Fibrillation means rapid, irregular muscle contractions. Atrial fibrillation is a severe heart rhythm disorder (arrhythmia). Atrial fibrillation is a condition that is not life-threatening, as is ventricular fibrillation, though it is still a serious arrhythmia that must be treated.
The Cause of Atrial Fibrillation
The heart pumps blood into the body and contracts due to electrical impulses that form in the sinus node, located in the right atrium. The sinus node determines the speed at which the heart contracts. The impulses spread from the atrium, through the atrioventricular node and into the muscle of the ventricles. The impulses slow down slightly during their course, first contracting the atrial muscle, followed by the ventricles. During atrial fibrillation, the sinus node malfunctions and the impulses do not spread coordinately throughout the heart; rather they form in other cells of the atrium, causing the electrical activity of the atria to be chaotic. The disordered impulses thus circle continuously. The atria do not contract; they quiver with the fibrillation frequency of 600 convulsions per minute. Atrial fibrillation develops in the area of damaged cardiac cells. These can be damaged as a result of a heart attack and can be replaced by fibrous cells, which do not have the same properties of the original healthy cells. This is why irregular and disorganized electrical impulses can easily form. Cardiac cells can also be damaged by swelling of the heart muscle following cardiac surgery, lung disease or excess alcohol consumption.
Symptoms of Atrial Fibrillation
Atrial fibrillation is manifested primarily by an irregular pulse with varying force, and heart palpitations. Other symptoms include shortness of breath, fatigue, chest pain and nausea. Dizziness can also occur, leading to loss of consciousness due to poor circulation in the brain. Some patients can be affected by atrial fibrillation without manifesting any symptoms, until complications arise. Symptoms tend to be quite general and similar to those of many other diseases, therefore one should always keep atrial fibrillation in mind.
Complications of Atrial Fibrillation
Atrial fibrillation can result in two types of severe complications. The first is an embolism in the brain. During atrial fibrillation, blood remains in the atria because the heart does not empty completely. This can cause blood clots that can be transported with the blood flow from the left ventricle, into the brain. The clot can block major blood vessels and cause a stroke with subsequent damage to brain cells. This is why when diagnosing atrial fibrillation, blood thinners are administered in order to lower the risk of this complication. The second complication is not enough blood being pumped throughout the body, since the ventricles cannot function properly, and less oxygen reaches the body than is needed.
Diagnosing Atrial Fibrillation
A diagnosis of atrial fibrillation is based on clinical symptoms, an examination done by a physician, when a patient's pulse is difficult to palpate, and imaging methods. An important imaging method for diagnosing atrial fibrillation is an EKG, electrocardiogram. This is a painless and efficient examination that does not burden the patient. With the help of electrodes placed on the wrists, ankles and chest, the electrical potential of the heart can be monitored. The results are recorded on paper in the form of curves and waves. Atrial fibrillation has a characteristic recording that a specialist can reveal immediately.
Treating Atrial Fibrillation
Atrial fibrillation can be treated pharmacologically or with the help of an electrical cardioversion. Sometimes atrial fibrillation is permanent and cannot be fixed. The treatment of atrial fibrillation consists of interrupting the formation of random impulses, synchronizing the cells of the heart and returning function to the main impulse generator, i.e. the sinus node. This is the purpose of an electrical cardioversion. During a cardioversion, electrodes are applied to the heart, which send short electrical shocks. These stop the spread of impulses, cancel out all areas where the impulses were forming, and allow the cells of the heart to obey the sinus node again. This procedure is performed under short general anesthesia. Another option of interrupting the fibrillations is by the administration of antiarrhythmics. If the atrial fibrillation cannot be fixed, patients are prescribed blood thinners, usually Warfarin. This prevents the formation of blood clots in the heart, not allowing them to embolize. Long-term treatment with Warfarin has its drawbacks of course, such as an increased risk of bleeding.
Risk Factors for Atrial Fibrillation
Risk factors for the emergence of atrial fibrillation are cardiovascular diseases. These include defects of the cardiac valves, myocardial infarction or high blood pressure. These illnesses damage the cells of the heart and can therefore easily lead to arrhythmia. It is rare for atrial fibrillation to affect an otherwise healthy individual. Other risk factors of atrial fibrillation include genetic predisposition, age, obesity, diabetes, smoking and excess alcohol consumption. Fibrillations can accompany thyroid disorders, as its hormones influence the heart's function.
Preventing Atrial Fibrillation
Atrial fibrillation is the most common arrhythmia and its incidence increases with age, where incidences of other cardiac illness increase as well. Atrial fibrillation can have serious consequences and become life-threatening; therefore it should be properly diagnosed and treated. Within the prevention of atrial fibrillation, it is important to take good care of one's heart and blood vessels. Smoking, alcohol and overeating should be limited and exercise and physical fitness should be maintained throughout one's whole life. An annual preventative check-up with a physician is recommended. If an individual feels heart palpitations, shortness of breath, fatigue, chest pain, or experiences a short loss of consciousness, it is necessary to consult a physician who will suggest next steps and possibly refer the individual to a cardiologist.