Atrial fibrillation (AF) is the commonest arrhythmia in man, with an estimated prevalence of 1% under 60 years and increases rapidly with age to more than 10% in those over 80 years AF is the commonest arrhythmic cause for hospitalizations, and is associated with increased morbidity (adverse events) and mortality (risk of death).
Despite the prevalence of this condition, it was not until 1998 that the primary cause of AF was discovered. There are some areas of the heart muscle, usually located around the pulmonary veins which deliver oxygen rich blood back to the heart from the lungs, which, for some reason have retained autonomous and inappropriate rapid firing electrical activity and is capable of sending the whole of the atrium into a completely chaotic rhythm resulting in clinical symptoms.
During ablation for AF, in order to record the electrical signals and apply the ablation treatment to the appropriate area, the catheter electrodes have to be passed through a thin section of the heart which separates the right from the left side of the heart. This is called a Trans septal puncture. The electrodes are then placed around the openings of the 4 pulmonary veins and ablation treatment applied to the muscle.
This has the effect of electrically isolating each pulmonary vein from the left atrium. Consequently, any abnormal electrical signals arising from the pulmonary veins cannot be conducted to the atrium and cause Atrial fibrillation. The duration of the procedure may be slightly longer than for other types of ablation and a CT scan of may be required before coming to have the ablation as we have a particularly advance piece of equipment which allows extremely precise electrical mapping of a 3D image of the left atrium and pulmonary veins.