CONGESTIVE HEART FAILURE
• Definition:
Heart failure occurs when the output from the heart
is no longer able to meet the body's metabolic
demands for oxygen. Heart failure is an
important cause of illness and death in dogs and
cats.
Etiology
1. Mitral valve regurgitation. The mitral
valve is the valve that separates the
left atrium from the left ventricle.
1. Regurgitation means that blood moves
backwards from the ventricle to the
atrium when the ventricle is contracting,
instead of flowing out into the aorta and
then the body.
2. Mitral valve disease usually occurs from
chronic scarring of the valve (often due
to bacterial infection),
2. Dilated cardiomyopathy, where the heart muscle
becomes distended and incapable of properly
transmitting the electrical current of the heart beat
(more often seen in older, small breed dogs).
3. Cats, it usually associated with hypertrophic
cardiomyopathy, where the heart muscle becomes
too thick to work properly, and the chambers are too
small to move an adequate amount of blood with
each beat
Pathophysiology
When the ventricle's
performance and output
decline
the body activates several types of
compensatory mechanisms in order to
try to preserve blood pressure
and cardiac output
Many of the smaller blood vessels
will constrict, or narrow, to
The heart rate begins to increase
help raise the blood pressure
to get out as much blood
to the body as possible
The body starts to retain sodium
and water, also to increase
the blood pressure.
• When excessive pressure is found in the
ventricle during filling, edema begins to occur as
fluid begins to seep (ooze) out of the blood
vessels, into certain areas of the body, such as
• the lung tissue,
• around the outside of the lungs,
• and into the liver and abdomen leading to the so
called congestive heart failure.
Clinical signs
- Congestive heart failure is divided into left and right sided diseases.
- The clinical symptoms of each one are different.
A) Left sided congestive heart failure (CHF) (lung edema):
1- Respiratory distress- shortness of breath, and coughing
2- At first these symptoms may just be seen with exertion, but
eventually they are seen even at rest.
B) Right sided CHF is seen as:
1- Ascites, or fluid accumulation in the abdomen, causing a pot-bellied
appearance.
2- Sometimes, fluid accumulates in the chest, around the lung tissue,
causing compression of the lung tissue and heavy breathing.
In both cases, weight loss can be seen, as well as decreased appetite,
Diagnosis
1. History and clinical signs.
2. X ray and ultrasonography: for the mitral
insufficiency and the hypertrophic
cardiomyopathy.
Treatment
1. Diuretic medication to reduce fluid in the lungs and to make
the heart work.
2. Vasodilators are also often helpful to reduce the workload on
the heart.
3. Diet changes may be necessary to reduce salt (sodium)
intake, which in turn reduce retained fluids - especially in the
lungs. This decreases the workload for the heart.
4. Reduce exercise regimen to help control signs of CHF.
5. Continued monitoring to maintain a stable condition of CHF.
Prognosis
• The prognosis for heart failure is generally poor
unless the underlying heart disease is amenable to
medical or surgical therapy.
• Most of the causes are slowly progressive, and
patients seldom survive more than 6-12 months
with therapy.
Heat sound in pet animals (dog and cat) •
Questions