Heart disease has been the leading cause of death in the United States since 1921, according to the Centers for Disease Control and Prevention. Coronary artery disease, or CAD, is the most common form of heart disease, affecting an estimated 15.5 million Americans, notes the American Heart Association. Other forms of heart disease also affect millions of people of all ages, including rhythm disorders, heart muscle diseases, infectious and inflammatory conditions, and heart malformations.
Coronary Artery Disease
Coronary artery disease is typically caused by atherosclerosis, a chronic condition in which fatty deposits called plaques form inside artery walls and obstruct blood flow. Smoking, high blood pressure, high cholesterol, diabetes and other factors contribute to plaque formation and growth. Established plaques are prone to rupture, leading to formation of a blood clot within the affected artery. These clots further reduce the blood supply to the heart, commonly leading to a heart attack.
Heart Rhythm Disorders
An arrhythmia is a heart rhythm disorder. It may involve an irregular heartbeat, or the heart rate may be too slow or fast. Other forms of heart disease often cause arrhythmias. Chemical or hormonal imbalances, certain medications and heavy alcohol use can also cause an arrhythmia. Common symptoms may include the sensation of skipped, rapid or forceful heartbeats as well as dizziness or fainting. Atrial fibrillation is one of the most common arrhythmias, affecting an estimated 2.7 million to 6.1 million adults in the United States, according to the American Heart Association.
Heart Muscle Disorders
Cardiomyopathy refers to a disorder of the heart muscle tissue, which may be abnormally thin, thick or rigid. Some cardiomyopathies are inherited, while others develop because of another condition -- such as CAD, alcoholism or a viral infection. Inherited cardiomyopathies are most commonly diagnosed in children and young adults. As cardiomyopathy advances, the heart becomes progressively weaker. This may lead to heart failure, wherein the heart cannot pump enough blood to meet the body's needs. Typical symptoms include fatigue and shortness of breath.
Heart Infections and Inflammation
Infections and inflammation of the heart may be described as endocarditis, pericarditis or myocarditis. Endocarditis involves inflammation of the inner lining of the heart. Infective endocarditis primarily affects the heart valves, which control the flow of blood into and from the heart. Myocarditis involves inflammation of the heart muscle, and pericarditis refers to inflammation of the membrane surrounding the heart. Causes of heart inflammation include bacterial infections such as Lyme disease, viral infections such as rubella and some common upper respiratory viruses, toxins such as alcohol or cocaine, and autoimmune diseases such as lupus or hyperthyroidism.
Heart malformations are structural defects that occur when something goes awry during heart development in the womb. The heart association estimates heart malformations affect about 8 in 1,000 births. Common malformations include a defective heart valve or a hole in the heart. Severity ranges from tiny holes that often close without treatment to major abnormalities requiring surgical correction. Major malformations are often detected before birth or immediately after. Minor abnormalities may go undetected until adulthood. While heart malformations are often serious, survival rates are improving.