Hypertensive Cardiovasular disease (Duval)

Question 1

Definition of Hypertension

Answer 1

Sustained blood pressure elevation

- Diastolic greater than 90 mmHg
- Systolic greater than 140 mmHg

Question 2

What are 5 major risks associated with Hypertension

Answer 2

1) Coronary artery disease
2) Cerebrovascular accident (stroke) - ischemic
3) CHF
4) Aortic dissection
5) Renal failure

Question 3

Hypertension affects _____ % of the population

Answer 3

25%

Question 4

What are groups at higher risk for hypertension?

Answer 4

Blacks more than whites

Prevalence increases with age

Question 5

What the two major classifications of hypertension? (what are the % who get each)

Answer 5

Primary “idiopathic’ essential HTN (90-95%)

Secondary (HTN) (5-10%)

Question 6

What are some causes of Secondary HTN

Answer 6

1) renal disease
2) Renal artery stenosis (usually from a plaque)
3) Adrenal diseases (aldosteronism, Cushing’s, tumors)
4) Neurological diseases
5) Other

Question 7

Benign vs. Malignant HTN

Answer 7

Benign - Has a modest stable elevation in BP, usually can have a long life
Malignant (5%) - Has a rapidly rising BP and severe HTN . Can lead to renal failure, renal hemorrhages and death within 2 years

Question 8

What is the equation for blood pressure regulation?

Answer 8

BP = CO + PVR (Peripheral vascular resistance). So here Cardiac output and PVR are proportional to BP

Question 9

What are the main factors of Cardiac output

Answer 9

Blood flow/ Blood volume and that depends a lot on serum sodium.

Question 10

What are the main factors of Peripheral vascular resistance?

Answer 10

It depends on the arteriolar luminal diameter which is under the control of vasoconstrictors and vasodilators

Question 11

Name 5 vasoconstrictors in the body.

Answer 11

1) Angiotensin II
2) Catecholamines
3) Thromboxane
4) Leukotrienes
5) Endothelin

Question 12

Name 6 vasodilators in the body…

Answer 12

1) Kinins
2) Prostaglandins
3) Nitric Oxide
4) Lactic Acid
5) H+ ion
6) Adenosine

Question 13

What is the Glomerular Filtration Rate?

Answer 13

The rate at which blood is filtered in the glomeruli in the kidneys. (a measure of kidney function

Question 14

Describe blood pressure regulation in the kidney

Answer 14

Blood flow comes in thru the renal artery and filtered in the glomeruli (GFR). When GFR falls, the kidney senses it. It secretes renin that converts angiotensinogen floating in the blood to Angiotensin I, that’s then acted on by Angiotensin Converting enzyme (ACE…produced by the lung and other tissues) and makes it to Angiotensin II. That raises PVR by causing vasoconstriction and triggers aldosterone that tells kidney to absorb more Na+ and H2O. BP goes up.

Question 15

Where does the kidney especially detect changes in the GFR rate

Answer 15

The JGA (Juxtaglomerular apparatus )

Question 16

How does the heart regulate BP

Answer 16

Reacts from expansion. If you have high blood volume and distention of the atrium of the heart. THe heart then secretes Atrial Natrioretic Factor (ANF). That causes the kidney to absorb less Na+ and H2O and BP goes down

Question 17

Describe the pathogenesis of (secondary) Hypertension d/t Renal Artery Stenosis

Answer 17

An AS plaque develops in the renal artery, that results in less profusion and volume. That drops GFR and kidneys secrete renin and triggers Angiotensin/aldosterone response. That inappropriately leads to vasoconstriction and increase Na+ and H20 absorption in kidney. Kidney thinks BP is low but BP is going up d/t increased absorption

Question 18

Why do we know that there is genetic factors that contribute to essential HTN

Answer 18

Twin studies, family aggregation. Adoption studies, induced in inbreeding animals, single gene defects identified and most common, cumulative effects of different alleles in different genes

Question 19

What are some single gene defects that can lead to Essential HTN

Answer 19

1) Defects in aldosterone metabolism
- Aldosterone synthase enzyme
- 11 Beta hydroxylase
2) Liddle’s syndrome - Mutations in epithelial Na+ channel proteins that cause an increased response to aldosterone.

