My daughter who is 18 and otherwise healthy has within the past week experienced heart skips, racing, shortness of breath, chest pain, fatigue, weakness and numbness and ache in the left arm. Took her to ER, had chest xray, ekg, bloodwork--all showing normal results. Echocardiogram was suggested by ER but primary dr felt it would show anything since other tests were normal. There has not been any unusual stress excecess caffeine or any other issues causing stress. I am very concerned. Could this be a blockage or infection of the heart or possibly a lung issue causing the heart problems?