Hemodynamics: The Basis Of CV Damage

Question 1

What factors affect the forward wave? 3

Answer 1

1) Stroke volume
2) Aortic impedance
3) Aortic stiffness

Question 2

What factors affect the backward wave? 3

Answer 2

1) Forward wave
2) Vascular resistance
3) Medium sized artery changes

Question 3

What is blood pressure? 2

Answer 3

BP is the complex interplay between cardiac function and arterial load (opposition to flow).

Question 4

What are the components of arterial load?

Answer 4

Arterial load can be understood in terms of a:

1) Resistive component: systemic vascular resistance
2) Pulsatile component: total arterial compliance, characteristic impedance of the aorta and the indices of wave reflections

Question 5

Is effective arterial elastance (Ea) an effective measure of arterial load?

Answer 5

No, it has been shown that Ea depends almost entirely on HR and SVR and thus is insensitive to the pulsatile component of arterial load.

Question 6

What is reflection magnitude?

Answer 6

It is the ratio of backward wave to forward wave. RM = pb/pf

Question 7

What is the primary factor that determine SVR? (Resistive load)

Answer 7

The resistive load is largely determined by the arterioles and is the primary determinant of absolute level of overall wall stress experienced by the myocyte during ejection.

Question 8

What does proximal aortic impedance Zc define?

Answer 8

Zc defines the early pressure-flow relationship and is an important determinant of early ventricular afterload and PP>

Question 9

Is the value of Pb equal to one reflected wave?

Answer 9

No, it represents the summatation of myriad reflected waves that are generated as the forward wave propagates throughout the arterial system.

Question 10

Explain the flaw in using SBP as the primary guide to prognosis and therapy.

Answer 10

SBP provides an aggregate measure of mean and pulsatile pressure and thus may potentially overlook the components of each. Therefore, SBP does not establish if there is an abnormality in mean or pulsatile load

Question 11

How does the backward wave contribute to CVD risk?

Answer 11

The effect of the backward wave is determined by timing. When the backward arrives during diastole it has positive effects. However, when it arrives during systole, it increases lv afterload and has been shown to adversely effect LV remodeling, as well as SBP and DBP