Atrial fibrillation (AF) and heart failure (HF) synergistically interact to exacerbate each other. However, treatment of one entity can greatly improve management of the other. Although historically, permissive medical therapy was the mainstay of AF management in the HF population, recent data strongly favor early, often invasive, intervention for AF to reduce hard HF outcomes. It seems that intervening earlier in the time course of AF, though still not excluding persistent AF from treatment, may have more pronounced effects.