SIMPLE numerical expressions are often used in medical practice to indicate the severity or degree of various features under consideration. A patient is said to have "1-plus" or "4-plus" jaundice. Another shows a "1-plus" or "4-plus" trace of albumin in the urine. One might readily dismiss a "slightest possible trace" as inconsequential, whereas a very large trace of albumin is practically never inconsequential, and makes one think of nephrosis. It was with these general thoughts in mind that in 1933 I suggested designating the intensity of systolic murmurs in 6 gradations.1,2 It seemed useful and desirable to do this, although it depended entirely upon the subjective auditory sensations of the observer, without any other accurate acoustic apparatus than an ordinary stethoscope. At first it appeared to many that there was no real value in this and, to others, that it was not feasible.
Six gradations were recommended, i.e., 1
Levine SA. Notes on the Gradation of the Intensity of Cardiac Murmurs. JAMA. 1961;177(4):261. doi:10.1001/jama.1961.73040300014012