Atrial fibrillation is a very common disorder. It causes palpitations, shortness of breath, and dizziness, and critically it can lead to a stroke. There are many different types of treatment, one of which include a type of ablation called pulmonary vein isolation.
Atrial fibrillation means that your atria, the top chambers of your heart and the ones responsible for receiving blood, move very rapidly and can’t push blood down to your ventricles (the bottom pumping chambers) effectively. This happens because instead of the electrical signal starting from the top right of your heart, like it does in sinus rhythm, a whole barrage of uncoordinated electrical signals come from your pulmonary veins. This is the cause of AF in most people – about 10% have another source of the multiple electrical signals.
To treat this, one option is a pulmonary vein isolation. In this procedure, an electrophysiologist (a cardiologist with extra training in the electrical system of the heart) burns a line at the junction between the pulmonary veins and the rest of the heart. Electric signals that start in the pulmonary vein now can’t “get out” to the rest of the heart – and then the heart goes back to listening to the top right chamber, in sinus rhythm.
The success rate of pulmonary vein isolation varies greatly, partly dependent on the risk factors that led to the person having AF in the first place. Success depends on
- How long they have had AF for
- How old they are
- How overweight they are
- The presence of other diseases, such as obstructive sleep apnoea, high blood pressure, and heart disease
- How successful previous attempts at cardioversion have been
- The size and shape of their atria
Overall, the rate of success is somewhere between 60 and 80%, but the electrophysiologist will provide more specific numbers tailored for you.
Prior to the procedure, you will need a CT or MRI scan of your heart to create a 3D map for the electrophysiologist to use when they are creating the burn line within the heart.
The procedure itself is performed under a general anaesthetic in the cardiac cath lab, and you are discharged after a one night stay. If the procedure is unsuccessful, either immediately or later, repeat procedures may be required.
Risks include damage to the blood vessels used to get into the heart and stroke. Rarer complications include damage to the nerve supplying your diaphragm, narrowing of the veins going to the left side of the heart. The two most dangerous but rare complications are cardiac perforation, meaning the catheter going through your heart wall, and an atrioesophageal fistula, where an abnormal connection develops between the heart and the oesophagus, the tube you swallow food through. Recent studies have quoted a risk of around 3.5%, with the two most common complications being damage to the blood vessels and development of a pericardial effusion.