Understanding Heart Disease -- the Basics
The term heart failure does not mean that the heart has "failed" or stopped working. Rather, it means that the heart does not pump blood as well as it should to meet the body's needs. Heart failure is usually caused by coronary artery disease, but it can also be caused by thyroid disease, high blood pressure, or heart muscle disease (cardiomyopathy), among other conditions.
Heart Valve Disease
The heart has four valves (the pulmonary, mitral, tricuspid, and aortic) that open and close to direct blood flow between the heart's four chambers, the lungs, and connected blood vessels. A defective valve may fail either to open properly, obstructing blood flow (stenosis or obstruction), or to close properly, allowing blood leakage. Congenital heart disease and various infections, including rheumatic fever, are among the causes of valve disorders.
Here are diseases of the heart valves:
- Endocarditis, an infection that is usually caused by bacterial infection from staphylococcus and streptococcus. Bacteria may enter the blood and take root in the heart during illness, after surgery, or as a result of intravenous drug use. Endocarditis tends to strike people with pre-existing valve problems. The disease can be fatal if left untreated, but it can generally be cured with antibiotics. If heart valves are seriously damaged as a result of endocarditis, valve replacement surgery may be needed.
- Rheumatic heart disease, common earlier in the 20th century but now largely preventable with antibiotic treatment, stems from damage to the heart muscle and valves caused by rheumatic fever, which itself is associated with strep throat and scarlet fever. Symptoms of rheumatic heart disease are usually delayed for many years after infection. Rheumatic heart disease still occurs commonly in developing countries and may be seen in many immigrants to the U.S., but is extremely rare in people born and raised in the U.S.
Any disease of the pericardium, the sac surrounding the heart, is called a pericardial disease. One of the more common types of pericardial disease is a condition called pericarditis, inflammation of the pericardium. It is usually caused by viral infection, inflammatory diseases such as lupus or rheumatoid arthritis, or trauma to the pericardium. Pericarditis often follows open heart surgery.