Eileen
This problem is,indeed, viral, and causes inflammmation of he cartledge between the ribs, in my case. The pain can be literally breath taking, and can be relieved by antiinflammatorys. I've had this for years, and also thought it was a heart related. It took too long to be properly dx, but now have only occasional flare ups. Find a doctor familiar with this problem, otherwise you'll get blown off with stress, etc. etc.