Symptoms

The symptoms of Atrial Fibrillation vary for each individual. Some people with AF experience little to no symptoms and can be unaware of their condition until diagnosed by a physician in a physical examination.

Because a heart in Atrial Fibrillation does not pump blood efficiently, others experience several, sometimes severe, symptoms that may affect their overall quality of life, including:

The amount of time a person experiences symptoms may depend on the type of AF the individual has. People with paroxysmal AF may experience symptoms occasionally, for a period of minutes, hours or longer until the symptoms end on their own. Those with persistent or permanent AF can experience symptoms until their condition is treated.

Diagnosis

Because of the sometimes unpredictable and intermittent nature of arrhythmias, diagnosing AF can be a challenging process. After establishing a thorough medical history and completing a physical exam, patients are often asked to complete a number of tests that help determine the severity of the condition and its potential risk factors, such as stroke. These tests may include:

Electrocardiogram (ECG)
An ECG is a simple test developed to record the electrical activity of the heart. Electrodes are placed on the patient’s arms and chest, and connected to a machine that records the electrical activity. An ECG may be performed during rest or exercise, and patients may be asked to hold their breath for short periods of time during the procedure.

A physician evaluates the rate and regularity of the electrical activity, the position and size of the heart chambers, and any damage that may exist in the heart.

Holter monitor
If an arrhythmia is not detected at a physician’s office, it may occur during normal, daily activities. A Holter monitor is a small, portable device used to record the heart’s electrical activity for a longer period of time – 24 to 48 hours. Like an ECG, electrodes are placed on the chest. The patient carries the monitor in a small pouch around the neck or waist.

Patients are often asked to keep a diary of their activities while wearing the monitor. The monitor data and diary are given to the physician, where they can be analyzed to detect an abnormal rhythm.

Tilt-table test
If a patient experiences symptoms such as lightheadedness or fainting, a tilt-table test is performed to determine the cause of the symptoms. In the test, the patient lies horizontally on a table. Blood pressure, heart rate and heart rhythm are monitored as the patient is moved from a horizontal to an upright position.

The tilt-table test may aggravate or produce symptoms such as fainting, dizziness, nausea, sweating or weakness. These reactions are purposely induced and are normal reactions to the test.

Electrophysiology (EP) study
If other tests fail to diagnose an irregular heartbeat, an electrophysiologist – a cardiologist that specializes in the diagnosis and treatment of heart rhythm disorders – often conducts an EP study to determine the type of arrhythmia or induce the arrhythmia. In the test, the electrophysiologist threads catheters – thin, flexible tubes – through a blood vessel and into the heart. The catheters have electrodes on the end, which can map the electrical impulses of the heart, stimulate the heartbeat, or temporarily stop an arrhythmia by administering electrical impulses.

The procedure is minimally invasive and is performed while the patient is lightly sedated. During the test, the heart’s electrical activity is monitored and recorded. After the test, the catheters are removed and the insertion site is closed.

EP studies are particularly effective when other tests have failed to capture an arrhythmia at the time of its occurrence, because the electrophysiologist may be able to induce the irregular heart rhythm. By triggering the irregular rhythm, the physician can understand where the irregular electrical impulses originate in the heart.

Blood tests
Blood tests are often conducted to rule out other conditions which may cause Atrial Fibrillation. Hyperthyroidism – overproduction of the thyroid hormone – and other chemical abnormalities in the blood may trigger AF episodes.

Stress tests
Many patients experience AF episodes or symptoms when they’re exercising or under physical exertion. To replicate these episodes, a patient may undergo a stress test, in which the heart is increasingly exerted through physical exercise. During the test, a patient may walk on a treadmill or ride a stationary bike while an ECG records the electrical activity of the heart and blood pressure is monitored. The pace or resistance of the exercise is increased gradually, until a target heart rate is reached or exercise is no longer possible because of chest pains or an extreme rise in blood pressure.

Occasionally, drugs are used to stimulate the heart rate of patients who are unable to exercise to the full extent of the test.

Published: January 1, 2007