Arrhythmia Surgery

Questions & Answers

What is atrial fibrillation (Afib)?
Afib is a very common irregular heart beat which happens when the atria or upper heart chambers lose their ability to contract in a coordinated manner, and instead begin to quiver.

How common is it?
As many as 2.2 – 3 million people in the US have Afib, with 300,000 new diagnoses each year.

What are the symptoms of Afib?
Patients can feel a number of symptoms including palpitations, shortness of breath, chest pains, weakness, dizziness, or fainting spells.

Are there more serious complications of Afib?
Yes. Afib patients have a 5 – 10 fold increase in the risk of stroke. These patients can develop heart failure, and their risk of death is increased over time compared to people without afib. (Framingham Heart Study, 1998)

What causes Afib?
Afib can be brought on by a large number of factors including heart artery blockages, heart valve problems, hyperactive thyroid, or even excessive caffeine or alcohol intake. Heredity may play a role. It becomes more common as we age. For many people, there is no identifiable underlying cause.

What is the medical therapy for Afib?
For many years, medicines have been used to try to control the symptoms of afib. These have included beta blockers such as metoprolol and calcium channel blockers such as diltiazem to slow the rapid heart rate and decrease the feelings of heart - pounding. Digoxin has been used for similar reasons. There are many anti – arrhythmia drugs used to try to medically “convert” the heart back into a normal sinus rhythm. Many of these drugs have prohibitive side effects for some patients, particularly when taken for prolonged periods. Finally, coumadin is routinely used to thin the blood of afib patients, thereby decreasing the risk of the quivering left atrium and left atrial appendage harboring clot which can break free and cause stroke.

What other treatment options are there?
Many cardiologists will recommend a “cardioversion” during which the patient is sedated and a brief electrical shock is applied to the chest. This can “reset” the atria, restoring sinus rhythm. It is usually preceded by a transesophageal echocardiogram to make sure no clot exists within the heart. The long - term success of cardioversion at maintaining sinus rhythm is well below optimal, and patients will likely need to continue medicines and/or undergo repeat cardioversions over time.

Are there surgical procedures to treat Afib?
Yes. One is known as “AV Node Ablation”. The AV node is the electrical weigh station between the atria and the ventricles. One method used to try to diminish the symptoms of afib is for the doctor to destroy the AV node with a catheter procedure. This prevents the rapid impulses of the atrium from reaching the ventricle. Unfortunately, the patient must also receive a permanent pacemaker to activate the ventricles in the absence of atrial input. As well, the atria still quiver, with an ongoing need for blood thinners.

Where do the abnormal electrical impulses come from?
Based upon work by Haissaguerre, we now believe that the abnormal impulses may originate within the openings of the pulmonary veins which empty newly oxygenated blood from the lungs back into the heart.
(Reference: Haissaguerre M, Jais P, Shah DC et al. Spontaneous initiation of atrial fibrillation by ectopic beats originating within the pulmonary veins. N Engl J Med 1998;339:569-66.)

Are there treatment strategies that try to block these abnormal impulses?
Yes. Dr James Cox devised a surgery called the Maze Procedure 20 years ago in which he used scissors to carefully place incisions in the atria which he then sewed closed. One important part of the procedure includes cutting the tissue connecting the pulmonary veins to the heart and reconnecting them. The resulting linear scar tissue acted as electrical insulation, forcing the impulses to travel in a more normal direction. The operation was exceedingly successful. For the first time, Afib could be cured. However, the operation is time consuming, and requires opening the sternum and stopping the heart temporarily with use of the heart lung machine. These factors have limited application of this traditional Maze Procedure.

What is a “Catheter Ablation”?
Electrophysiologists have devised a minimally invasive procedure in which they insert long tubes or catheters from the groin and feed them up into the right atrium, using x – rays for guidance. The catheters then puncture the septum or wall between the right and left atrium. Once in the left atrium, the electrophysiologists use radio-frequency energy to place burns on the atrial wall which turn into insulating scar tissue. The procedure requires general anesthesia and takes from 3 – 8 hours to perform.

How successful is catheter afib ablation?
Catheter ablation is about 60% successful. The success rate can be improved to about 80% with multiple repeat procedures.

Are there complications of catheter ablation?
Some complications have occurred during catheter ablation including stroke caused by clot forming on the catheters while they’re in the left atrium. A potentially serious narrowing of the pulmonary vein openings from scar has occurred. Additionally, a handful of patients have developed a fatal connection between the esophagus and the heart called atrio-esophageal fistula.

What is a Mini-MAZE?
A Mini – MAZE is a minimally invasive surgical procedure done through small incisions between the ribs. The surgeon creates scar tissue on the left atrium in a precise manner to block abnormal impulses from traveling from the pulmonary veins out onto the rest of the left atrium. He does this with a radio-frequency clamp–like device which does not require cutting the heart. The surgeon also excludes the left atrial appendage, an out-pouching thought to be a source of stroke – causing clot in Afib patients.

Does the Mini-MAZE require using the heart lung machine or stopping the heart?
No. The Mini-MAZE is done with the heart beating.

How long does the Mini-MAZE take?
The procedure is accomplished in about 2 hours. The hospital stay is usually 2 – 3 days. The recovery at home including time off from work takes about 1 – 2 weeks.

How successful is the Mini-MAZE?
About 90 – 94% of Mini – MAZE patients are cured of Afib. Since this procedure is relatively new, we are still awaiting long – tern data to be collected. However, our early and mid – term results have been gratifying.

Have there been complications with the Mini-MAZE?
Like any surgery, there is a small risk of bleeding or of needing to make a larger incision during the procedure. There was one death reported in the medical journals related to bleeding during a Mini – MAZE. Since this surgery is done in an operating room by cardiothoracic surgeons (rather than by non-surgeons in an X-Ray suite), we feel this important risk is minimized. Our only complication thus far at Maine Medical Center has been a minor wound infection treated with antibiotic pills for 1 week.

Will I still need medicines after my Mini-MAZE?
Yes. Most patient will continue blood thinners and anti – arrhythmia drugs for 3 – 6 months following the procedure. After that, the drugs can usually be discontinued if the patient has a normal rhythm.

Can a MAZE procedure be done on me if I am having open heart surgery for another reason?
Yes. We call this a “concomitant” MAZE and it can be done using the same tools and techniques in conjunction with any other open heart surgery such as coronary artery bypass or valve surgery.

Watch a brief movie about the Mini-MAZE procedure.