Suggest Treatment For Heart Fluttering And Cough

I am a 59 year old female whose nine years post menopausal. My heart has fluttered over the past year and sometimes sort of makes me cough. But for three months now it is fluttering most of the day. In my job I work hard physically and am tall and slim with a 'mostly' vegetarian, low carb diet. I do experience a lot of stress though because I am married to an ADHD spouse with the accompanying crazy lifestyle. So what's going on? Is it just stress? Will it go away?