Common Heart Diseases
Coronary heart disease (CHD) and Coronary artery disease (CAD) are the most common forms of heart disease. They are usually part of a systemic cardiovascular disease (CVD) – a narrowing of arteries in the heart and throughout the body over time due to a build-up of fatty deposits that form plaques (atherosclerosis). This narrowing can significantly limit the amount of blood carried by the arteries and decrease the amount of oxygen supplied to the tissues. As the coronary blood vessels gradually narrow, symptoms do not appear until most of the blood flow is lost to an area of the heart, when it can cause intermittent chest pain (angina) upon exercise that worsens in frequency and severity over time. When plaques suddenly enlarge and become unstable, an acute narrowing of the coronary artery can cause chest pain to develop at rest or with minimum exertion (unstable angina) or can even cause death of an area of the myocardium or heart attack (myocardial infarction); these forms of acute onset of chest pain are called acute coronary syndrome (ACS).
Congestive heart failure (CHF) causes the heart to become less effective at circulating blood and less able to completely fill or empty the chambers. As a result, blood backs up into the legs, hands, feet, lungs and liver, causing swelling, shortness of breath and fatigue. While any gradual damage to the heart can lead to heart failure over time, most commonly it is due to coronary artery disease, high blood pressure (hypertension), or heart valve damage (which can be either congenital or due to an infection) or a previous heart attack. If the cause is temporary, heart failure may also be temporary; however, it usually is a chronic condition that worsens over time, but may improve with treatment.
Cardiomyopathy is an abnormality of the heart muscle. It may be congenital or it may be a response by the heart to external pressures or toxins. One or more chambers of the heart may dilate (dilated cardiomyopathy), causing an enlargement in the size of one of the chambers of the heart. In other cases, one or more of the walls of the heart may thicken (hypertrophic cardiomyopathy). Occasionally, cardiomyopathy may be caused by abnormal material accumulating in the wall of the heart, reducing the flexibility of the walls of the ventricles (restrictive cardiomyopathy). Cardiomyopathy may also be due to decreased blood flow to the heart, exposure to chemicals that damage the heart (such as alcohol and cocaine and some drugs used to treat cancer or other conditions), to inherited muscle problems, or may have no obvious cause (called idiopathic cardiomyopathy).
Myocarditis refers to inflammation of the muscle of the heart. It often presents with an acute onset of shortness of breath or an irregular heart beat and can cause heart failure to develop quickly. It is often due to a viral infection.
Pericardial disease is a disease of the sac surrounding the heart. It may be due to a bacterial or fungal infection, trauma, an autoimmune process, cancer, or a previous heart attack. Infections of the pericardium may quickly become serious if left untreated. Pericarditis, an inflammation of the pericardium, may cause increased friction "rub" and pain in the chest cavity.
Congenital heart disease, which arises during fetal development, may potentially affect any part of the heart. The amount of dysfunction depends on what form the abnormality takes and the extent to which it alters the shape, integrity, and functionality of the heart.
Endocarditis is an inflammation of the membrane lining the heart and heart valves. It may be due to a microorganism or to an autoimmune process. When it is due to an infection, it frequently can be difficult to treat.
Heart valve conditions may cause a variety of dysfunctions, including:
- Regurgitation – backflow of blood
- Prolapse – part of the heart valve protrudes into the atrium, preventing a tight seal, which may lead to regurgitation and an increased risk of endocarditis
- Stenosis – narrowing of the heart valve opening, which can affect blood flow rate; depending on the valve(s) affected, this can lead to pulmonary valve stenosis, aortic valve stenosis, or mitral valve stenosis.