Evaluation of Subjective Assessment of Right Heart Size and Function Using Standard 2D-Echocardiographic Recordings in Horses With and Without Pulmonary Hypertension.
Authors: van Spijk Julia N, Junge Hannah K, Eberhardt Christina, Wolf Natalie, Vogt Debora, Zscherpe Paula, Herger Elena, Straub Manon, Schwarzwald Colin C
Journal: Journal of veterinary internal medicine
Summary
# Editorial Summary Subjective echocardiographic assessment of right heart size and function remains a cornerstone of equine cardiology, yet its reliability for detecting pulmonary hypertension has not been rigorously evaluated until now. Researchers recruited 90 horses—30 healthy controls and 60 with either documented or absent pulmonary hypertension by Doppler criteria—and had them assessed by nine observers (four experienced, five inexperienced) using standard two-dimensional echocardiographic recordings, with observers grading right heart size, right heart function, pulmonary artery dimensions and distensibility, and presence of pulmonary hypertension on a four-point scale. Inter-rater agreement was disappointingly low overall (61% perfect agreement; kappa 0.21), though experienced observers performed substantially better (77% agreement; kappa 0.34) than inexperienced ones (52% agreement; kappa 0.18), and intra-rater reliability varied markedly between individuals (experienced: kappa 0.35–0.76 with >80% repeat agreement; inexperienced: kappa 0.33–0.54 with <80% agreement). Abnormal right heart changes were indeed more prevalent in horses with pulmonary hypertension, conferring high specificity but critically low sensitivity for disease detection. These findings underscore that normal-appearing right heart anatomy on subjective assessment cannot exclude pulmonary hypertension, whilst characteristic changes do reasonably suggest its presence—meaning clinicians must interpret subjective findings cautiously and consider complementary objective measures, particularly when high suspicion of pulmonary hypertension exists despite reassuring subjective findings.
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Practical Takeaways
- •Subjective echocardiographic assessment of right heart changes should not be used alone to rule out pulmonary hypertension in horses; Doppler measurements are essential for diagnosis
- •Observers should be aware that lack of visible RH enlargement or dysfunction does not exclude PHT, particularly in early or mild cases
- •When RH changes are present on echo, they support a diagnosis of PHT, but clinical correlation and quantitative Doppler assessment remain necessary for confirmation
Key Findings
- •Inter-rater agreement for subjective RH assessment was low overall (61% perfect agreement, k=0.21), with significantly higher agreement among experienced observers (k=0.34) than inexperienced ones (k=0.18)
- •Intra-rater agreement was >80% in experienced observers (k=0.35-0.76) but <80% in beginners (k=0.33-0.54), demonstrating the critical influence of observer experience
- •RH changes had high specificity but low sensitivity for detecting pulmonary hypertension, meaning absence of RH changes does not rule out PHT
- •RH size and function abnormalities were more common in horses with Doppler-confirmed PHT, but subjective assessment alone cannot reliably exclude the condition