Introduction to atrial fibrillation
Atrial fibrillation is a disorder of the heart characterized by irregular heartbeat leading to improper functioning of the heart. Atrial fibrillation is the most common form of arrhythmia (improper rhythm and speed of heart beats) and is commonly noticed in adults above the age of 80 years with a higher incidence in men.1
Signs and Symptoms of atrial fibrillation
In many individuals, atrial fibrillation may not cause any signs and symptoms during the initial stages.
As the condition progresses, it may give rise to various clinical features such as:
- Irregular pulse
- Rapid heart beat (palpitations)
- Shortness of breath
- Feeling tired and poor exercise tolerance
- Chest pain
- Generalized weakness
At times, atrial fibrillation may cause formation of clots within the blood vessels of the heart.
Causes of atrial fibrillation
Atrial fibrillation is caused due to ineffective or improper functioning of the heart’s electrical system wherein the atria (upper chambers of the heart) tremble instead of beating/contracting regularly. This causes pooling of blood in the atria, which in turn leads to disturbances in the normal functioning of the heart.
Some of the most common underlying disorders and other risk factors, which lead to this irregular rhythm are:
- Long-standing hypertension
- Diabetes mellitus
- Excessive intake of alcohol and smoking
- Coronary artery disease
- Left ventricular hypertrophy
- Ischemic heart disease
- Congestive heart failure
- Any form of carditis
- Lung diseases
- An overactive thyroid gland
- Higher cholesterol levels1,2
Diagnosis of atrial fibrillation
The diagnosis of atrial fibrillation is based on a
- Comprehensive review of the signs and symptoms noted
- Physical examination
- Imaging studies
- Certain laboratory investigations
The examining doctor listens to the heartbeat with a stethoscope and also checks for the pulse rate.
Additional tests that are advised include blood tests (to rule out other underlying conditions) and imaging studies such as chest X-ray, ECG and echocardiography. In certain cases, specialized tests such as holter monitoring (continuous 24 hour ECG monitoring) and exercise testing may also be advised to get a clear picture of the functioning of the heart.3,4
Treatment of atrial fibrillation
Atrial fibrillation is treated by various approaches depending upon the severity of the symptoms.
Following are group medications that initially advised to regulate the heart rate.
- Calcium channel blockers,
- Cardiac glycosides
In certain emergency cases, the treatment option advised is the cardioversion, which may be electrical or pharmacological.
Electrical cardioversion: The patient is administered synchronized electrical shocks to manage the disrupted electrical signals of the heart.
Pharmacologic cardioversion: Medications or drugs (described before) are prescribed to the patients to slow down the heart beat associated with atrial fibrillation.
Some individuals may be treated with a technique known as radiofrequency ablation where in a burst of radiofrequency energy is used to destroy the tissue that triggers or blocks the abnormal electrical signals of the heart.
Implantation of atrial pacemakers or surgical correction of the abnormality may be required in certain individuals who do not respond well to the conservative approaches.
Maintenance of a healthy lifestyle is important in all individuals. Any underlying conditions are treated appropriately.1,4
Complications of atrial fibrillation
The complications of atrial fibrillation include the following:
- Stroke [most common in patients with advanced age]
- Congestive heart failure
- Myocardial infarction
- Arterial embolization
Prevention of atrial fibrillation
Prevention is always at most important in order to avoid atrial fibrillation and its related complications. Prescribed medications are to be strictly taken. The incidence of atrial fibrillation increases considerably with advancing age hence, regular physical exercise, proper diet and healthy habits play a vital role in its prevention.
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1.Medi C, Hankey GJ, Freedman SB. Atrial fibrillation. Med J Aust. 2007; 186(4): 197–202.
2.Dewar RI, Lip GY. Guidelines Development Group for the NICE clinical guideline for the management of atrial fibrillation. Identification, diagnosis and assessment of atrial fibrillation. Heart. 2007; 93(1): 25–28.
3.Kakar P, Boos CJ, Lip GY. Management of atrial fibrillation. Vasc Health Risk Manag. 2007; 3(1): 109–116.
4.What Is Atrial Fibrillation? Available at: http://www.nhlbi.nih.gov/health/dci/Diseases/af/af_what.html Accessed on 10-06-08.