• LV systolic function should be routinely assessed using 2DE by calculating EF from EDV and ESV. The biplane method of disks (modified Simpson's rule) is the currently recommended 2D method to assess the LV EF.
  EF = (EDV - ESV)/EDV
• Normal LVEF is 63+/-5% using the biplane method of disks
• Among individuals aged > 20 y.o., LVEF in the range of 53-73% should be considered normal.
• LVEFs of <52% for men and <54% for women are suggestive of abnormal LV systolic function.
• Two-dimensional speckle-tracking echocardiography(STE)-derived global longitudinal stain (GLS) appears to be reproducible and feasible for clinical use and offers incremental prognostic data over LV EF in a variety of cardiac conditions, although measurements vary among vendors and software versions:
  GLS(%) = (MLs - MLd)/MLd
  ML is myocardial length at end-systole (MLs) and end-diastole (MLd). Peak GLS is a negative number because MLs is smaller than MLd.
• GLS measurements should be made in the three standard apical views and averaged.
• All references to stain changes should specifically mention an increase or decrease in the absolute value of stain.
• A peak GLS in the range of -20% can be expected in a healthy person, and the lower the absolute value of strain is below this value, the more likely it is to be abnormal.