Clinical trials

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 patients find it difficult to tolerate medications and suffer side effects from these treatments. In these 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). There is 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 CSP with AV node ablation to optimal medical therapy for treating AF.

Heart Failure (HF) and Atrial Fibrillation (AF) are two conditions that commonly occur together. Clinical guidelines consider a resting heart rate of 100-110 beats per minute (bpm) acceptable for patients with HF and AF while 72 bpm is considered the average in healthy populations. A higher resting heart rate indicates that the heart is working harder to meet bodily demands, and though it may be considered safe for patients with HF and AF to have a heart rate of 110 bpm, the investigators believe it is having a significant negative impact on patient quality of life and their ability to exercise. The current study will test exercise ability using a treadmill test before and after either a cardioversion, where the patient's heartbeat is reset using electric shocks, or a pace and ablate method, where the patient receives a pacemaker to regulate their heart rhythm and an ablation (intentional damaging) of the node that coordinates the beats within the heart. This will allow investigators to compare how the heart responds to exercise when the patient is on rate-control and anticoagulation medication therapy (before cardioversion or pace and ablate) and after the procedures. During exercise, the investigators will do a blood test that lets investigators know how efficiently the heart is working and record any symptoms experienced. The investigators will also collect information about the patient's quality of life. Using this information, the investigators hope to better understand whether the current standard of a resting heart rate of 100-110 bpm is ideal for patient quality of life.