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, a 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 also a common treatment option. During ablation, an electrical frequency is delivered via catheter to the targeted areas believed to be causing the irregular heart rhythm. Small scars eventually form and prevent the abnormal signals that cause AFib from reaching the rest of the atrium. Pulmonary vein ablation and ablation of the AV node are the two types of catheter ablation procedures used to treat AFib. Both are performed by an electrophysiologist (doctor who specializes in treating heart rhythm conditions).
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.
Ablation of the AV node - During this type of ablation, 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.
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. Click here to read more about this new technology.