According to the American Academy of Family Physicians and the American College of Physicians, atrial fibrillation is the most common form of arrhythmia, or abnormal heart rate, in adults. Furthermore, according to the Centers for Disease Control and Prevention, an estimated 2.66 million people will have atrial fibrillation in 2010. Left untreated, atrial fibrillation can have significant complications, including stroke, heart failure and death.
Definition
Atrial fibrillation is an electrical abnormality of the heart that causes the two upper chambers of the heart, known as the atria, to beat irregularly. As a result, the upper and lower chambers of the heart beat chaotically and blood is not efficiently pumped throughout the body.
Signs and Symptoms
According to American Family Physician, palpitations are the most common symptom of atrial fibrillation. In addition, as a result of the irregular heart rate and rhythm, the heart is unable to efficiently pump blood throughout the body, causing weakness, lightheadedness, confusion, chest pain and shortness of breath. Occasionally, people with atrial fibrillation are unaware of their condition until it is diagnosed after a routine electrocardiogram (EKG). Atrial fibrillation can be acute or chronic, and can occur at any age.
Causes
Atrial fibrillation occurs when the heart's normal electrical activity is disturbed. A common cause of atrial fibrillation is a structural abnormality of the heart. Conditions such as high blood pressure, myocardial infarction, valvular abnormalities, prior cardiac surgery and congenital heart defects cause an alteration in the heart's structure and, in turn, disrupt the cardiac pacemaker. Other causes of atrial fibrillation include hyperthyroidism, medication, alcohol abuse, viral infections and lung disease.
Diagnosis
Atrial fibrillation is diagnosed by a medical provider when atrial fibrillation is seen on an electrocardiogram. An EKG allows a medical provider to see and evaluate the electrical activity of the heart. According to the Mayo Clinic, additional tests may be ordered by a medical provider in order to diagnose and to identify potential causes of atrial fibrillation. An event monitor, holter monitor, echocardiogram, chest X-ray and routine blood tests may be ordered to aid the diagnosis.
Complications
Atrial fibrillation causes a disturbance in the efficacy at which the upper chambers of the heart pump blood. Normally, the atria contract pump blood out of the chamber. Atrial fibrillation causes the atria to quiver chaotically, enabling blood to pool and thereby increasing the risk of a blood clot forming within the heart, traveling to the brain and causing a stroke. In addition, untreated atrial fibrillation can cause the musculature of the heart to weaken and progress to heart failure or death.
Medications and Treatment
According to the American Academy of Family Physicians and the American College of Physicians, the recommended treatment strategy for the majority of patients includes medications for heart rate control and anticoagulation. Beta blockers such as atenolol, and calcium channel blockers such as verapamil, are two common drug types used to control heart rate. Chronic anticoagulation prevents the development of blood clots and therefore decreases the risk of stroke with atrial fibrillation. Most patients with atrial fibrillation should be treated with the anticoagulation medication, Warfarin, unless the otherwise advised by a medical provider.
Other treatment options include cardioversion and surgery. Cardioversion, achieved with either medication or electrical shock, is a method of resetting the heart's normal rhythm. Surgical procedures to correct atrial fibrillation have high success rates, but are usually reserved for cases in which medications fail to provide an acceptable response.
References
- Center for Disease Control and Prevention: Atrial Fibrillation
- American College of Physicians: Management of Newly Detected Atrial Fibrillation: A Clinical Practice Guideline from the American Academy of Family Physicians and the American College of Physicians
- American Family Physician: Atrial Fibrillation
- Mayo Clinic: Atrial Fibrillation
