Hello, Thanks for posting your query of HCM Atrial fibrillation produces a rapid and irregular heart beat. It may be asymptomatic or may produce Palpitations, which are sensations of a racing, uncomfortable, irregular heartbeat or a flip-flopping in your chest Weakness Reduced ability to exercise Fatigue Lightheadedness Dizziness Confusion Shortness of breath Chest pain A doctor who examines you can easily diagnose it, if it is present at the time of examination and it can be confirmed by an EKG. If the AF is intermittent or paroxysmal, then one has to be examined at the time of its occurrence. Another method is to have a continuous recording of the heart s electrical activity with a Holter monitoring. If any episode of AF occurs during the monitoring it would be picked up. During Holter monitoring you can also mark the record if any symptom occurs and that will also help decide whether your symptom is due to AF or not. Best wishes, Dr. Noble Zachariah