Vertebral left atrial size (VLAS) is a repeatable radiographic measurement for quantifying left atrial size and does not appear to be affected by bodyweight, age or sex
Journal citation

Vezzosi, T., Puccinelli, C., Tognetti, R.,et al (2020)
Radiographic vertebral left atrial size: A reference interval study in healthy adult dogs
Veterinary Radiology and Ultrasound; 61 (5) 507-511
Abstract

Published September/October 2020

Type of study
  • Retrospective study
  • n = 80 dogs
Key points
  • 80 healthy dogs with normal left atrial size confirmed with echocardiographic La:Ao ratio of <1.6
  • The median value of VLAS was 9 (range 1.3-2.2)
  • No effect of body weight, sex or age was found
  • Median Vertebral Heart Score (VHS) was 10 (range 9.2-11)

Limitations

  • Although the study included various breeds, no brachycephalics were included which typically have a barrel shaped thoracic conformation so the results may not be applicable to these breeds
  • All radiographic measurements were performed by operators working in radiology and it is unknown if this is transferable to non-radiology colleagues
Conclusions
  • VLAS is a repeatable radiographic measurement for quantifying left atrial size and confirms a previously proposed cut off for LA atrial enlargement of ≥ 2.3