What Causes Chest Pain While ECG, ECHO And Cholesterol Reports Are Normal?

hi, about 2-3 days my father had chest pain badly then we went to hospital. they did ecg,echo and cholestrol test and they are normal but the doctors are saying that although reports are normal but we are not assure it was a heart related or due to gas and to know about it you should do angiograpy. please help !!!