What is heart disease?
Heart disease is a general term that refers to a variety of acute and chronic medical conditions that affect one or more of the components of the heart. Anything that damages the heart or decreases the heart's supply of oxygen, makes it less efficient, or reduces its ability to fill and pump will disrupt the coordinated relationship between the heart, kidneys, and blood vessels and can harm not only the heart but the rest of the body as well. Heart diseases can be present at birth (congenital) or may be acquired.
About 600,000 people die of heart disease in the U.S. every year, according to the Centers for Disease Control and Prevention. That is about 1 out of every 4 deaths. Heart disease is the leading cause of death for both men and women.
Some common diseases of the heart include the following.
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 and organs, including the heart. Narrowed or blocked arteries can lead to angina, heart attack or stroke.
Angina is intermittent chest pain frequently caused by inadequate supply of blood and oxygen to the heart (ischemia). Angina symptoms usually do not appear until most of the blood flow is lost to an area of the heart, when it can cause chest pain upon exercise that worsens in frequency and severity over time. Chest pain that develops at rest or with minimum exertion is called unstable angina.
Heart attack (myocardial infarction, MI) is death of heart muscle cells due to blockage of blood flow in the coronary arteries that provide cardiac cells with oxygenated blood. This can cause an acute onset of chest pain. The forms of acute onset of chest pain that include heart attacks and unstable angina are called acute coronary syndrome (ACS).
Congestive heart failure (CHF) is when the heart is less effective at pumping blood or completely filling or emptying the chambers and less able to deliver oxygen to other parts of the body. Blood may back up into the legs, hands, feet, lungs and liver, causing swelling, and the affected person may experience shortness of breath and fatigue. 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 itself:
- Dilated cardiomyopathy—one or more chambers of the heart enlarge or dilate
- Hypertrophic cardiomyopathy—one or more of the walls of the heart thicken
- Restrictive cardiomyopathy—occasionally, abnormal material accumulates in the wall of the heart, reducing the flexibility of the walls of the ventricles
- Ischemic cardiomyopathy--decreased blood flow to the heart
- Idiopathic cardiomyopathy—no obvious cause
Myocarditis refers to inflammation of the muscle of the heart. It often presents with a rapid onset of shortness of breath or an irregular heart beat and can cause heart failure to develop quickly.
Pericardial disease is a disease of the sac surrounding the heart. Pericarditis, an inflammation of the pericardium, may cause increased friction "rub" and pain in the chest cavity.
Endocarditis is an inflammation of the membrane lining the heart and heart valves.
Atrial fibrillation is a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure, and other heart-related complications.
Heart valve conditions may include:
- Prolapse—part of the heart valve protrudes into the atrium, preventing a tight seal, which may lead to regurgitation (backflow of blood) 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, it is called pulmonary valve stenosis, aortic valve stenosis, or mitral valve stenosis.
A variety of conditions or factors can cause or contribute to the development of heart disease. Examples include:
- Alcohol use
- Amyloidosis—a rare, progressive disorder that occurs when abnormal proteins, called amyloids, are produced and deposited in various organs in the body such as the heart, causing tissue and organ damage
- Anabolic steroid use
- Atherosclerosis—deposits made up mostly of lipids form on artery walls, narrowing and hardening the arteries and causing decreased blood flow
- Autoimmune conditions such as lupus
- Congenital defects—those present at birth
- Diet, especially when high in saturated fat and cholesterol
- Drug use, such as cocaine
- Drugs used to treat cancer or AIDS
- Exposure to chemicals or toxins, such as mercury
- High blood pressure (hypertension)
- Infection caused by bacteria, viruses or fungi
- Injury or trauma
- Rheumatic fever—this rarely occurs in the U.S. now
- Sedentary lifestyle
- Smoking cigarettes
- Thyroid dysfunction (under- and overactive)