Association between Cardiac Auscultation and Echocardiographic Findings in Warmblood Horses.
Authors: Hövener Jakob, Pokar Julie, Merle Roswitha, Gehlen Heidrun
Journal: Animals : an open access journal from MDPI
Summary
Cardiac auscultation remains a cornerstone of equine clinical examination, yet its reliability in detecting specific valvular pathology has been poorly characterised in warmblood horses; this retrospective analysis of 822 animals examined at a German referral centre sought to establish how accurately heart murmurs correlate with echocardiographic findings and whether murmur intensity predicts regurgitation severity or structural remodelling. Thorough physical examination identified murmurs in 653 horses (80%), predominantly left-sided systolic findings (68%), with 635 subsequently undergoing echocardiography that revealed mitral regurgitation in 77% and aortic regurgitation in 23%, whilst 31% exhibited cardiac chamber enlargement. Agreement between auscultatory diagnosis and ultrasound findings was substantial overall (Kappa 0.74) and near-perfect when single murmur–regurgitation pairs were present (Kappa 0.94), with left-sided systolic murmurs reliably indicating mitral disease (87% accuracy) and diastolic murmurs suggesting aortic involvement (81% accuracy). However, murmur grade correlated only fairly with regurgitation severity—particularly unreliable for distinguishing moderate from severe disease—and whilst dimensional changes associated with more advanced regurgitation, no independent relationship existed between murmur intensity and cardiac remodelling independent of the regurgitation grade itself. These findings validate auscultation as a practical screening tool for lateralised valvular disease in this population but caution against using murmur loudness alone to grade regurgitation severity or predict secondary structural changes, emphasising the continued necessity of echocardiographic confirmation in diagnostic and prognostic decision-making.
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Practical Takeaways
- •Cardiac auscultation is reasonably accurate for identifying which valve is affected in warmblood horses, particularly for detecting left-sided systolic and diastolic murmurs; however, echocardiography should still be performed for definitive diagnosis and severity grading
- •A soft murmur does not exclude significant valvular disease, and a loud murmur does not necessarily indicate severe regurgitation—murmur intensity is an unreliable standalone indicator of regurgitation severity or cardiac remodeling
- •Presence of dimensional heart changes (especially left atrial or left ventricular enlargement) typically indicates more advanced disease and should prompt careful prognostic counseling, as these changes correlate with higher-grade regurgitations
Key Findings
- •Agreement between auscultation and echocardiography was substantial (Kappa 0.74) with multiple murmurs/regurgitations and almost perfect (Kappa 0.94) with single murmur/regurgitation
- •87% of left-sided systolic murmurs were caused by mitral valve regurgitation and 81% of left-sided diastolic murmurs originated from aortic valve regurgitation
- •Fair agreement existed between regurgitation grade and murmur loudness, with good correlation for mild regurgitations but less reliable differentiation between moderate to severe regurgitations
- •Dimensional changes were associated with more severe regurgitations and higher-grade murmurs, but murmur intensity alone was not a reliable predictor of dimensional changes independent of regurgitation grade