SAEVA Congress 2018 Proceedings | 12-15 February 2018 | ATKV Goudini Spa
Left ventricular volume overload pattern
An aortic root diameter that decreases from early to late diastole is a sensitive
indication of increasing severity of AR. Aortic root dilatation (> 9 cm) is common in
horses with long standing, moderate to severe AR, but does not predispose horses to
aortic root rupture. Left atrial enlargement is common, as the AR becomes more
severe, although significant MR does not usually develop until late in the course of the
disease.
Severe AR is present when the regurgitant jet extends beyond the septal leaflet of the
mitral valve, occupying 2/3rds or more of the left ventricular outflow tract. Horses with
louder murmurs of AR have longer regurgitant jets than those detected in clinically
normal horses. The area of the regurgitant jet at its origin, compared to the area of the
left ventricular outflow tract at its origin is probably another indicator of the severity of
the AR, as is a short pressure-halftime, indicating a rapid increase in left ventricular
pressure during diastole.
Spectral tracing of moderate AR
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