Fig. 2

Illustration showing definition of reference ranges. Upper part of the figure shows distribution in healthy individuals, with the 95th quantile used to define abnormal value. Lower part of the figure shows the ways for defining different degrees of abnormality. Patients falling above the 95th percentile of the healthy population but under the 97.5th percentile of the general population were classified as mildly abnormal; those between the 97.5th and 99th percentiles of the general population as moderately abnormal and patients over the 99th percentile of the general population as severely abnormal. The actual distribution density of this illustration was based on LV atrial volume distribution in males (indexed to BSA). BSA, body surface area; LV, left ventricle