Question 20

What are two ways that PVR can be acquired

Answer 20

1) Functional vasoconstriction - Increased release of v/c agents
2) Structural agents - Smooth muscle hypertrophy/hyperplasia

Question 21

Describe the current hypothesis around the cause(s) of HTN

Answer 21

Genetic/environmental influences cause defects in cell cycle genes which stimulate smooth muscle cell growth, resulting in vascular wall thickening, increased vascular tone and vasoconstriction

Question 22

Where you may see Hyaline Arteriosclerosis?

Answer 22

In aging individuals, benign nephrosclerosis (benign HTN) and diabetes

Question 23

What is the morphology of Hyaline Arteriosclerosis?

Answer 23

It presents as a pink homogeneous hyaline thickening. It’s a ‘smudgy material’ that causes the thickening of the vessel blood wall

Question 24

What is Benign Nephrosclerosis?

Answer 24

Its a Hyaline Arteriosclerosis in the kidney, where A thickening of the blood vessel wall via this pink smudgy material narrows blood vessels and you get smooth muscle hyperplasia. That causes scaring of the glomeruli (glomeruli sclerosis). It gives the kidney a granular outside appearance

Question 25

What do you see microscopically in Hyaline Arteriosclerosis?

Answer 25

Thickened walls of vessels and narrow openings

Question 26

Where do you see Hyperplastic Arteriosclerosis?

Answer 26

You see it with malignant hypertension (with a diastolic reading over 120)

Question 27

How will Hyperplastic Arteriosclerosis present?

Answer 27

You’ll see it in the kidney, gall bladder, periadrenal fat. You’ll see ‘onion skinning’ smooth muscle hypertrophy or hyperplasia, fibrinoid deposition

Question 28

What do you see microscopically in Hyperplastic Arteriosclerosis?

Answer 28

Many layers of smooth muscle cells surrounding a small lumen. Sometimes you may see a layer of necrosis.

Question 29

What is Marfan’s syndrome?

Answer 29

It’s a genetic disorder that involved the fibrilin gene (it encodes a protein in elastic connective tissue… like the aorta). About 70-90 percent have HTN. They are at risk for aortic dissection and generally have a thickening of the arterial wall (cystic medial dissection

Question 30

What is the outside presentation of Marfan’s syndrome

Answer 30

They are generally tall and lanky, chest wall deformities an long double jointed fingers

Question 31

Define Hypertensive Heart disease

Answer 31

Left Ventricular Hypertrophy in an individual with HTN without any other reasons of hypertrophy (Aortic stenosis, HCMP)

Question 32

What is the pathogenesis of Hypertensive Heart disease?

Answer 32

A sustained pressure load due to HTN acts as a stimulus causing changes in gene expression in myosin, actin, etc. The end result is a thick left ventricle which has more metabolic requirements but you’re reducing the supply of these requirements (increased delivery distance) and a stiffer myocardium

Question 33

What can happen over time with Hypertensive Heart disease

Answer 33

It can lead to ischemic injury leading to CHF (50 percent last 5 years), MI and arrhythmias.

Question 34

What do you see in the heart with Hypertensive Heart disease?

Answer 34

Gross - An increased heart weight, larger circumference of left ventricle (due to wall thickness)
Microscopically - Hyperchoromatic boxcar nuclei and interstitial fibrosis.

Question 35

What are the clinical s/s of Hypertensive Heart disease?

Answer 35

None if you maintain a proper CO and in heart failure. If so then you can have CHF or angina, renal damage, stroke or sudden cardiac death.

Question 36

What tests diagnose Hypertensive Heart disease?

Answer 36

CXR, ECG, echocardiogram

Question 37

What is Cor Pulmonale

Answer 37

Its disease of the right heart due to pulmonary HTN can be due to pulmonary disease or pulmonary vascular disease (like a pulm. embolism). This is NOT a left or congenital heart problem.

Question 38

What are the two types of Cor Plumonale?

Answer 38

Acute - Usually due to a PE with acute Right ventricular failure, may be dilated or normal in size
Chronic - Usually due to chronic obstructive pulmonary disease. They will get chronic RVF that evolves over time. That will give long standing PHTN, increased weight and pulmonary artery athrosclerosis.

Question 39

How do you get RHF from LHF?

Answer 39

Left heart is failing as you’re not ejecting the blood, that increases congestion in pulmonary circulation and increases pulmonary edema that increases pulmonary resistance and that can lead to RHF and systemic venous congestion