Heart disease is caused by conditions that affect the heart muscle, blood vessels, arteries, valves and the conduction system. Heart disease occurs as a primary condition, for example from a genetic abnormality or a secondary health problem as a result of another disease. Common heart diseases affect people of any age, gender and race.
Coronary Heart Disease
The Centers for Disease Control and Prevention reports that 12 million Americans have coronary heart disease. This disease is caused by atherosclerosis or buildup of plaque in the coronary arteries. The plaque partially or completely blocks the arteries in the heart, decreasing or stopping blood flow to the heart muscle. Lack of oxygen-rich blood damages the cells of the heart. Heart damage from coronary heart disease leads to heart attack, congestive heart failure (CHF) and heart rhythm disturbances.
Congestive Heart Failure
According to the American Heart Association, 5.7 million Americans have CHF. Congestive heart failure is a condition in which the heart cannot pump effectively. Predominantly, it is the left ventricle that fails: it cannot pump an adequate amount of blood to the rest of the body. Fluid backs up into the lungs and the right side of the heart causing shortness of breath and weakness. Over time, the right side of the heart will fail. Causes of CHF include atherosclerosis, heart attack, hypertension, valve disease and infections that damage the heart muscle. In rare cases, the cause is unknown and the condition is called idiopathic cardiomyopathy.
Mitral Valve Prolapse
The mitral valve is the valve between the left upper chamber of the heart, called the left atrium, and the left bottom chamber of the heart, called the ventricle. The mitral valve has two leaflets that open and close according to changing pressures in the left ventricle. The valve opens to allow blood to flow from the left atrium to fill the left ventricle and closes when the left ventricle is full. When the left ventricle contracts to pump blood out through the aorta to the rest of the body, the closed mitral valve prevents blood from being forced back up into the atrium.
With mitral valve prolapse (MVP), one or both of the leaflets is enlarged and does not close properly: when the left ventricle contracts, blood leaks back into the left atrium. Most people with MVP do not have symptoms. However, severe MVP causes arrhythmia or irregular heart rhythms, increases the risk of heart infections such as endocarditis, and leads to CHF.
Atrial Fibrillation
Donna D. Ignatavicius, MS, RN, and M. Linda Workman, PhD, authors of "Medical-Surgical Nursing: Critical Thinking for Collaborative Care", report that atrial fibrillation (AF) is a common arrhythmia affecting over 2 million Americans. In AF, the atria quiver rather than beat in synchrony with the ventricles. The fibrillating atria cannot fill or empty properly. Blood pools in the atria, forming blood clots and decreasing the amount of blood that flows into the ventricles. Additionally, AF causes an irregular and rapid heart rate. Patients with AF are at risk for low blood pressure and stroke.
References
- Centers for Disease Control: Healthy People 2010: Heart Disease and Stroke
- American Heart Association: Heart Failure
- "Medical-Surgical Nursing: Critical Thinking for Collaborative Care"; Donna D. Ignatavicius, MS, RN, and M. Linda Workman, PhD; 2006
