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.
A heart murmur is an extra sound in the heartbeat -- such as a ''whooshing'' -- that is caused by turbulent blood flow through the heart valves. Heart murmurs can be heard through a stethoscope and often are detected during routine physical exams. On further examination, your doctor may find that the heart murmur is innocent. If your heart murmur is related to more serious heart problems, your doctor may refer you to a cardiologist (heart specialist). Medication or surgery may be recommended to treat the underlying problem. With a thorough physical examination and proper tests, your doctor should be able to tell what causes your heart murmur. Heart Murmur Symptoms. Many people with heart murmurs experience no symptoms. However, some ...