The surgical MAZE procedure can be performed traditionally with a technique in which precise surgical scars are created in the left and right atria. It may also be performed using newer technologies designed to create lines of conduction block with radiofrequency, microwave, laser, ultrasound, or cryothermy (freezing). With these techniques, lesions and ultimately scar tissue are created to block the abnormal electrical impulses from being conducted through the heart and to promote the normal conduction of impulses through the proper pathway.

The MAZE procedure is reserved for patients who have atrial fibrillation and need open heart surgery for a heart valve repair/replacement and/or a coronary artery bypass to treat other heart problems (such as valve disease or coronary artery disease). Virtually all surgical approaches include excision or exclusion of the atrial appendage. The left atrial appendage is a small, ear-shaped tissue flap located in the left atrium. This tissue is a potential source of blood clots in patients who have atrial fibrillation. During surgical procedures to treat AFib, the left atrial appendage is removed and the tissue is closed with a special stapling device. This procedure is performed by cardiothoracic surgeons in close collaboration with the electrophysiologists.

Electrical cardioversion “resets” the heart to a normal heart rhythm to allow medications to successfully maintain the normal rhythm. Cardioversion frequently restores the normal heart rhythm, but its effect may not be permanent. During the procedure, short-acting anesthesia is given that puts the patient to sleep and an electrical shock is delivered through patches placed on the chest wall. This shock will synchronize the heartbeat and restore normal rhythm.

Ablation is one of the common, minimally invasive types of electrophysiology procedures. During ablation, an electrical frequency is delivered through flexible catheters inserted into the heart via a vein in the leg to eliminate tissue that either triggers or perpetuates atrial fibrillation. This procedure can eliminate or significantly reduce the severity and frequency of atrial fibrillation episodes in the majority of patients.

Ablation strategies used at TGH are highly individualized and tailored to each patient’s needs and include:

PULMONARY VEIN ABLATION

Because AFib usually begins in the pulmonary veins or at their attachment to the left atrium, energy is applied around the connections of the pulmonary veins to the left atrium during the pulmonary vein ablation procedure (also called pulmonary vein antrum isolation or PVAI). During the procedure, a physician inserts catheters (long, flexible tubes) into the blood vessels of the leg and sometimes the neck, and guides the catheters into the atrium. Energy is delivered through the tip of the catheter to the tissue targeted for ablation. Frequently, other areas involved in triggering or maintaining AFib are also targeted. Small circular scars eventually form and prevent the abnormal signals that cause AFib from reaching the rest of the atrium. However, the scars created during this procedure may take from two to three months to form. Once the scars form, they block any impulses firing from within the pulmonary veins, thereby electrically “disconnecting” them or “isolating” them from the heart. This allows a normal heart rhythm to be restored.

Because it takes several weeks for the lesions to heal and form scars after a pulmonary vein ablation, it is common to experience AFib early during the recovery period. Rarely, AFib may be worse for a few weeks after the procedure and may be related to inflammation where the lesions were created. In most patients, these episodes subside within one to three months.

NEW ABLATION WITH ADVANCED MRI MAPPING

Traditionally, a catheter is used to identify the areas of the atria to target for ablation. Tampa General Hospital is the only hospital in the Tampa Bay area offering a new advanced mapping technique done on the MRI, to provide better diagnostic information to develop a personalized treatment plan of areas to target and improves the success rate of ablation.

ATRIAL FLUTTER ABLATION

Atrial flutter ablation is a minimally invasive procedure where the physician targets the area in which the circuit for atrial flutter is located. By inactivating this tissue, the atrial flutter can be eliminated.

ABLATION OF THE AV NODE

AV node ablation is reserved for patients who have therapy refractory atrial fibrillation and/or atrial flutter not amenable to conventional ablation. During this procedure, catheters are inserted through the veins (usually in the groin) and guided to the heart. Radiofrequency energy is delivered through the catheters to sever or injure the AV node. This prevents the electrical signals of the atrium from reaching the ventricle.

This result is permanent, and therefore, the patient needs a permanent pacemaker to maintain an adequate heart rate. Although this procedure can reduce AFib symptoms, it does not cure the condition. Because the patient will continue to have AFib, an anticoagulant medication is prescribed to reduce the risk of stroke. It is important to note that due to better treatment alternatives, ablation of the AV node is rarely used to treat AFib.

SVT ABLATION

SVT (supraventricular tachycardia) ablations treat fast heart rhythms that come from the upper chamber of your heart. These rhythms can cause fast or erratic heart beats. Depending on the type of rhythm, symptoms or response to medications, SVT ablation can be the first or second line of treatment.

Tampa General Hospital heart rhythm specialists treat these rhythms by creating tiny scars in your heart to help block the abnormal electrical signals. The procedure is done with small, flexible tubes which can deliver heat or cold to help destroy the target tissue. 

COMPLEX ABLATION

There are times where Ventricular Tachycardia (VT) is unable to be treated with conventional ablation techniques. Stereotactic body radiotherapy (SBRT) is an additional technique for treating refractory VT and is recommended once medical therapy has been optimized and previous catheter ablation techniques have failed.

The heart rhythm specialists at Tampa General Hospital lead the field in treating refractory VT as TGH is one of the few locations in the state of Florida that can provide this type of specialized care.

Other approaches to ablation procedures we employ include:

• Posterior wall isolation achieved either by heat (radiofrequency energy) or freezing (cryoballoon ablation)
• Scar modification geared toward closure of discrete conduction channels within scar tissue by heat (radiofrequency energy)
• Ablation of associated focal arrhythmias or atrial flutters by point or linear ablation by heat (radiofrequency energy)
• Hybrid ablation procedures using both cryo- and radiofrequency energy