Feasibility of identifying autonomic drivers for human Atrial Fibrillation
Atrial Fibrillation
All participants will receive a medication (Amiodarone) for at least 6 weeks prior to their procedure. Study participants will provide informed consent prior to commencement of the study protocol. The preparation for the procedure will be the same as for routine PVI with the patient receiving a general anaesthetic, trans-oesophageal echo (TOE) to assess for left atrial appendage thrombus and the left atrium accessed under TOE guidance as per usual clinic procedure. To start, the patient needs to be in a normal heart rhythm. This may already have been achieved with the Amiodarone but if not they will have a cardioversion ( a small electrical current to revert the heart temporarily to a normal rhythm). High frequency stimulation will be used to identify sites of nerve cells (ganglionated plexi) that can trigger ectopic beats and a map of these sites created. Once this is complete, these areas will be ablated. We will then re-test the sites to ensure there is no evidence of the nerve cells remaining. If the patient goes into AF before mapping is complete, then the sites already mapped will be ablated to trigger a return to sinus rhythm. If this doesn't work then the patient will have up to three cardioversions. If the patient is still in AF, we will map nerve cells that affect the heart rate which we know can be associated with ectopy triggering nerve cells. All patients will be followed up with heart monitors (24 hour Holters) at 3, 6, 9 and 12 months and at routine clinical appointments to see if the AF returns. We will compare their outcomes to a group with similar characteristics but who have received routine PVI treatment (taken from the routine data collected as part of the Cardiology department's routine auditing). We will use statistical tests to measure whether there is a true difference between the two groups.
1. Atrial fibrillation due to undergo an AF ablation procedure 2. Informed consent 3. Willing to attend follow up for Holter monitoring 4. Suitable for AF ablation procedure under general anaesthetic
1. Left Ventricular Ejection Fraction <35% 2. Left atrial size >4.8 cm 3. Failed cardio version with sinus rhythm lasting <1 week 4. Any significant co-morbidity precluding general anaesthetic or a contra-indication to ablation 5. Pregnant women 6. Patients with life expectancy less than follow up period 7. Unwillingness to attend follow up HoltersIf 8. Patients who have undergone previous experimental ablation procedures 9. Patients involved in research that could itself be affected by our intervention protocols