Surgery for Atrial Arrhythmias
Atrial fibrillation (AF) is a well described rhythm disturbance that is more common with advancing age. It is estimated that over 30% of those with atrial fibrillation are > 80 years of age. In the United States, AF is the leading cause of hospitalization in >450,000 cases annually, and contributes to >99,000 deaths annually.
The heart consists of four heart chambers (two atria and two ventricles) connected through four heart valves. Each of these chambers should normally beat in a coordinated manner with the other chambers, thereby ensuring that blood flows efficiently into, thru, and eventually out of the heart.
AF is an abnormal rhythm in which the two atria (smaller chambers of the heart) suffer uncoordinated activation; instead of contracting and pushing blood forward, the atria quiver (fibrillate). This results in loss of coordinated atrial activity and inconsistent filling and pumping of the ventricles (the larger chambers). The effect of AF on individual patients varies greatly, and may manifest as:
- Fatigue.
- Palpitations (racing of the heart).
- Shortness of breath.
- Light headedness (often the result of low blood pressure).
- Loss of consciousness.
- No symptoms.
Besides these common symptoms, AF can lead to clot formation in the heart itself (most commonly in a portion of the heart known as the left atrial appendage); if this clot becomes detached and mobile, it may travel to the brain, causing a stroke. AF increases the risk of stroke five fold over the general population. It has also been shown that AF-related stroke is likely to be more severe than non-AF-related stroke.
The goals of AF treatment are:
- Conversion of AF back to sinus (regular) rhythm, if possible.
- Control of the overall heart rate if the patient remains in AF.
- Prevention of stroke.
- Prevention of compromised heart structure and function because of long-standing AF.
The first (non-surgical) options of AF treatment are:
- Medications to convert AF back to sinus rhythm or to control heart rate.
- Electrocardioversion (controlled shock) to convert AF back to sinus rhythm.
- Ablation techniques (creating scars in the heart to prevent or trap the electrical activity that leads to AF).
- Anticoagulation (making the blood “thin” with medication to prevent the formation of blood clots in the atria).
Should these treatment options fail to convert and/or prevent further AF, more invasive (surgical) techniques are considered, including: