DR WAQAS NAWAZ PMAS Arid Agriculture University, Rawalpindi Pakistan

1. Congestive heart failure
11-arid-926
Adeel Baig
11-arid-927
Arkim Mirza

2. Defination
• Any heart with a reduced ability to contract is considered
a failing heart.
• Heart failure and congestive heart failure are medical
syndromes in which a dog exhibits signs related to a
complex interaction between a failing heart and the blood
vessels.
• In heart failure, the blood flow is insufficient to supply
organs with enough oxygenated blood for proper function.
• In congestive heart failure, blood dams up in organs—
usually the lungs but occasionally in the body's other major
organs—and causes the congested organs to function
abnormally,

3. Types of Heart Failure
• systolic myocardial failure
• impedance to cardiac inflow
• pressure overload
• volume overload.

4. Systolic myocardial failure
• General reduction in the ability of the heart
muscle to contract.
• Identified with echocardiography
(ultrasonography). There is reduced wall
motion during contraction of the ventricles
(normal blood flow cannot be maintained)
• Etiology = trauma, infection, drugs or poisons,
electric shock, heat stroke, tumors. Some
cases have no known cause

5. impedance (obstruction) to cardiac
inflow
• Result in a decrease in blood flow.
• Etiology = external compression of the heart
(for example, fluid in the sac surrounding the
heart), diastolic dysfunction resulting in a stiff
ventricle and reduced ventricular filling, or
abnormalities to physical structures of the
heart.

6. Pressure overload
• Result of long-term increases in stress to the
heart wall during contraction
• Result from the obstruction of blood flow
from the heart or increased blood pressure
throughout the body or in the arteries of the
lungs.

7. Volume overload
• Result of any disease that increases volume of
blood in the ventricle(s), thus increasing blood
flow this can bring on signs of congestive heart
failure.
• Diseases = valve disease (for example,
degenerative valve disease of the atrioventricular
valves), left-to-right shunts (for example, patent
ductus arteriosus, ventricular septal defect), or
high-output states (such as those caused by
hyperthyroidism or anemia).

8. Systolic or diastolic dysfunction.
• Heart failure may involve systolic or diastolic
dysfunction.
• Diastolic dysfunction = not enough blood is
able to fill the heart before pumping.
• Systolic dysfunction = the heart is too weak to
pump out enough blood.
• Both conditions lead to poor circulation.

10. Compensatory Mechanisms
• Specific mechanisms to attempt to normalize functions and
offset negative effects disease is having on the body.
• In animal with dilated cardiomyopathy, blood flow is slowed
by heart's reduced ability to contract leading to a reduced
BP because less blood is pumped with each beat, body
compensates by SNS to increase ability of the heart muscle
to contract and increase heart rate. These responses
increase cardiac output and blood pressure. longterm use
of SNS in this way damages heart muscle and other organs.
• Damage again reduces ability of heart muscle to contract
leading to cascade of actions, including release of various
hormones, that result in another increase in blood volume
and blood flow.

11. cont
• Blood volume can increase as much as 30% in
pets with severe congestive heart failure
• progressive heart muscle failure and longterm
activation of these hormones in an effort to
normalize blood flow result in continued heart
muscle failure.
• Blood flow becomes further compromised
with progressive signs of congestive heart
failure

12. Signs of Heart Failure
• Signs depend on causes of heart failure and the
heart chamber that is affected.
• Left-sided congestive heart failure = signs
associated with a backup of pressure in the
vessels delivering blood to the left ventricle. Fluid
in the lungs and congestion (coughing, difficulty
breathing) are the most common signs.
• Many dogs with left-sided congestive heart
failure faint due to lack of blood flow to brain.
• They may also have a low heart rate and low
blood pressure and may collapse.

13. Right-sided congestive heart failure
• Results in increased pressure in the vessels
delivering blood to right ventricle and body's
veins and capillaries.
• This may cause fluid to build up in the
abdomen (ascites), the chest cavity, and the
limbs.

14. Biventricular failure
• Arise when both right and left ventricles are
not working properly, such as in dogs with
heart muscle failure resulting from dilated
cardiomyopathy or poisoning.
• Signs attributable to both forms of congestive
heart failure can be noted, although it is
common for signs of one to outweigh other.

15. Treatment
• Treat heart failure in order to improve heart
muscle performance
• Control arrhythmias and blood pressure,
improve blood flow, and reduce the amount of
blood filling the heart before contraction.
• All of these can further damage heart and
blood vessels if not controlled. It is also
necessary to reduce amount of fluid in lungs,
abdomen, or chest cavity.

16. Drugs
• Specific drugs, dosage, and frequency used vary depending
on cause and severity of heart failure and other factors.
• Diuretics are usually prescribed for managing fluid overload
in animals.
• Digitalis and digoxin, part of a group of drugs known as
positive inotropes, may be used to help heart muscle
contract.
• ACE inhibitors ( angiotensin-converting enzyme) and
vasodilators can widen blood vessels and thus lower blood
pressure.
• Beta-adrenergic blocking drugs (beta-blockers) and calcium
channel blockers are helpful in some cases of congestive
heart failure.

17. Nutrition
• Heart failure caused by a deficiency of a
nutrient can be treated by supplementation
with the missing nutrient.
• This type of heart failure is rare.

18. Low-sodium diet
• For dogs with severe congestive heart failure that
does not respond well to conventional treatment.
• Dogs with mild to moderate congestive heart
failure, severe sodium restriction is not needed,
but diets high in salt should be avoided.
• Sodium-free snacks should also be given in place
of regular treats. Salt should not be restricted in
dogs with heart disease that have no sign of
congestive heart failure(early activation of certain
hormones)

19. Other Treatments
• Dogs with severe left-sided congestive heart
failure and fluid in the lungs (pulmonary
edema) may not get enough
oxygen. Oxygen can be given by way of an
oxygen cage, tight-fitting mask, or nose tube.

20. Thoracentesis and abdominocentesis
• surgical procedures in which a needle is
inserted into the chest cavity or abdomen,
respectively, to withdraw excess fluid used to
treat dogs with congestive heart failure that
have an accumulation of fluid in these areas.
• Can lead to rapid improvement in signs, has
no significant adverse effects, and can be
performed on a regular basis, if needed.

21. Bronchodilator treatment
• Reserved for patients with longterm airway
disease.
• It is not typically used to treat congestive
heart failure exception to this is for dogs that
faint as a result of a brief cardiac arrhythmia
associated with heart disease such as
degenerative valve disease.

22. Cough suppressants
• Generally not recommended in the treatment
of congestive heart failure, because masking
signs of cough can worsen the underlying fluid
in the lungs. If, however, a dog diagnosed with
severe heart disease is coughing, and heart
enlargement on chest x-rays shows no fluid in
the lungs, the coughing may be caused by the
enlarged heart pressing on the airways. Cough
suppressants may be helpful for these dogs.