If you know anything about plumbing, you already have a basic understanding of the physics of congestive heart failure, You see, the principles are the same...pipes are pipes, valves are valves, and pumps are pumps. They all work the same way.

We used to tell our kids..."it's physics". That's exactly what it is. You basically have two functions for the heart...collection on one side and circulation on the other. The right side is the collection side. The unoxygenated blood returns to the heart via the superior vena cava and fills the right atrium, then drops into the right ventricle and moves into the pulmonary circulation to pick up more oxygen.

After re-oxygenating, the blood then moves into the left atrium and drops into the ventricle to be ejected and circulated throught the body.

The blood moves from chamber to chamber via the valves. Valves are actually passive in nature, working on a principal of rising pressure forcing the valve open when the pressure in a chamber opens the valve to allow blood flow into the chamber with the lower pressure.

With congestive failure, one or both sides of the heart become less effective in their pumping action and blood then tends to back up in the system. It can cause downrane or uprange congestion in the circulation
 
With right sided failure, there may be swelling of the feet and ankles and can cause circulation impairments all the way back up to the heart. Liver congestion can occur in more extreme cases (portal hypertension). Weight gain can be on that list as well. Shortness of breath can be a trickle down symptom. Symptoms vary with each individual.

With left sided failure, the symptomology is principally pulmonary, with symptoms involving shortness of breath, fluid build up in the lungs, and possibly full blown pulmonary edema, whose principal symptom is pink frothy sputum.

The trickle down of all of this is extra cardiac workload, increased oxygen demand, and extra stress on the overall system.

Treatment includes improving symptomology...medication, sometimes stenting procedures, getting rid of any built up fluid, diet change, gradual increasing of activity based on exercise tolerance, and lifestyle changes.

The causes of failure are many. Those I'll run through another time.