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 the 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. The coronary blood vessels narrow gradually, and 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 (termed "unstable plaques"), an acute narrowing of the coronary artery can cause chest pain to develop at rest or with minimum exertion (termed "unstable angina"). It can even cause the death of an area of the myocardium as part of a heart attack (myocardial infarction). These forms of acute onset of chest pain are termed acute coronary syndrome.
Heart failure, usually called 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. Any gradual damage to the heart can lead to heart failure over time; most commonly, this is due to coronary artery disease, high blood pressure (hypertension), 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, although it often improves after treatment.
Cardiomyopathy is an abnormality of the heart muscle. It may be congenital or it may occur when the heart responds to external pressures or toxins. One or more chambers of the heart may dilate (dilated cardiomyopathy), causing the chamber(s) to increase in size. In other cases, one or more of the walls of the heart may thicken (hypertrophic cardiomyopathy). Occasionally, cardiomyopathy may also be due to abnormal material accumulating in the wall of the heart, which reduces the flexibility of the ventricle walls (restrictive cardiomyopathy). Cardiomyopathy may be due to decreased blood flow to the heart, exposure to chemicals that damage the heart (such as alcohol, cocaine and some drugs used to treat cancer or other conditions), or inherited muscle problems, or it may have no obvious cause (idiopathic cardiomyopathy).
Myocarditis refers to inflammation of the heart muscle. It often presents with an acute onset of shortness of breath or an irregular heart beat and it 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 (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 refers to inflammation of the membrane that lines the heart and heart valves. It may be due to a microorganism or an autoimmune process. When it is due to an infection, it oten can be difficult to treat.
Heart valve conditions may cause a variety of dysfunctions, including:
- Regurgitation (backflow of blood)
- Prolapse (where 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 (a narrowing of the opening, which can affect blood flow rate)