One more question for you. You said your chamber was 4.4. Which chamber are you referring to? If it is your left atrium then keep in mind that the larger it gets the more apt you are to go into atrial fib. That is what happened to me. 4.4 isn't enlarged much but enlargement does indicate the heart is reacting to stress. I too am a nurse and oftentimes am not sure if I am making too much of something or not taking something seriously enough. I think it just goes with the territory. It is hard to evaluate your own symptoms objectively.