I thought I'd post regarding this, I went in for a heart murmur check recently for the class 1 medical here in Australia, I'm only 24 and had not seen the murmur on my first medical 2 years ago, and was a little concerned but found out it was nothing to worry about and I have my class 1 coming back soon, cost a fortune though to get the echocardiogram done, and fortunately didn't have to do any other tests such as the 24hr monitor which helped a bit, seems that these things come up fairly often with healthy people and they aren't much concern