change in left ventricular systolic blood pressure absolute change in left ventricular systolic blood pressure 2012-08-13T01:16:23Z Calculated measurement of a difference in the pressure within the heart left ventricle at the point of maximal contraction, when the blood is forced from the left ventricle into the aorta, between two points in time or two conditions expressed as the result of the subtraction in and of itself without comparison by ratio with another quantity. JSmith The term "absolute change" refers to the subtraction of one value from another, as opposed to a dissimilarity of two values expressed as a ratio or as a percentage. In this context it is not intended to necessarily imply the difference expressed as an absolute value |n|, that is, the numeric value of the difference without regard to its sign.