a heart murmur from the younger days can stay for a while, so you have been experiencing heart problems? like what exactly? have you seen a doctor?
Most heart murmurs are nothing to worry about. My oldest boy was born with a heart murmur but they can barely hear it unless they're listening very closely. It hasn't affected him in any way but it depends on how severe yours is.
You should talk to your doctor about your concerns, especially if you're experiencing anything different or heart related. Can I ask what you've been experiencing? Are you getting heart palpitations? Sometimes these can be as simple as having too much caffeine or not enough sleep. Regardless, it would be a good idea to get checked out, if nothing more than for your own peace of mind.