Heart failure describes the inability or failure of the heart to adequately meet the needs of organs and tissues for oxygen and nutrients. This decrease in cardiac output, the amount of blood that the heart pumps, is not adequate to circulate the blood returning to the heart from the body and lungs, causing fluid (mainly water) to leak from capillary blood vessels. This leads to the symptoms that may include shortness of breath, weakness, and swelling.
Understanding blood flow in the heart and bodyThe right side of the heart pumps blood to the lungs while the left side pumps blood to the rest of the body. Blood from the body enters the right atrium though the vena cava. It then flows into the right ventricle where it is pumped to the lungs through the pulmonary artery. In the lungs, oxygen is loaded onto red blood cells and returns to the left atrium of the heart via the pulmonary artery. Blood then flows into the left ventricle where it is pumped to the organs and tissues of the body. Oxygen is downloaded from red blood cells while carbon dioxide, a waste product of metabolism, is added to be removed in the lungs. Blood then returns to the right atrium to start the cycle again.
The FactsCongestive heart failure (CHF) is a condition in which the heart’s function as a pump is inadequate to meet the body’s needs. Many disease processes can impair the pumping efficiency of the heart to cause congestive heart failure. The symptoms of congestive heart failure vary, but can include:
- diminished exercise capacity,
- shortness of breath, and
- swelling (edema).
What Causes It?Many disease processes can impair the pumping efficiency of the heart to cause congestive heart failure. In the United States, the most common causes of congestive heart failure are:
- Coronary artery disease
- High blood pressure (hypertension)
- Longstanding alcohol abuse
- Disorders of the heart valves
- Unknown (idiopathic) causes, such as after recovery from myocarditis