Visual (eyeball) estimation by observers with varying echocardiographic experience reliably identifies severe but not moderate decreases of the fractional shortening in dogs.

Abstract

Objective: To assess the ability to visually estimate the fractional shortening in dogs and the impact of experience on those assessments.

Methods: Right parasternal short- and long-axis cine loops from 25 dogs with varying fractional shortening (6.9% to 61.2%) were distributed online to observers with different levels of training in anesthesiology or cardiology and different experience (advanced, intermediate, beginner, or none) interpreting echocardiography. Observers were asked to estimate the fractional shortening and assign 1 of 5 categories: hyperdynamic (> 45%), normal (25% to 45%), mildly decreased (20% to 24%), moderately decreased (15% to 19%), or severely decreased (< 15%). The answers for all cases combined were graded as correct/incorrect based on each of the 5 fractional shortening categories and compared between participants of each level experience. In addition, answers were reanalyzed using 2 categories for fractional shortening, ≥ 20% and < 20%, to test the identification of clinically important decreased function.

Results: Answers from 240 participants were received. The overall rate of correct answers averaged between 45% and 47% for all levels of experience. This improved from 79% to 83% across all levels of experience when a 2-category scale was used. Participants with advanced experience performed slightly better. The success rate for identifying fractional shortening < 20% when the dogs had moderate and severe decreases was 50% to 54% and 92% to 96%, respectively.

Conclusions: Visual estimations of the fractional shortening can be used reliably to identify cases of severe but not moderately decreased function.

Clinical relevance: A basic echocardiographic exam may identify dogs with severely decreased fractional shortening. Measurements are required to distinguish those with moderate function.