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Question 6#

The end-systolic pressure-volume line:

A. Provides a good estimation of left ventricular compliance
B. Uses small changes in preload and afterload between cardiac cycles to determine contractility, which is represented by the x-intercept of the line
C. The slope will become steeper if contractility is increased
D. Requires preload to be held approximately constant to be measured

Correct Answer is C

Comment:

If pressure-volume loops are constructed for each cardiac cycle, small changes in preload and/or afterload will result in shifts of the point defining the end of systole. These end-systolic points on the pressure versus volume diagram describe a straight line, known as the end-systolic pressure-volume line. A steeper slope of this line indicates greater contractility.