Page 192 - Feline Cardiology

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Acquired Valvular Disease

Key Points

• Acquired primary valve disease is usually degenerative in cats, although it is far less common than in dogs.
• Infective valve disease is even less common in cats.
• Many cats with infective endocarditis present with congestive heart failure due to severe mitral and/or aortic valve
insufficiency. If, during echocardiography, an oscillating, echogenic mass is visibly associated with either of these valves, the
clinician should be highly suspicious of infective endocarditis, and blood cultures are warranted.
• Treatment of congestive heart failure secondary to valve disease includes furosemide, an ACE inhibitor, and possibly
pimobendan. Long-term therapy (6–8 weeks) of broad-spectrum antibiotics is needed in patients with infective endocarditis.

DEGENERATIVE VALVE DISEASE annular dilation associated with diseases such as dilated
cardiomyopathy or left-to-right shunts, and in the
Degenerative valve changes that lead to significant val- absence of structural valve abnormalities.
vular regurgitation often result in myocardial remodel- Animals with mitral and tricuspid regurgitation
ing due to the volume overload. Because cats with usually present with systolic murmurs due to the blood
degenerative valve disease rarely develop the severe valve leaking back into the left or right atrium during systole.
thickening or prolapse that is frequently noted in canine The murmur is left-sided if the mitral valve is involved
valve disease, the cardiac changes secondary to ventricu- and right-sided with tricuspid valve degeneration. A
lar volume overload (left atrial enlargement, left ven- subset of feline patients will present without an auscult-
tricular enlargement) may be incorrectly ascribed to able murmur, with factors including a small volume of
cardiomyopathy, in particular unclassified cardiomy- regurgitant blood, eccentric regurgitant jet away from
opathy since ventricular wall thickness is normal. the body surface, or a low pressure gradient driving the
Secondary valve disease can also occur due to primary regurgitation in cats with elevated right atrial pressure
myocardial disease. For example, mitral regurgitation due to severe tricuspid regurgitation. Other physical
and structural changes to the anterior mitral valve leaflet limitations to ausculting a murmur may include purring,
often occur secondary to systolic anterior motion of the obesity, fractious behavior, etc. However, in most patients
mitral valve with hypertrophic obstructive cardiomy- with degenerative valve disease, the presence of a
opathy. Moreover, the mitral valve leaflets, chordae ten- murmur increases suspicion that the patient has heart
dineae, and papillary muscles may be distorted in cats disease.
with endomyocarditis or restrictive cardiomyopathy. Valve regurgitation can be mild and inconsequential
Functional, or secondary, mitral regurgitation may or it can be severe and lead to congestive heart failure
occur secondary to ventricular volume overload and (CHF). Severe mitral or tricuspid regurgitation is

Feline Cardiology, First Edition. Etienne Côté, Kristin A. MacDonald, Kathryn M. Meurs, Meg M. Sleeper.
© 2011 John Wiley & Sons, Inc. Published 2011 by John Wiley & Sons, Inc.

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