Caz, I was told I had a murmer not to worry, so I didn't. I would have sporadic heart arrythmias and heart pain, and again, I was told not to worry, so I didn't. Well now I have aortic stenosis and will need a heart valve replacement in 5-10 years. You need to take an antibiotic before dental work and any surgery. Throughout the past year my murmer has worsened and I have notice left chest pain frequently. I am tired and get very tired going up the stairs. I take a beta blocker (timolol) and it really helps me control the irregular rythms and controls the release of histamine when stressed. A beta blocker will never hurt you. Believe me.