Unlike total range, the interquartile range has a breakdown point of 50%, and is thus often preferred to the total range. The IQR is used to build box plots, simple graphical representations of a probability distribution.igure 3. Box-and-whisker plot with four close and one far away extreme values, defined as outliers above Q3 + 1.5(IQR) and Q3 + 3(IQR), respectively. The interquartile range is often used to find outliers in data. Outliers are observations that fall below Q1 - 1.5(IQR) or above Q3 + 1.5(IQR).
Medical Definition of Heart murmur. Heart murmur: An unusual, 'whooshing' heart sound that may be innocent or may reflect disease or malformation. A heart murmur is created by blood flow through a heart valve, by blood flow through a narrowed chamber, or by an unusual connection between the chambers, as seen with congenital heart disease.
Systolic heart murmur. Systolic heart murmurs are heart murmurs heard during systole. They can be classified by when the murmur begins and ends, between S1 and S2. Many involve stenosis of the semilunar valves or regurgitation of the atrioventricular valves.