What Causes Tightness In Chest Along With Heart Palpitations?

I have slight tightness in my chest close to my neck, I constantly have heart palpations. I notice when I eat something with high amounts of salt my heart races and I have trouble breathing. Along with that I have a little amount swelling or Inflammation in my arms and legs. I went to the doctor got my blood check but everything came back normal. Now I feel my heart beat in my butt. Do you what s going on.