Atrial Fibrillation - MAZE Procedure

Atrial Fibrillation is a fast, irregular heart rhythm where the upper chambers of the heart contract in an uncoordinated fashion. Normally, the heartbeat is triggered by an electrical impulse starting in the SA or sinoatrial node located in the right atrium and it travels across the atria, triggering it to contract all at once. The impulse then travels across the AV or atrioventricular node to the ventricles (the main pumping chambers of the heart) triggering them to contract. This is called sinus rhythm.  Atrial fibrillation occurs when this electrical impulse no longer travels from SA node to the AV node in the normal manner. Instead the impulse is diverted or scattered such that the atrium is no longer firing in a synchronous fashion, but is being activated one small section at a time. This lack of coordination results in a chaotic “fibrillation” that is very irregular. The electrical signal to ventricle through the AV node then becomes irregular and therefore the heartbeat is irregular. Atrial Fibrillation is dangerous because it may cause blood to pool in these chambers. The pooled blood can lead to clumps of blood called blood clots. A stroke can occur if a blood clot travels from the heart and blocks a small artery in the brain.

There are numerous ways to control and treat atrial fibrillation including medicines and interventions done by your cardiologist with a catheter.  There is also surgery.

The surgical intervention to treat atrial fibrillation is called the MAZE procedure. Through strategic placement of incisions in both atria, the circular electrical patterns that are responsible for this arrhythmia are interrupted and consequently the formation and conduction of errant electrical impulses is stopped. Scar tissue generated by the incisions permanently blocks the travel routes of the erroneous electrical impulses that causeatrial fibrillation, thus eliminating the arrhythmia. The heart's natural pacemaker originating in the SA node will resume with the normal electrical impulse.

The goal of the Maze procedure is to:

• ablate the arrhythmia
• restore synchrony between the atria and the ventricles
• preserve organized atrial contraction

Here at University Healthcare this procedure is performed in conjunction with another cardiac surgery procedure such as a CABG or heart valve surgery.