Quantitative Echocardiographic Evaluation of Mitral Endocardiosis in Dogs Using Ratio Indices

• Published in: Journal of veterinary internal medicine 2005-07, Vol.19 (4), p.542-552
• Main Authors: Brown, Donald J., Rush, John E., MacGregor, John, Ross Jr, James N., Brewer, Barbara, Rand, William M.
• Format: Article
• Language: English
• Subjects: Animals; Data interpretation; Dog Diseases - diagnostic imaging; Dogs; Heart anatomy; Heart Failure - diagnostic imaging; Heart Failure - etiology; Heart Failure - veterinary; Mitral Valve Insufficiency - complications; Mitral Valve Insufficiency - diagnostic imaging; Mitral Valve Insufficiency - veterinary; Reference values; Retrospective Studies; Ultrasonography
• ISSN: 0891-6640; 1939-1676
• DOI: 10.1111/j.1939-1676.2005.tb02725.x

This study compares M‐mode echocardiographic ratio indices (ERIs) in dogs with mitral regurgitation due to chronic valvular disease (CVD/MR) for their ability to discriminate and quantify associated echocardiographic changes. Weight‐based M‐mode ERIs were determined retrospectively for 2 groups of dogs, normal (n = 47) and CVD/MR (n = 176). The CVD/MR group was further subdivided into those with (CVD/MR B, n = 74) and without (CVD/MR A, n = 102) left‐sided congestive heart failure (LCHF). ERIs were compared descriptively (summary statistics) and also by receiver‐operator characteristic curve areas (ROCAs) for their ability to discriminate between groups. Univariate logistic regression (LR) models were used to estimate the odds ratio for each ERI as a predictor of the CVD/MR condition as well as to predict LCHF within the CVD/MR group. A novel ERI (wΔA), designed to express body size‐normalized short‐axis stroke area, was sensitive (90%) and specific (98%) to discriminate between normal and CVD/MR at a cutoff value of 1.8 standard deviations (wΔA = 2.1). Prediction of LCHF within the CVD/MR group was more problematic, but an ERI expressing left atrial size (wLA) showed 76% sensitivity and 81% specificity at a cutoff value of 5.2 standard deviations (wLA = 1.55). Ours was a descriptive study of echocardiographic patterns of pathology associated with CVD/MR and determined which ERIs are sensitive and specific for CVD/MR and for LCHF. ERIs normalize echocardiographic data for body size in dogs and are well‐suited to quantitative descriptions and analysis.