When listening to a child s heart, one expects to hear the first and second heart sounds, including splitting of the second heart sound. The physician should assume that the finding of innocent murmurs will occur in a normal examination. It must be evaluated just as any other observation, and its normality established. These skill come from experience, as expected. The table below describes 10 characteristics that can be described regarding each heart murmur.
Innocent murmurs are softer and more harmonic than pathologic murmurs.
Terms such as harsh, coarse, blowing, can add meaning to the description of the murmur but generally this is hard to convey to others. Murmurs arising from the right heart are altered by variation in systemic venous return due to respiration. No murmur begins in diastole and continues through the first heart sound into systole. The most common continuous murmur is the venous hum, an innocent murmur audible in many children placed in the sitting position. The most common pathologic continuos murmur is that caused by a ductus arteriosus.