There has been a reply to your same question. Has there been any changes in your condition? Were you unable to find your orginal post?
>>>>An ekg is not a reliable source to make a diagnoses. If an ekg lists a possible abnormality, it requires further evidence from symptoms, other tests, etc. A good doctor evaluates your medical history, current symptoms, etc. A sinus rhythm probably would require more evidence for irregular heartbeats, etc...almost always not a source for chest pain.
To confirm there is left atrial abnormality (upper chamber) would require an echocardiogram to verify. That could possibly be a source for chest pain, if the abnormality is related to an increase in size of the atrium due a mitral valve insufficiency, etc...
Please confine your replys to the original, however, I have pasted the answer to your prior post. It helps to have your subject of interest, responses, additional questions. etc. contained on one thread. Thank you.