions and the conal ridges.…”

“…1 VSDs in horses can be classified as three main phenotypes based on their location: perimembranous, infundibular or muscular. 10,25,26 The most common type is the perimembranous or paramembranous VSD, located in the fibrous area of the membranous septum below the septal leaflet of the tricuspid valve and the junction of the right and non-coronary cusps of the aortic valve. 10,25,26 Infundibular, subarterial, doubly committed or subpulmonic VSDs are located in the fibrous continuity below the pulmonary and aortic valve leaflets.…”

“…10,25,26 The most common type is the perimembranous or paramembranous VSD, located in the fibrous area of the membranous septum below the septal leaflet of the tricuspid valve and the junction of the right and non-coronary cusps of the aortic valve. 10,25,26 Infundibular, subarterial, doubly committed or subpulmonic VSDs are located in the fibrous continuity below the pulmonary and aortic valve leaflets. 10,25,26 Muscular VSDs can be located in any muscular part of the interventricular septum, and are fully surrounded by muscular tissue.…”

A retrospective study of congenital cardiac malformations in 29 goats

“…VSD was the most common single and combined cardiac malformation in our study, as reported in other domestic species. 3,7 VSDs typically caused right-sided dilation; identification of the defect is reasonably straightforward based on the identification of a hole that connects the 2 ventricles. In our case series, a right-to-left shunt caused by significant pulmonary hypertension was not identified in any of the patients.…”