Your Pet’s Heart Problem
Heart Failure – Those words at first seem pretty self explanatory and scary. “Heart Failure” is a general phrase used to describe a basket of disease conditions involving the heart of your pet that can range from a minor murmur to a major problem affecting your pet’s health and well being.
Everyone knows the constant beating of a heart is essential for an animal to remain alive. The heart is a muscular pump that keeps blood circulating to and from the cells which make up all the organs in a body.
Blood consists of several components; the liquid portion is serum which transports vitamins and minerals, waste products of cellular metabolism, carbohydrates, fats and proteins consumed in the animal’s diet, hormones, cells of the immune system (White Blood Cells) and Red Blood Cells which carry life giving oxygen to all the cells of the body and carbon dioxide, a waste product of cellular metabolism.
In the healthy animal blood low in oxygen but high in carbon dioxide enters the right side of the heart via large diameter, thin walled veins called the vena cava (VC) into the right atrium (RA). The heart’s pumping action squeezes blood from the right atrium through to the right ventricle (RV), passing through the tricuspid valve. The roll of the tricuspid valve is to prevent blood from re-entering the right atrium when the heart next contracts, keeping blood flowing in one direction, in this case towards the lungs. Blood is pushed from the right ventricle through the pulmonic valve into the pulmonary arteries (PA) which feed blood into the lungs where gaseous exchange takes place. Red blood cells release the carbon dioxide they have carried from the cells and refill with fresh oxygen. From here the re-oxygenated red blood cells travel through the pulmonary veins (PV) which feed blood into the left atrium (LA), through the mitral valve (also called the bicuspid valve) and into the left ventricle (LV).
When the heart next contracts blood in the left ventricle is forced through the aortic valve into the thick, muscular aorta which distributes blood to the rest of the body via arteries under pressure.
A pet with ‘Heart Failure” develops, over time, defects that lead to inefficient pumping of blood. The heart muscle itself enlarges at first and then weakens to the extent that it cannot pump efficiently. As a result, insufficient oxygen reaches the cells in the organs of the body. Blood pressure gradients go haywire and fluid from the blood leaks out of veins causing oedema (fluid) in the lungs (think ‘heart cough’) and free fluid fills the abdomen (enlarged tummy). The blood filtering mechanisms in the liver and kidneys can be affected leading to serious complications. The perfusion of blood to the brain may be affected leading to dizziness or fainting. General muscle fatigue is common.
As with most medical conditions the earlier the problem is recognised the better the response to therapy. Heart failure therapy includes providing medication aimed at improving the pumping efficiency of the heart and stabilizing the blood pressure as well as reducing the extravascular fluid in the lungs and abdomen.
Heart Failure is not a death sentence. With appropriate diagnostics and therapy the rate of decline due to heart problems can be slowed significantly.