When I lay down at night I wake up many times feeling like my heart has stopped and I am gasping to catch my breath. I went to the Dr. and my blood work came back fine. However, my potassium level is at 5.7, which is marked as high. My Dr said my kidneys looked fine so he wasn t concerned. I will be seeing a cardiologist next week. My question for you is, is my potassium levels something that could be causing my breathing problems? Even when I am watching tv and start to doze off, I wake up feeling like my heart stopped and I can t catch my breath. This has been going on for about a month now and it is quite frightening. I don t feel that it is associated with anxiety, I feel like there is a much more serious problem. Also, I workout every day and I feel fine during exercise. It only happens when I try to sleep or when I am really relaxed. Any advice you have for me would be greatly appreciated. God Bless!