Atrial Fibrillation: Chronic Beta-blocker Use Versus As-needed Rate Control Guided by Implantable Cardiac Monitor

The goal of this study is to test the feasibility of guiding as-needed pharmacological rate control of atrial fibrillation (AF) by implantable cardiac monitors and to assess the impact of continuous beta-blocker therapy versus as-needed rate control on the following outcomes: (1) exercise capacity, (2) AF burden, (3) symptomatic heart failure, (4) biomarker assessment of cardiac filling pressures and cardio-metabolic health, and (5) quality of life in patients with atrial fibrillation and stage II or III heart failure with preserved ejection fraction.