I think you mean, What is a heart murmur? I have that since I was a kid. I don't worry much about it. "A heart murmur is an extra sound that the blood makes as it flows through the heart. Your doctor uses a stethoscope to listen to your heartbeat. When you have a heart murmur, your doctor can hear an extra whooshing or swishing noise along with your heartbeat." Here is the link to the site with more info. http://www.webmd.com/heart-disease/tc/heart-murmur-topic-overview
Your heart has valves and they squeeze your blood in a specific sequence. A heart murmur means that when listened to, the sequence does not match the established standard. If your are healthy I wouldn't worry about it. If you are overweight then it will lead to heart problems because now the heart will be overworked.