I have an irregular heartbeat - what causes this? (possibly one for Dr Frank!!!)? I was ill recently and had to have an ECG. It showed an irregular heartbeat - so irregular that even though i was in no pain and had no symptoms of heart problems, i was kept in hospital overnight and had a repeat ECG every hour. The doc also printed out the ECG for me, and told me I must keep it with me at all times and make sure that those around me are aware of the condition because it looks as if I am having a heart attack - but I`m not! What causes this? Why is my heart totally different from anyone elses? the doc said it was the most irregular, otherwise healthy heart he had ever seen!!!