Bristol-Myers Squibb developed BMS-919373, a selective IKur inhibitor for use in atrial fibrillation, acute coronary syndromes, and paroxysmal atrial fibrillation. IKur is a repolarizing K+ current encoded by the KCNA5 gene and is expressed predominantly in the atrium of human. IKur is a potential atrial-selective target for the treatment of atrial fibrillation. BMS-919373 participated in phase II clinical trials to evaluate the effect on atrial fibrillation burden in patients with paroxysmal atrial fibrillation. In addition, in phase I clinical trials for patients with acute coronary syndromes. However, further, developments have been discontinued.