Lecture 26 - Hypertension II

Question 1

What is primary hypertension?

Answer 1

Hypertension due to unknown cause - idiopathic essential

Question 2

What is secondary hypertension?

Answer 2

Hypertension due to a specific cause?

Question 3

What does salt retention in kidney do to blood volume?

Answer 3

Increases blood volume

Question 4

How does an increase in blood volume cause an increase in TPR?

Answer 4

Increase in blood volume autoregulation result in arteriolar vasoconstriction arterial compliance decrease - increase in total peripheral resistance (TPR)

Question 5

What does the sympathetic activation of the arterioles cause?

Answer 5

Arteriolar vasocontraction which decreases arterial compliance

Question 6

How does a decrease in arterial compliance cause an increase in blood volume?

Answer 6

Arterial compliance decrease - increase TPR less blood flow to kidney - release vasoactive substances and salt retention increase in blood volume

Question 7

What is the effect of moderate exercise on sympathetic activity?

Answer 7

Balanced increase in sympathetic activity
CO (HR⇧ x SV⇧) x TPR ⇩ = MAP⬄

Question 8

What is the effect of moderate exercise on sympathetic activity?

Answer 8

Hypertension - systemic increase in overall sympathetic activity
CO (HR⇧ x SV⇧) x TPR ⇧ = MAP⇧

Question 9

The cause of primary hypertension is thought to be due to:
A. an increase in arterial compliance and/or an increase in arterial blood volume.
B. an increase in arterial compliance and/or a decrease in arterial blood volume.
C. a decrease in arterial compliance and/or an increase in arterial blood volume.
D. a decrease in arterial compliance and/or a decrease in arterial blood volume.

Answer 9

C. a decrease in arterial compliance and/or an increase in arterial blood volume.

Question 10

What are the consequences of hypertension?

Answer 10

• Kidney disease
• Development of Atherosclerosis – Stroke
• Atrial Fibrillation
• Myocardial Infarction / Coronary artery disease
• Cardiac Remodelling (Hypertrophy - Heart Failure)

Question 11

Describe Cardiac Remodelling - Afterload

Answer 11

Increases workload (afterload) of the heart
- Stiffer tube (aorta) to eject blood into
- Faster returning reflected pulse wave
Higher resistance to the output
Remodelling – cellular and organ

Question 12

What increases in cardiomyocyte hypertrophy?

Answer 12

Increase in number of sarcomeres in the cardiomyocytes (size)
NOT in number of cardiomyocytes NOR the size of the sarcomeres!

Question 13

Why does hypertension cause fibrosis in heart?

Answer 13

Increased load triggers formation of more extracellular matrix (ECM), fibrosis
Increase in collagen type III followed by type I

Question 14

What makes up the ECM?

Answer 14

Collagen type I + III
Elastin
Proteoglycans
Laminin
Fibronectin

Question 15

What are the types of pathological caridac remodelling (with fibrosis)?

Answer 15

Hypertension
Hypertrophic cardiomyopathy
Dilated cardiomyopathy/heart failure - Final outcome in all cases

Question 16

What are the types of physiological caridac remodelling (without fibrosis)?

Answer 16

Endurance athlete - thicker LV walls + LV dilation
Strength athlete - thicker LV wall + mild LV dilation
Combination athlete - Gross thickening of LV walls, LV dilation

Question 17

What is the cardiac remodelling in hypertension?

Answer 17

Thickening of LV walls, no dilation in early stages of disease
- Pressure overload/concentric

Question 18

What is the cardiac remodelling in dilated cardiomyopathy/heart failure?

Answer 18

Thinning of LV walls
Significant LV dilation
- Volume overload/eccentric (valve)

Question 19

What is the cardiac remodelling in hypertrophic cardiomyopathy?

Answer 19

Gross thickening of LV walls
No dilation/decrease in LV chamber
- predominantly genetic mutations

Question 20

What type of remodelling occurs during hypertension?

Answer 20

Concentric

Question 21

What type of remodelling occurs with age?

Answer 21

Concentric

Question 22

What type of remodelling occurs between the sexes?

Answer 22

Male/Female
Eccentric/Concentric

Question 23

What type of remodelling occurs in coronary artery disease?

Answer 23

Concentric

Question 24

What type of remodelling occurs in valve leaks?

Answer 24

Eccentric

Question 25

What type of remodelling occurs in obesity?

Answer 25

Eccentric / concentric

Question 26

What type of remodelling occurs in diabetes?

Answer 26

Concentric/eccentric

Question 27

What type of remodelling occurs in familiar dilated cardiomyopathy?

Answer 27

Eccentric

Question 28

What is the effect of systemic hypertension on the RV?

Answer 28

Early stage - no effect on RV
Late stage - hypertrophied RV

Question 29

What does the systemic circulating factors do in hypertension?

Answer 29

Increase LV filling pressure which translates into increasing pulmonary circulation
Hypertrophied LV interacts with the RV

Question 30

In the early stages of hypertension the right ventricle does not remodel BECAUSE the development of atherosclerosis in the aorta increases afterload.
A. Both statements are correct and causally related.
B. Both statements are correct and NOT causally related.
C. Only the first statement is correct and the second statement is incorrect.
D. Only the second statement is correct and the first statement is incorrect.
E. Both statements are incorrect.

Answer 30

B. Both statements are correct and NOT causally related.

Question 31

What are alternative treatments of hypertension?

Answer 31

Renal denervation
Carotid body denervation
Baroreceptor denervation