I am getting heart palpitations in the winter. This is the third or fourth winter that it happens. I am feeling like my heart is bearing very hard and eventually this causes a feeling of tenseness or tightness on the left side of my chest which then starts to radiate even into my arm and the left side of my back. This usually goes away in the spring and I feel fine the rest of the year. I had my heart checked ( EKG , stress test) and nothing unusual was found (although this checkup was done in the fall when I was not feeling the palpitations). The palpitations seem to get worse when I am feeling stress or anxiety . I am a 35 year old male, nonsmoker, normal weight, try to exercise on a regular basis. I am going to get this checked out by a doctor but just wanted to get an opinion on what this could be. Thanks. Like I said, I find it strange that this only happens in the winter.