I was told that, when my son was a baby, he had a heart murmer and an extra beat at times . He had all the checks done and there is no sign of a hole in his heart. I checked his bp today (I have hypertension and bought the machine for myself) and his reading was 90/56. Should i be worried? He is of normal height + weight and leads an active life - cycling, snowboarding, skateboarding etc He is now aged 13.