Hemodynamics

Question 1

CO equation

Answer 1

CO = SV x HR

Question 2

BP equation

Answer 2

BP = SVR x CO

Question 3

Stroke volume is…

Answer 3

The amount of blood ejected

The EDV - ESV

Question 4

Systolic function

Answer 4

Ability of the ventricular myocardium to empty blood from the cardiac chamber

Question 5

Diastolic function

Answer 5

Ability of the ventricular myocardium to relax and fill the cardiac chamber with blood

Question 6

Ejection fraction

Answer 6

The most common objective assessment of systolic function
Stroke volume/EDV
Normal is 55-65%

Question 7

3 determinants of stroke volume

Answer 7

Preload
Afterload
Contractility

Question 8

Preload definition

Answer 8

The ventricular wall tension at the end of diastole

Approximated by LV EDV

Question 9

Frank-Starling curve

Answer 9

The longer the cardiac muscle fiber prior to contraction, the stronger the force of contraction
(to a point)

Question 10

Effect on SV

1. Increasing the preload
2. Increasing the afterload
3. Increasing contractility

Answer 10

1. Increases SV
2. Decreases the SV
3. Increases the Sv

Question 11

Law of LaPlace

Answer 11

To do with afterload

Wall stress = pressure x radius / 2 x wall thickness

Question 12

Afterload definition

Answer 12

The ventricular wall stress encountered during contraction that must be overcome in order to eject blood
Approximated by the systolic arterial pressure

Question 13

3 Hemodynamic responses to exercise

Answer 13

Increase in preload
Increase in afterload
Increase in contractility

Question 14

2 types of cardiac hypertrophy

Answer 14

Concentric

Eccentric

Question 15

Concentric hypertrophy

Answer 15

Increase in myocardial wall thickness secondary to chronic pressure overload
Fibers are added in parallel

Question 16

Eccentric hypertrophy

Answer 16

Increase in cardiac chamber radius secondary to chronic volume overload
Same as dilation
Fibers are added in series

Question 17

Problems with concentric hypertrophy

Answer 17

Increase in myocardial oxygen consumption
Increase in myocardial workload
Decreased ventricular compliance
Decrease in chamber cavity size
Negative geometric remodelling
Decrease in SV
Impaired systolic dysfunction

Question 18

Problems with eccentric hypertrophy

Answer 18

Increase in myocardial oxygen consumption
Increase in myocardial workload
Decreased ventricular compliance
Negative geometric remodelling
Impaired systolic dysfunction