Final answer:
Increased afterload causes an upward shift and leftward movement of the pressure-volume loop, resulting in a decrease in stroke volume.
Step-by-step explanation:
Increased afterload, which refers to the tension that the ventricles must develop to pump blood effectively against resistance in the vascular system, has an effect on the pressure-volume loop. Specifically, it leads to an increase in pressure within the ventricles, resulting in an upward shift of the loop.
The increased afterload causes the ventricles to work harder to overcome the resistance and pump blood out, leading to an increase in systolic pressure and a decrease in stroke volume. This is represented by the loop moving towards the left, indicating a decrease in stroke volume.
Overall, increased afterload causes the pressure-volume loop to shift upwards and to the left, reflecting a decrease in stroke volume.