What causes abnormal heart beats?
Patient: My heart does this thing. It will be beating regularly, then suddenly it will beat a real hard pound, then it feels like a drum roll, then two more real hard pounds, then it feels like it skips a couple beats, then back to normal. This leaves me feeling like I m out of breath, but I m not and it exhausts me for about 2-3 minutes. What is it doing? And sometimes my left arm will hurt, and it has gone numb a couple of times. Am I headed for a heart attack? I m 58. Doctor: Hello and Welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.   I would explain that your symptoms could be related to a cardiac arrhythmia. For this reason, I would recommend you consulting with your attending physician for a physical exam and some tests:   - a  resting ECG and a cardiac ultrasound - an ambulatory 24-48 hours ECG monitoring to investigate for cardiac arrhythmia - blood electrolytes - thyroid hormone levels for thyroid gland dyfunction - complete blood count for anemia.   The pain in your left arm could be related to possible local inflammation or a pinched nerve. Anyway, an exercise cardiac stress test would help investigate for coronary artery disease.   Hope I have answered your query. Let me know if I can assist you further.