One of the key roles of the human heart is to pump blood throughout the body. Congestive heart failure is a condition in which the heart does not pump enough blood to meet the needs of our body. Before we try to understand what congestive heart failure really is, let’s see how the heart handles blood circulation:
Four Steps Of Blood Circulation
- Step 1:The heart has four chambers, which pump and pause in sync with each other. Let’s start from the right top chamber, which is called the right atrium. Impure blood, with carbon dioxide, arrives here from rest of the body.
- Step 2: When this chamber is full, a valve opens, to allow blood to flow down into the chamber below it, the right ventricle. The right ventricle then pumps this blood sideways to the lungs, which take out the carbon dioxide and fill the blood with fresh oxygen that we have just breathed in.
- Step 3:This oxygen-rich blood is now sent from the lungs to the left atrium. When this chamber is full, it empties blood into the left ventricle right below it.
- Step 4: The left ventricle is the last chamber of the heart, from which pure, oxygen-rich blood is sent to the whole body.
‘Congestive Heart Failure’ or simply ‘Heart Failure’ happens most often due to defects in step 4 or in step 2. Two things to remember: (i) We are talking about the majority of heart failures; there are always exceptions. (ii) The process we are describing happens over months and years before a heart actually fails.
What Causes Congestive Heart Failure?
- When the left ventricle is unable to push oxygen-rich blood out to the rest of the body, this blood is pushed back to lungs first. The lungs are drenched in more blood than they can handle. As a result, breathing begins to become laboured.
- Blood also gets pushed back from the lungs to the right ventricle. If that is also failing, due to a faulty valve, the blood goes back to veins.
- When the blood goes back in the veins, fluid from the blood starts to leak from the vein into the tissues, causing swelling. You can see this swelling in the legs, especially near the ankles.
- Swelling can also happen in the lungs, abdomen & liver, as blood congests and backs up. When the fluid is retained in the body, weight increases.
With time, as the swelling and pressure increases, the left or the right ventricle, or in some cases, both sides of the heart get tired from the effort. The walls of the chambers can become too thick or too thin and eventually, collapse. This leads to Congestive Heart Failure or CHF.