Echocardiographic Evaluation of the Mitral Valve in Cavalier King Charles Spaniels

Abstract

This prospective cross-sectional study aimed to: (1) characterize echocardiographic features of mitral valve in MMVD affected Cavalier King Charles Spaniels (CKCS), focusing on dogs classified as American College of Veterinary Internal Medicine (ACVIM) class B1; (2) compare echocardiographic data in ACVIM B1 dogs divided on the basis of age at time of MMVD diagnosis, in order to understand if different aged subjects had different echocardiographic patterns. Length (AMVL), width (AMVW) and area (AMVA) of the anterior mitral valve leaflet, mitral valve prolapse, diameters of the mitral valve annulus in diastole (MVAd) and systole (MVAs) of 90 CKCS in different ACVIM classes, 64 of which in class B1, were measured. Valvular measurements were indexed to body weight using Wesselowski’s scaling exponents. The presence of heart murmur did not discriminate between A and B1 classes (p = 0.128). Heart enlargement was more frequent in males (r2 = 0.07, p = 0.013). Within class B1, older subjects showed significantly higher values of AMVA, AMVW, MVAd, MVAs and lower sphericity index (SI). Since many CKCS with MMVD have no murmur and their mitral valve has peculiarities, a specifically designed echocardiographic screening should be realized. In addition, different aged B1 dogs have different echocardiographic patterns that may imply different genetic and prognostic profiles.

Clinical and Echocardiographic Findings in an Aged Population of Cavalier King Charles Spaniels

“…On echocardiographic examination, MVP was a common finding in our population (88%). This result is in accordance with previous studies conducted on CKCSs [ 16 , 18 , 31 ]. Our results showed that the presence and the severity of MVP were independent of sex; on the contrary, MVP severity was significantly positively associated with age and negatively with BW.…”

“…An interesting finding was that 16% of the 56 dogs with echocardiographic evidence of MMVD and without signs of cardiac remodelling did not present murmur on cardiac auscultation. This percentage is lower than that reported in a recent publication [ 31 ], but it should be taken into account when applying breed schemes based solely on auscultation [ 36 ].…”

“…Our results showed that the prevalence of MMVD in a population of 126 CKCSs ≥ 8 years old was 100%. Despite the expected high prevalence of MMVD in our elderly CKCS population [ 13 , 14 , 15 , 16 , 18 , 19 , 31 ], 56 dogs (44.4%) were clear of echocardiographic signs of cardiac remodelling which, based on the most recent American College of Veterinary Internal Medicine (ACVIM) Consensus Statement, would be classified as stage B1 MMVD [ 4 ]. Similar findings were reported in a previous study in which 38.5% of CKCSs aged over 10 years old, with echocardiographic evidence of MMVD, did not have LA or LV dilation [ 19 ].…”

Echocardiographic mitral valve association with morphometric measurements in Cavalier King Charles Spaniels via Inverse Probability Weighting analysis

“…The aim of this study was to investigate morphometric measurements in relation with echocardiographic features of MMVD in American College of Veterinary Internal Medicine (ACVIM) class B1 CKCS [14]. This class, in fact, includes the majority of the breeding population and is very heterogeneous from clinical, morphological and echocardiographic points of view [15].…”

“…The copyright holder for this preprint (which this version posted April 15, 2021. ; https://doi.org/10.1101/2021.04. 15.439951 doi: bioRxiv preprint 4 (ACVIM) class B1 CKCS [14]. This class, in fact, includes the majority of the breeding population and is very heterogeneous from clinical, morphological and echocardiographic points of view [15].…”