Pressure Volume Loops Week 4

Question 1

What is measured on the y (vertical) axis of eh pressure-volume loop?

Answer 1

Pressure

Question 2

What is measured on the x (horizontal) axis of the pressure-volume loop?

Answer 2

Volume

Question 3

How is time factored into a pressure volume loop?

Answer 3

Not based on time

1 loop = 1 cardiac cycle

Question 4

Which direction does the pressure-volume loop move in during the cardiac cycle?

Answer 4

Counter clockwise

Question 5

How are changes in stroke volume demonstrated on a pressure-volume loop?

Answer 5

Changes in stroke volume will alter the width (left to right) of the loop. The greater the stroke volume, the wider it will be.

Question 6

A change of the end-systolic volume point along an end-systolic volume relationship line indicates a change in what?

Answer 6

Afterload

If the line changed slope, the it would indicate inotropy change

The relationship of the volume left in the ventricle and the pressure that its at.

-this would be the area in the upper left portion of the loop

Question 7

A change in slope of the end-systolic pressure-volume relationship line indicates a change in what?

Answer 7

Can relate to diastolic heart failure

Question 8

Demonstrate changes in afterload with pressure-volume loops

Answer 8

Increasing afterload causes a decrease in stroke volume (width of loop) and an increase in ESV.

A reduction of afterload will have the opposite effect. Increased stroke volume (width of loop) and decreased ESV

*shifts curve up and to the right

Question 9

Demonstrate changes in preload with pressure-volume loops

Answer 9

There will be increased venous return.

EDV is increased while ESV remains the same. Therefor increasing stoke volume

Question 10

Demonstrate changes in inotropy with pressure volume loops.

Answer 10

Less volume and less pressure at end systole

*shift to the left