Atrial fibrillation (Afib) is the most common cardiac arrhythmia. The risk of developing Afib increases with age, and more than two million Americans are affected by it. Although younger people can be affected by Afib, it is more common in people over the age of 60. In developed countries, the number of patients with Afib is likely to increase during the next 50 years due to the growing proportion of elderly people. Atrial fibrillation is caused by abnormal electrical pathways in the heart and usually involves a rapid heart rate in which the upper heart chambers (atria) contract in a disorganized manner. In other words, the atria quiver rather than beat effectively.

Those who suffer from Afib may experience a combination of the following symptoms:

• Pulse may feel rapid, pounding, fluttering, or it can feel too slow
• Dizziness, light-headedness
• Fainting
• Fatigue
• Shortness of breath
• Sensation of tightness in the chest

Thrombosis is the formation of a clot (thrombus) inside a blood vessel, obstructing the flow of blood through the circulatory system. Thromboembolism refers to both thrombosis and its main complication, embolization, which occurs when an object (i.e., thrombus) migrates from one part of the body and causes the blockage of a blood vessel in another part of the body. The most feared consequence of disorganized atrial activity is the formation of a left atrial clot and the potential for thromboembolism.

If a patient has a number of symptoms or risk factors, the following tests are used to screen for Afib: Electrocardiogram (EKG). A noninvasive and inexpensive diagnostic test that records the electrical activity of the heart over time. Characteristic findings of Afib include absence of P waves, unorganized electrical activity in their place and irregularity of the R-R interval due to irregular conduction of impulses to the ventricles. Exercise electrocardiography. A stress test used to test a patient’s heart and to identify rhythm disturbances during exercise. The test gives a general sense of how healthy the heart is and screens for CAD.

Once atrial fibrillation has been diagnosed, several treatment options are available:

Rate control. This treatment method seeks to reduce the heart rate to normal range (about 60 to 100 beats per minute) and is more commonly used in the chronic Afib. Rate control medications include betablockers, cardiac glycosides and calcium channel blockers. These medications work by slowing the conduction of impulses from the atria to the ventricles.

Rhythm control. The goal is to restore the normal heart rhythm, called the normal sinus rhythm. Rhythm control strategy may include electrical cardioversion (restoration of the normal heart rhythm through application of a DC electrical shock) or chemical cardioversion (performed with drugs). However, cardioversion should not be performed without adequate anticoagulation in patients who have been in Afib for more than 48 hours.

Catheter ablation. This is a nonsurgical procedure, so recovery time is minimal and other surgical risks are avoided. Before the ablation is undertaken, an MRI or CT scan is performed to obtain an accurate picture of the heart structure and size. During the ablation procedure the catheters (thin wires) are threaded through a blood vessel in the groin, up to the heart. The CT or MRI image is aligned with a three-dimensional (3-D) map of the heart using a 3-D mapping
system and intracardiac echo. An intracardiac echo helps ensure safety and creates a roadmap for the Afib ablation procedure. The precision of this procedure reduces the incidences of short and long-term complications. Doctors apply radiofrequency energy to the target areas to destroy the abnormal electrical pathways.

Cox-Maze III Procedure. This is a less commonly used open-heart surgical procedure intended to eliminate Afib.