The purpose of this study is to determine if physiologic pacing will improve symptoms and outcomes in patients with symptomatic first-degree heart block (pr interval ≥250ms). Patient will undergo a comparative effectiveness study where patients with symptomatic first-degree heart block (pr interval ≥250ms) undergo left bundle pacing (3830 lead) and are randomized to DDD-50 vs Managed Ventricular pacing-50 (MVP-50; AAI-DDD 50) and undergo a crossover at 3 months. This study will compare two standard of care options utilizing Food and Drug Administration (FDA) approved devices. Patients are evaluated at baseline, 3 months, and 6 months in terms of patient symptoms, exercise capacity, arrhythmia burden, and patient activity.
