Radiographic quantification of left atrial size in dogs with myxomatous mitral valve disease

Abstract

Background: In the absence of echocardiography, identification of cardiomegaly via thoracic radiography is a necessary criterion for classification of disease severity in dogs with myxomatous mitral valve disease (MMVD). Objective: Modified-vertebral left atrial size (M-VLAS) facilitates objective radiographic assessment of the left atrium (LA) in 2 dimensions and identifies LA enlargement more accurately than existing methods. Animals: Sixty-four dogs with various stages of MMVD and 6 control healthy dogs. Methods: Retrospective case-control study. Medical records were searched for dogs with varying severity of MMVD. Modified-vertebral left atrial size, vertebral left atrial size (VLAS), vertebral heart size (VHS), and radiographic left atrial dimension (RLAD) were measured from thoracic radiographs and compared with echocardiographically derived measurements.

Breed‐specific vertebral heart score, vertebral left atrial size, and radiographic left atrial dimension in Cavalier King Charles Spaniels: Reference interval study

“…18 The VLAS found in our study population is lower than the values proposed by Malcolm et al and more similar to those reported by Puccinelli et al 7,21 The same difference from data reported by literature can be observed for M-VLAS and RLAD. 8,9 It is interesting to report that the The main limitation for the current study was the small sample size.…”

“…A correlation analysis between VHS, VLAS, M‐VLAS, RLAD, and TD to TW ratio was performed to determine whether chest conformation was responsible for variation in these radiographic parameters. To compare obtained VHS, VLAS, M‐VLAS, and RLAD measurements, the values from Malcolm's study expressed as median and interquartile range were converted to mean and standard deviation (2.07 ± 0.25 vertebrae); 7 the same was for M‐VLAS (2.6 ± 0.3 vertebrae) and RLAD (1.97 ± 0.57 vertebrae) 8,9,34 . A one sample t ‐test was then used to test whether the VHS, VLAS, M‐VLAS, and RLAD in our population of CKCS differed from the mean reference values proposed by literature 6–9,32 .…”

“…[10][11][12][13][14][15][16][17][18][19][20] Only normal values of VHS in CKCS have been investigated and are reported to be higher than not-breed-specific reference ranges (respectively 10.6 ± 0.5 vs 9.7 ± 0.5). 3,10 The VLAS, M-VLAS, and RLAD have recently been proposed as new radiographic methods for quantifying left atrial size in dogs [7][8][9] ; however, no published studies have evaluated VLAS, M-VLAS, and RLAD in different breeds. A recent study reported values for VLAS in Chihuahuas.…”

“…In this breed, thoracic radiographs are frequently used to screen for evidence of left‐sided cardiomegaly secondary to MMVD 3,4 . Published radiographic measures of heart size include vertebral heart size (VHS), vertebral left atrial size (VLAS), its modified version (M‐VLAS), and radiographic left atrial dimension (RLAD) 3,5–9 . The VHS is influenced by different morphotypes and several studies have described breed‐specific reference range 10–20 .…”

“…The thoracic radiographic studies were obtained with a digital system (RX D-VET G35i, FUJIFILM Italia S.P.A., Milano, Italia) and radiographic exposure factors for each dog were based on patient body size.A dedicated image analysis workstation (iMac Retina 5K, 27-inch, 2014 with OsiriX© MD v. 8.0.2, Pixmeo SARL, Swizerland) was used for all radiographic measurements. The radiographic evaluations of VHS, VLAS, M-VLAS, and RLAD were performed using digital calipers for both RL and LL radiographic views [6][7][8][9]32. Each length was expressed in F I G U R E 1 Right lateral thoracic radiographic image of a CKCS demonstrating the radiographic measurements of vertebral heart size (VHS) performed in this study (kVp 75, mAs 2.5).…”