Electrophysiological Study and Catheter Ablation
Catheter ablation for AF is an evolving procedure that is offered at only a limited number of larger hospitals.
Saint Thomas Heart providers have extensive experience in performing this complex procedure. In the EP study, a map of the heart’s electrical activity is created using a combination of advanced computer mapping technologies and imaging techniques. This map is used to pinpoint the areas of the atrium where the abnormal electrical signals are starting, and to confirm, after the ablation procedure, that the signals have been eliminated.
The latest technologies to perform catheter ablation are available at Saint Thomas Heart including: irrigated-tip radiofrequency ablation (heating) and cryotherapy ablation (freezing, also known as cryoablation). People with or without other heart problems including heart failure can be considered for these procedures.
Research has shown that AF usually begins in the pulmonary veins at their attachment to the left atrium. The pulmonary veins are large blood vessels that carry blood from the lungs to the left atrium. There are four major pulmonary veins and one or all may be involved in triggering AF. The goal of catheter ablation is to prevent unwanted electrical currents from traveling out of the pulmonary veins into the left atrium.
During the ablation procedure, long flexible tubes (catheters) are inserted into blood vessels in the groin (and sometimes the veins in the neck) and guided into the atrium. Using the electrical map, energy (heat or freezing) is delivered through the tip of the catheter to the tissue which has been targeted for ablation. When the abnormal signals have been eliminated, the normal rhythm is restored. As the tissue heals, it creates areas and lines of scar, through which the abnormal electrical signals are not able to pass. This is known as Pulmonary Vein Isolation (PVI). Many patients, especially those with persistent AF, have additional sources of AF outside the pulmonary vein. These sources will be identified and ablated as well with either cryoenergy or radiofrequency energy.