Systolic And Diastolic Function

Question 1

What measurements are used to check systolic function?

Answer 1

Fractional shortening
Ejection fraction
Pre ejection period 
Left ventricular diastolic size 
Size of ventricle in systole (if above normal then suggests systolic dysfunction)
Stroke volume and cardiac output

Question 2

What is preload?

Answer 2

The pressure which is exerted on the heart.

Question 3

What is fractional shortening?

Answer 3

2D m mode method using left ventricular end systolic and end diastolic values.
28-45% in the dog normal
30-50%in cat normal
Is a measure of systolic function NOT of contractility
Fractional shortening= (LVEDD-LVESD)/LVEDD * 100

Question 4

What 3 variables contribute to systolic function?

Answer 4

Preload, contractility, afterload

Question 5

What are common causes of increased pre- load?

Answer 5

Mitral valve disease
PDA
VSD
Many diseases will lead to increased preload

(HCM - less likely)

Question 6

How do you know if there is volume over load?

Answer 6

Measure the size of the left ventricle during diastole

Question 7

What is ejection fraction?

Answer 7

How much blood is pumped out in each contraction. Expressed as a percentage.
Ejection fraction = (stroke volume/ end diastolic volume) *100

Question 8

What is isovolumic relaxation time? IVRT

Answer 8

The time between the aortic valve closing and the mitral valve opening.

Question 9

What is a normal E/A ratio?

Answer 9

1-2

Question 10

What happens to the isovolumic relaxation time with an increase in left atrial pressure?

Answer 10

IVRT goes down
Higher pressure in the left atrium then the pressure in the left ventricle is over come much quicker and therefore the mitral valve will open quicker

Question 11

What happens to the IVRT of the aortic pressure increases?

Answer 11

It increases. More afterload to overcome.