Surgical or catheter ablation of atrial tissue are the only curative treatments for atrial fibrillation (AF).

 

 

The principle aim of catheter ablation of AF is to restore the normal sinus rhythm in order to relieve symptoms associated with AF, and to minimize or suppress the associated risks of blood clot formation, cardiac failure and increased mortality.

 

Radiofrequency energy is delivered via intracardiac catheter to cauterize the sources (ectopic foci or stable circuits) which are triggering or maintaining the AF episodes, usually in the pulmonary veins and/or a segment of atrial tissue, by putting up linear barriers to interrupt the errant electrical waves responsible for AF.

 

Isolating the pulmonary veins cures the paroxysmal (intermittent) form of AF in 85% of patients (with no further medication required) and improves an additional 10% (with an antiarrhythmic drug but no need for anticoagulants). The longer the AF episodes, the more diffuse the atrial abnormality beyond the pulmonary veins. In persistent AF (lasting > 48h or where there is a history of electrical cardioversion) or permanent FA, isolation of pulmonary veins alone is less effective and should be combined with atrial tissue ablation to increase the success rate to 90%. However, tissue recovery – even minimal – during the healing process can require an additional ablation, usually performed after 1 – 3 months of follow-up, once the healing period is terminated and inflammation has disappeared.