Congestive heart failure (CHF) is the build-up of fluid due to a heart defect where normally there is none (lungs, chest cavity, and abdominal cavity).

Clinical signs that you see with CHF depend on whether you have left sided CHF with fluid accumulation in the lungs or right sided CHF with fluid accumulation in the abdomen or chest cavity.

The standard treatment for CHF is with Angiotensin Converting Enzyme inhibitors (ACE inhibitors) and diuretics, both of which work by lowering the amount of fluid in the body thus pulling the fluid from the lungs or abdomen.

What is Congestive Heart Failure Secondary to Valvular disease?

• Congestive heart failure (CHF) is the build-up of fluid due to a heart defect where normally there is none (lungs, chest cavity, and abdominal cavity). CHF can occur for many reasons including cardiomyopathy, myocarditis, toxins, blood clots, congenital defects, pressure overloads, infectious diseases, endocrine diseases, heart worms, valvular defects, etc. One of the more common causes of CHF is caused by a problem or defect with the valves in the heart. These defects can occur in any of the four valves of the heart (aortic valve, pulmonary valve, mitral valve, tricuspid valve).
• Normal blood flow goes from the veins to the heart and then to the arteries and back to the veins. The valves in the heart allow blood to flow in only the one direction (toward the arteries) and prevent the blood from flowing backward into other chambers of the heart or into the veins. When there is a problem with the valves of the heart, it causes some of the blood to flow or back-up into the veins. This increases the fluid pressure in the veins and causes fluid to leak out. The increased fluid is what causes the clinical problems (see clinical signs below).
• Depending on which valve is affected you may have fluid leaking out into the lungs (left sided failure – aortic or mitral valve problems) or into the abdomen and chest cavity outside of the lungs (right sided failure – pulmonic or tricuspid valve problems).

Clinical Signs

• Clinical signs that you see with CHF depend on whether you have left sided CHF with fluid accumulation in the lungs or right sided CHF with fluid accumulation in the abdomen or chest cavity.
• What could you see at home if your pet has Congestive Heart Failure?
  Left sided CHF – In left sided CHF, you get fluid building up in the tissues of the lungs. The fluid in the lungs prevents proper breathing and decreases the ability to get oxygen to the body. The signs you could see at home would be exercise intolerance, coughing, wheezing, shortness of breath, or even pale white or blue gums. These signs are usually worse at night and sometimes are better after the pet gets up and moves around.
  Right sided CHF – In right sided CHF, you get fluid building up in the spaces around the outside of the lungs and/or in the abdomen. With the fluid build up in the abdomen you will often see abdominal distension, lethargy, and difficulty breathing or breathing with a large abdominal component (increased movement of the abdomen when breathing). With the fluid build up around the lungs you see difficulty breathing and an exaggerated effort on inspiration.
• What could your veterinarian see at your regular exam?
  • Left sided CHF – Some of the findings your veterinarian may see at a regular examination include rapid heart rate, coughing, crackles or wheezes in the lungs, increased effort to breathe, weak pulses, and/or a heart murmur. (A heart murmur alone does not mean your pet has CHF.)
  • Right sided CHF – Some of the findings your veterinarian may see at a regular examination include distension of the jugular vein, jugular pulses, enlarged liver, fluid in the abdomen, decreased lung and heart sounds, weak pulses, shallow respirations, and/or a heart murmur.

Diagnosis

• Left sided CHF – Left sided CHF is usually diagnosed by radiographs of the chest and signs of difficulty breathing. The left side of the heart is generally enlarged, the pulmonary vessels are enlarged, and a white patchy pattern is seen covering parts of the lungs. An echocardiogram (ultrasound of the heart) is often performed to diagnose the underlying cause and severity of the heart disease.
  
• Right sided CHF – Right sided CHF is usually diagnosed by radiographs of the chest and an echocardiogram. The radiographs often show right sided heart enlargement, an enlarged vena cava, and/or an enlarged liver. An echocardiogram is often performed to verify the underlying cause and determine the severity of the heart disease.

Treatment

• The standard treatment for CHF is with Angiotensin Converting Enzyme inhibitors (ACE inhibitors) and diuretics, both of which work by lowering the amount of fluid in the body thus pulling the fluid from the lungs or abdomen.
• ACE inhibitors work indirectly by stopping the activation of an enzyme (angiotensin) that tells the body to save fluid. Stopping the activation of this enzyme decreases the amount of fluid the kidneys try and save, thus decreasing total body fluid levels.
• Diuretics work directly by increasing the amount of urine the kidneys excrete thus lowering the bodies overall fluid amount.
• The most common medications your pet could be placed on initially are Enalapril (Enacard), an ACE inhibitor, and Furosemide (Lasix), a diuretic. Some common side effects of Enalapril and Furosemide are increased thirst and urination, nausea, appetite loss, and diarrhea. These medications can also affect the kidneys so close monitoring of the kidney blood values by your veterinarian will be needed.

Prognosis

• The underlying valvular problem causing the congestive heart failure is rarely curable. It is a disease that your pet will have for life. The CHF can be managed with medications, such as ACE inhibitors and diuretics. The long term prognosis depends on the extent of the valvular disease and the ability of the medications to control the CHF without causing detrimental side effects. With proper medication and monitoring, your pet may be able to enjoy many more months to years of normal, healthy, high quality life.