Almost a half-million new cases of atrial fibrillation or heart palpitations are diagnosed each year in the U.S. Also known as arrhythmia, or auricular fibrillation, this causes heart palpitations ,shortness of breath, fatigue, weakness, dizziness, confusion, fainting, foot and ankle swelling and coughs with foamy mucus. It's currently the most common problem regarding the heart's rhythm. The main cause of heart failure and a major risk factor for stroke is atrial fibrillation. The heart contains four chambers, where the two upper chambers are called atria which is where the blood enters.