Overview

Atrial fibrillation (AF) is an irregular heartbeat that can cause symptoms of skipped beats, shortness of breath, stroke, or in some cases fluid in the lungs or legs. Treating AF is mostly to do with slowing the heart rate down so that the heart can get a chance to regain some energy. In some cases, slowing the heart rate is not easy to achieve as some elderly patients find it difficult to tolerate medications and suffer the side effects of such treatments. In those instances, there might be a possibility to permanently control the heart rate by implanting a pacemaker in the heart and intentionally damaging a regulatory region of the heart called the atrioventricular (AV) node. Damaging the AV node by a procedure called ablation results in the AF not being able to influence the bottom chambers (the ventricles) resulting in a slow rhythm. Therefore, if a pacemaker is implanted then the heart rate can be completely regulated by the pacemaker.

A complex pacemaker that stimulates both the right and left ventricles simultaneously (BiVP) has been used for the last decade prior to AV node ablation. More recently, a technique has been designed to reduce the number of leads in the heart, reduce procedure time and have a similar effect on the heart called Conduction System Pacing (CSP). However, this has not been directly compared to BiVP in a robust randomized control trial. There is also not enough existing evidence to show that a pace and ablate strategy is superior to optimal medical therapy. We intend to compare the efficacy of BiVP to CSP in patients who undergo AV node ablation for treating AF, in addition to comparing both pace and ablate methods to pharmacological therapy.

Eligibility

Inclusion Criteria:

1. . Patients with permanent AF/persistent AF (in AF)
2. . Patients with NYHA Class II -IVa HF symptoms
3. . NT-proBNP ≥ 900 ng/L, or ≥ 600 ng/L if the patient has had a HF hospitalization within 1 year despite of guideline-driven medical therapy for HF of at least 3 months
4. . any QRS duration for patients with LVEF >35%, QRS duration <150 ms for patients with LVEF ≤35%

Exclusion Criteria:

1. In hospital patients needing intensive care or intravenous inotropic agent in the last 4 days
2. patients with a life expectancy of ≤ 1 year from non-cardiac cause or anticipating a transplant within 1year
3. acute coronary syndrome <4 weeks or coronary revascularization <3months
4. unable or unwilling to provide informed consent
5. uncorrected primary valvular disease or prosthetic tricuspid valve
6. restrictive, hypertrophic, or reversible form of cardiomyopathy
7. severe pulmonary diseases such as cor pulmonale or pulmonary hypertension (≥35mmHg)
8. patients enrolled in competitive clinical trials that will affect the objectives of this study;
9. existing CRT/BiVP or pacemaker
10. resting heart rate ≥110 bpm on Holter monitoring
11. patients who are pregnant or intend to become pregnant