Atrial fibrillation

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at May 27, 2016
StartDiseasesAtrial fibrillation

Atrial fibrillation is a heart condition in which the heart rate is fast and irregular, which puts patients with this condition at risk for a stroke or heart attack. Atrial fibrillation can have serious consequences on the body. It is abbreviated as Afib and AF.

Contents

Definition & Facts

Atrial fibrillation refers to a condition where a person has a very fast, irregular heart rate. This occurs as a result of damage to the heart's electrical systems caused by underlying cardiovascular disease and exposure to certain kinds of drugs. All types of atrial fibrillation are classified under cardiac arrhythmias. It is the most common type of cardiac arrhythmia and can be largely asymptomatic. Individuals with this condition must be monitored closely by a cardiologist because of all the possible complications that can arise.

Symptoms & Complaints

A normal resting heart rate is usually between 60-100 beats per minute. Anything that is above or below this is considered irregular and a sign of heart problems. For a person with atrial fibrillation, their heart rate exceeds 100 beats per minute and may reach 175 beats per minute. Exercise becomes very difficult, and many find that they simply cannot do what they used to physically be able to.

Some patients experience dizziness and confusion. They may have bouts of breathlessness and weakness too. Patients might experience heart palpitations which is an uncomfortable awareness of one's own heartbeat. They may also experience a fluttering feeling in their heart and chest pains as well.

Causes

For the most part, the causes of disturbances in a person's heart rhythm are not fully understood. The sinus node (SA node) is responsible for sending electrical signals to the atrium, which causes the heart to contract and send blood to the ventricles. In hearts with atrial fibrillation, many different impulses are sent out, and the heart contracts irregularly and is unable to push the right amount of blood through.The back-flow of blood can lead to the formation of blood clots and reduce blood oxygen levels.

There are serious illnesses that can cause atrial fibrillation. One example is Graves' disease, which is a malfunctioning of the thyroid gland. Too much thyroid hormone is released, and it makes a person's heart rate and heart rhythm become irregular.

The consumption of caffeine and other stimulants can have the same effect as well. Studies have linked energy drinks to the onset of atrial fibrillation as well as over-the-counter caffeine pills. Atrial fibrillation can also be caused by the presence of other forms of heart disease, such as high blood pressure and congestive heart failure.

Diagnosis & Tests

To determine if a person has atrial fibrillation, testing is needed. Health care professionals will perform a physical examination and take the patient's medical history and family history. Tests that are commonly used include the Holter monitor. It is a type of electrocardiogram (ECG). It reads a person's heart rhythm for 24 hours through sensors that are connected by wires to the exterior of the chest. The information is recorded for a doctor to review. The reason it is done for a 24 hour period is because it is so difficult to pinpoint when the symptoms will present. The patient is told to record any times that they feel their heart flutter or race, so the doctor can compare the information to the ECG.

Another test that is used is the echocardiogram which is a sonogram of the heart. It allows for a visualization of the cardiac cycle in action. Any abnormalities can be recorded for the doctor to review, so they can look for instances of irregular functioning or deformities of the heart valves that could be causing AF. A cardiac stress test is also helpful because it allows the doctor to see what the heart looks like as a person exercises. Often, it is during times of activity when symptoms of atrial fibrillation are the most noticeable. Unlike the other heart tests, the cardiologist is always present during a stress test just in case there are any complications. 

Treatment & Therapy

The method of treatment used for atrial fibrillation is dependent upon the initial cause of the condition. If blood tests confirm it is due to a thyroid malfunction then the person might be prescribed drugs to block the production of thyroid hormones. Or, they might have their thyroid treated with radiation or completely removed.

If the condition is from the sinus node malfunctioning, or another form of heart disease, then beta blocker drugs are generally used. Beta blockers are effective and safe. Surgical options could catheter ablation in which a catheter is used to destroy the tissue that is obstructing the transmission of electrical impulses.

Sometimes, the atrioventricular node which receives the electrical impulse from the sinoatrial node and passes them along to the ventricles, would be destroyed via catheter ablation. A pacemaker would have to be inserted just under the patient's skin. The patient must be healthy enough to withstand the stress of the surgery and the anesthesia that is used. 

Prevention & Prophylaxis

For most cases of atrial fibrillation, there is little that can be done to prevent it. However, for patients with heart disease, the risk of developing AF can be reduced by taking all medication for heart disease exactly as directed. It is also important to avoid alcohol and tobacco products. Caffeine and stimulants of any type should not be consumed either.

Regular exercise should be done only to tolerance unless the doctor specifies otherwise. Lastly, daily psychological stress should be lowered as much as possible because emotional stress can sometimes trigger episodes of atrial fibrillation.