Atrial fibrillation

An electrocardiogram (EKG) is a recording of the heart’s electrical activity as a graph on a moving strip of paper or video monitor. The pattern that is generated by the electrical impulses reveals whether the heart rhythm is normal or if the heart muscle is damaged.

A continuous EKG is temporarily attached to an ambulatory (freely moving) patient for a 24-hour period (though it can be used for up to five days). This test can detect or diagnose abnormal heartbeats (arrhythmias), as well as cardiac ischemia. It can also help evaluate the effectiveness of any medications, especially antiarrhythmics, the patient may be taking.

These tests measure blood oxygen levels, electrolytes and other possible indicators of an underlying cause of AF.

Studies have shown that hyperthyroidism is commonly associated with atrial fibrillation. Patients experiencing their first suspected episode of atrial fibrillation will also likely be asked to undergo a thyroid test.

An electrocardiogram is performed while the patient exercises in a controlled manner on a treadmill or stationary bicycle at varied speeds and elevations. The reaction of the heart under exertion can be measured and evaluated. It may be ordered to assess the extent of artery damage and/or coronary artery disease.

This test uses sound waves to track the structure and function of the heart. A moving image of the patient’s beating heart is played on a video screen, where a physician can study the heart’s thickness, size and function. The image also shows the motion pattern and structure of the four heart valves, revealing any potential leakage (regurgitation). During this test, a Doppler ultrasound may be performed to evaluate blood flow in the heart’s chambers, the blood vessels of the arms and legs, and the carotid arteries in the neck. An echocardiogram is useful in detecting structural abnormalities that lead to atrial fibrillation. The evaluation of heart function is also helpful in selecting antiarrhythmic medicines, if needed.

This test uses a small transducer attached to an endoscope that is inserted through the patient’s mouth and throat, and into the esophagus (the long tube from the throat to the stomach). This will not affect the patient’s ability to breathe freely but might temporarily interfere with swallowing. Once positioned, the transducer can transmit a clear image of the heart’s size and function. It may be used to detect blood clots in the atria. It also allows better assessment of the structure and function of the heart valves.

A test that involves an electrode catheter that is fed through a blood vessel and into the atria and ventricles. Once in place, electrical activity is recorded to assess the presence and source of abnormal heart rhythms, or to see if there has been any progress from medical treatments.

These are commonly used in rate control of atrial fibrillation. These medications slow transmission of electrical impulses from the atria to the ventricles. Though these medications slow the overall heart rate during atrial fibrillation, they will not restore the heart to its normal rhythm. Beta blockers have shown to be useful in preventing arrhythmias following heart surgery.

These are commonly used in rhythm control of atrial fibrillation. These medications stabilize the heart rhythm, helping to maintain a normal rhythm. There is a wide variety of antiarrhythmics that may be used, depending on the patient’s condition, mostly their heart, lung and kidney function. Antiarrhythmics can also cause undesirable side effects so patients on these medications need to see their physician regularly.

Medications that inhibit the formation of blood clots. Anticoagulants are often administered before rhythm control in initiated to prevent existing blood clots from breaking loose or new ones from forming. It is usually also continued for several weeks after therapy has begun. Anticoagulants must be monitored carefully to avoid side effects such as bleeding.

Aspirin acts as an antiplatelet and may be given in conjunction with anticoagulants to prevent further cardiovascular complications.

Returns AF to a normal heart rhythm through either an electric shock or drugs. While most patients can be electrically cardioverted to a normal rhythm, only 60 percent can be maintained in a normal rhythm long term. Once again, anticoagulant therapy is frequently administered in conjunction with cardioversion. In patients who have atrial fibrillation for more than 48 hours, cardioversion should not be performed unless the presence of a clot inside the heart is excluded by a transesophageal echocardiogram and/or after three to four weeks of therapeutic treatment with warfarin (an anticoagulant).

Destroying (ablating) the tissues and pathways that are causing faulty signals. Recent research has identified the pulmonary veins in the left atrium as the trigger for AF in some patients. New techniques to isolate the pulmonary veins are being developed. This technique has some risks and is reserved for patients whose symptoms persist despite medical therapy.

A device that is usually implanted to keep the heart from beating too slowly. In patients with AF, a pacemaker may be used in conjunction with medication to help control the heart rate. Some types of pacemakers have special features to help suppress AF. In addition, in patients whose AF cannot be controlled with medications, the physician may perform a procedure to interrupt the electrical connection between the atrium and ventricles. This is called an AV node ablation. Afterward, the physician would implant a pacemaker to keep the heart from beating too slowly. The patient would still be in AF but not feel it.

Making small, careful cuts in the atrial wall, thus designing a maze of new pathways through which electrical signals can travel. Signals will travel through this newly created maze rather than randomly leaping from various parts of the heart, therefore reducing AF. The maze procedure is highly successful. Significant research is ongoing, including the use of minimally invasive techniques and robotic procedures. The procedure is usually done in conjunction with valve surgery. The left atrial appendage, which is a structure within the left atrium that commonly harbors thrombi, is usually obliterated or excised during this surgery.

Preparing questions in advance can help patients have more meaningful discussions with their physicians about their conditions. Patients may wish to ask their doctors the following questions related to atrial fibrillation (AF):

• I have noticed no heart changes. How can you tell I have atrial fibrillation?
• I sometimes feel some flutterings in my chest. Is that atrial fibrillation?
• Will certain conditions bring on an attack of atrial fibrillation?
• I have experienced atrial fibrillation since my bypass surgery. Will it go away on its own?
• Can you tell what type of AF I have? Is one type more dangerous than others?
• How can I tell if antiarrhythmia medicines are working? Are there side effects?
• How risky is a surgical procedure for fibrillation?
• Is cardioversion painful?
• Will treating my valve disease affect the atrial fibrillation?
• How serious does AF have to be to treat it surgically?

• You or a family member has symptoms of atrial fibrillation.
• The following occur during treatment:
  • Change in heart rate, rhythm or strength.
  • Chest pain, sweating and weakness.
  • Shortness of breath and swollen feet and ankles.
  • Pain in the calf of the leg while walking.
• New, unexplained symptoms develop. Drugs used in treatment may produce side effects.