Regulation of Cardiac Output

Question 1

What is the Frank-Starling Mechanism?

Answer 1

Intrinsic ability of heart to adapt to changing volumes of blood.

Question 2

If there is an increase in the stretching of the heart muscle during filling what would happen to force of contraction and amount of blood in the aorta?

Answer 2

It would increase the force of contraction and increase the amount of blood to the aorta.

Question 3

What does the ventricular function curve represent?

Answer 3

It relates work (volume pumped) to Atrial pressure (Preload)

Question 4

What is the effect when preload is increased?

Answer 4

1. INCREASED LVEDV
2. NO CHANGE LVESP & LVESV
3. INCREASE SV

Question 5

True or False: Stroke Volume CAN increase if rate of cardiac filling STAYS the same.

Answer 5

False! Stroke Volume CANNOT increase unless the rate of cardiac filling also increases.

Question 6

Why do the sarcomeres of the heart stay at a suboptimal level under normal conditions?

Answer 6

So the heart can tolerate an increased amount of venous return which would allow for sarcomeres to stretch to optimal levels and INCREASE force of contraction without compromising cardiac function.

Question 7

What is the effect on LVESP and Stroke Volume with Increased Afterload, TPR, & MAP.

Answer 7

LVESP Increases

Stroke Volume Decreases

Question 8

What is Afterload?

Answer 8

aortic pressure, overall blood pressure, or total peripheral resistance.

Question 9

What is decompensated heart failure?

Answer 9

Normally CO is stable at a give pressure but when a certain pressure is reached where the heart cannot handle CO decreases.