Reliability and identification of aortic valve prolapse in the horse.
Authors: Hallowell Gayle D, Bowen Mark
Journal: BMC veterinary research
Summary
# Editorial Summary: Reliability and identification of aortic valve prolapse in the horse Hallowell and Bowen addressed a fundamental problem in equine cardiology: the lack of standardised, reliable criteria for diagnosing aortic valve prolapse (AVP) via echocardiography, a condition whose clinical significance remains poorly understood. Using input from practising equine cardiologists combined with empirical validation in healthy horses, the researchers established that long-axis views of the aortic valve provide the most reproducible imaging approach, with standardised protocols yielding good-to-excellent inter-observer and inter-day agreement (kappa >0.80) for both identifying AVP and measuring prolapse distance. Crucially, they demonstrated that ultrasound probe malalignment can artificially create the appearance of AVP—a critical confounder that can be minimised through rigorous technique—and identified that only the non-coronary cusp prolapses in the horses studied. Short-axis views proved less reliable and overestimated AVP prevalence (92% versus 76% in long-axis), whilst orthogonal imaging offered limited added diagnostic value. These standardised criteria enable farriers, veterinarians, and researchers to confidently identify and monitor AVP longitudinally, supporting future epidemiological studies to establish whether this finding carries pathological significance or represents a benign anatomical variant in the equine population.
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Practical Takeaways
- •Use standardized long-axis views with strict imaging protocols when screening for AVP to minimize false positives from probe malalignment
- •Avoid relying on short-axis imaging alone for AVP diagnosis as it produces more false positives; orthogonal views improve diagnostic confidence
- •Prolapse distance measurement is highly repeatable and suitable for tracking progression in individual horses over time
Key Findings
- •Long-axis echocardiographic views of the aortic valve provided good to excellent inter-observer agreement (kappa >0.80) for AVP identification when standardized imaging guidelines were used
- •Ultrasound probe malalignment can mimic AVP appearance, but prolapse distance measurement showed excellent reliability (kappa/ICC >0.8) across observers and days
- •Short-axis views identified AVP in 92% of cases versus 76% in long-axis, indicating higher false-positive rate in short-axis imaging
- •Only the non-coronary cusp of the aortic valve was observed to prolapse, confirmed with both 2D and 4D echocardiography