Cardiac Cycle

Question 1

Assessment of Perfusion at the Bedside

Answer 1

Cold extremities indicate reduced perfusion

Poor Urine Output also indicates poor tissue perfusion

Question 2

Cardiac Output (CO)

Answer 2

CO is the amount of blood pumped by each ventricle in one minute
CO is the product of heart rate (HR) and stroke volume (SV)

Question 3

Ejection fraction (EF or LVEF)

Answer 3

measurement of ventricular systolic function

      - normal is 60%
      - echocardiogram
      - cardiac catheterization

Question 4

Preload

Answer 4

degree of stretch on the myocardial fibers at the onset of contraction (EDV)

Question 5

Afterload

Answer 5

the tension which the myocardium is required to develop during contraction OR the resistance which the heart muscle must overcome in order to eject the blood into the arteries (SVR)

Question 6

Inotropic state

Answer 6

degree of contractility of the myocardium

Question 7

Increase preload (EDV)

Answer 7

Increase SV and EF

Question 8

Increase in afterload

Answer 8

Reduce SV and EF

Decreased Afterload Increases SV

Question 9

Increase contractility

Answer 9

Increase SV and EF

Question 10

Frank Starling Law of the Heart

Answer 10

The more cardiac muscle is stretched within physiological limits, the more forcibly it will contract.
Rubber band analogy
Increasing volumes of blood in ventricles increase the stretch & thus the force generated by ventricular wall contraction.