Understanding Heart Disease -- the Basics
Heart Valve Disease continued...
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 this 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.
Cardiomyopathy (Heart Muscle Disease)
Diseases of the heart muscle, or myocardium, are collectively referred to as cardiomyopathies. When diseased, the myocardium becomes abnormally stretched, thickened, or stiff. Among the many potential causes of cardiomyopathy are genetic heart conditions, reactions to certain drugs or toxins (such as alcohol), and viral infections. Sometimes, chemotherapy for cancer causes cardiomyopathy. Often, the precise cause of cardiomyopathy is unknown. In any event, either the heart muscle becomes too weak to pump efficiently or stiffening prevents adequate filling of the heart.
When cardiomyopathy progresses to the point of causing serious arrhythmias or heart failure, the outlook for long-term survival is poor.
Sudden death is another outcome associated with some cardiomyopathies, including hypertrophic cardiomyopathy, which results in an abnormally thickened heart muscle. Hypertrophic cardiomyopathy has claimed the lives of several prominent young athletes.
If cardiomyopathy can be detected and treated early enough, symptoms can often be controlled and heart failure averted for many years. Occasionally, cardiomyopathy is relentlessly progressive despite the best medical management, and heart transplant surgery becomes the only option for long-term survival.
Congenital Heart Disease
Should anything go wrong in the formation of the heart during prenatal development, a baby will be born with one or more congenital heart defects. Such defects are quite common, occurring in about seven of every 1,000 babies.