The purpose of the study is to assess combining AF ablation, with AV node ablation and pacemaker implantation for patients suffering with 'irregular heartbeats' or atrial fibrillation. The study will last 13 months.

Inclusion Criteria:

• Patients with symptomatic drug refractory atrial fibrillation.
• Patients who have had pacemaker implantation and AV node ablation with ongoing symptoms.
• Patients will already be refractory to at least 2 rate or rhythm control drugs.
• Patients must be over 18 years old.
• Patients give informed consent form prior to participating in this study.

Exclusion Criteria:

• Patient is suffering with unstable angina in last 1 week.
• Patient has had a myocardial infarction within last 2 months.
• Patient is expecting or has had major cardiac surgery within last 2 months.
• Patient is participating in a conflicting study.
• Patient is unable to perform exercise testing.
• Patient is mentally incapacitated and cannot consent or comply with follow-up.
• Patient has NYHA class III/ IV heart failure.
• Patient has LVEF <35% not secondary to tachycardia.
• Pregnancy.
• Patient suffers with other cardiac rhythm disorders.
• Recent coronary artery intervention or other factors suggesting clinical instability (ECG, clinical or laboratory findings).