My 17 yr old son began having chest pains a week ago. He called an ambulance. The EMS ekg read that he had a sinus arrhythmia and enlarged right atrium. The ER doctor said his ekg was normal and the EMS ekg reading was not accurate. Another Ekg read right axis deviation. Why would the ekg read different within days? He can’t get in to see a cardiologist for 3 more weeks.