Palpitations (noticeable pounding, fluttering or irregular heart beat) and pre-syncope (near blackout) are common ED problems sometimes due to an abnormal cardiac rhythm. This is difficult to diagnose as examination and electrocardiogram (ECG) are commonly normal and symptoms have usually resolved by the time the patient arrives in the ED. Diagnosing an abnormal heart rhythm as the cause of symptoms rests on capturing it on an ECG and patients are usually discharged with advice to return to the ED again for a 12-lead ECG should symptoms recur. The investigators will recruit 242 adult participants to either study or control arms. All study arm participants will be given an AliveCor Heart Monitor and trained in the use of the device. Control arm participants will receive standard care only. Both groups will be followed-up at 90 days. The investigators believe a smart phone based event recorder will allow better and earlier diagnosis in patients with a compatible smart phone or tablet, and revolutionise ED care in this area.