What Are Recurring Sensation Of Tightness In Chest Suggestive Of?

Hi I am a 40 year old male who is not overweight and is relatively fit and healthy. I few weeks a go I had tightness in my chest that lasted only a short while. THen about 14 days ago I had another bought of this tightness it lasted a about 24 hrs and I went to the ER. They did an ECG that was fine and a chest x ray which was fine. My blood tests showed slight levels of Troponin but according to the ER Physician not enough to warrant me staying in Hospital. He ordered a stress test the next day which appeared ok. I have also had another blood test ordered by my own doctor which showed Ferritin levels at 278. I am due to see a cardiologist on Monday but I continue to feel lethargic and very edgy.