With a key FDA approval in hand for its cardiac ablation technology, devicemaker AtriCure (Nasdaq:ATRC) has its sights set on grabbing market share from industry giant Medtronic (NYSE:MDT). In December, AtriCure’s Synergy ablation system became the first medical device to receive U.S. Food and Drug Administration approval for the surgical treatment of atrial fibrillation (AF), the most common type of heart-rhythm disorder. The ablation system is approved for use in open-heart AF procedures that are performed in conjunction with other operations.