On a left ventricular pressure-volume loop, the area enclosed by the loop represents which of the following?

• A Stroke volume
• B Cardiac output per minute
• C Potential energy stored in the elastic elements of the wall
• D External work (stroke work) performed by the left ventricle per beat ✓

Explanation

Pressure-volume work equals the integral of pressure with respect to volume over one cycle, which is geometrically the area inside the loop. This area represents the external (stroke) work per beat. Stroke volume, option A, is only the horizontal width of the loop between end-systolic and end-diastolic volumes. Potential energy, option C, is represented by the triangle between the end-systolic pressure-volume point and the isovolumic relaxation path, not by the loop area.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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