Treatment of HTN

Question 1

Resistance is influenced by ___ (indirectly) and ____ (directly)

Answer 1

Blood volume- indirect

Vessel diameter- direct

Question 2

__% of all American adults have HTN

__% of adults over 65 have HTN

Answer 2

28%

60%

Question 3

Blood pressure refers to

Answer 3

The force exerted by the blood upon walls of the blood vessels or chambers of the heart

Question 4

HTN develops when

Answer 4

Blood volume is too high for the space available inside blood vessels.

Question 5

What can cause an increase in blood pressure?

Answer 5

Increased CO or increased peripheral resistance

Question 6

HTN

Answer 6

Sustained systolic BP of greater than 140 mmHg or sustained diastolic BP of greater than 90mmHg

Question 7

4 classifications of blood pressure

Answer 7

Normal: less than 120/80
Pre-Hypertensive: 120-139/80-89
Stage 1: 140-159/90-99
Stage II: Greater than 160/100

Question 8

Which populations have higher incidence of HTN

Answer 8

AA, middle age men, older
Family history increases risk

Environmental factors further predispose a person: Stress, high intake of sodium, smoking.

Question 9

Why is arterial BP regulated within such a narrow range?

Answer 9

To provide perfusion of tissues without causing damage to vascular system. Especially arterial endothelium.

Question 10

BP is directly related to

Answer 10

CO and peripheral resistance

Question 11

Cardiac output is controlled by

Answer 11

HR, contractility, and filling pressure (Which is controlled by blood volume and venous tone)

Question 12

Peripheral resistance is controlled by

Answer 12

Arteriolar tone

Question 13

CO and peripheral resistance are controlled by which two overlapping systems

Answer 13

Baroreflexes and RAAS system

Question 14

Baroreceptors act by:

Answer 14

Act by changing the activity of the sympathetic nervous system. Rapid, moment to moment control.

A fall in BP causes baroreceptors to send fewer impulses to cardiovascular centers in the spinal cord. Reflex response of increased sympathetic and decreased parasympathetic output. (results in vasoconstriction and increased CO)

Question 15

RAAS system acts by:

Answer 15

Kidney provides long term control of BP by altering blood volume.
Baroreceptors in the kidney respond to reduced arterial pressure (AND to sympathetic stimulation of B1 receptors)
Kidney responds by increasing the release of renin.

Low sodium intake or greater sodium loss also results in release of renin

Question 16

Which 3 stimuli trigger renin release

Answer 16

1. Baroreceptors in the kidney notice reduced arterial pressure
2. B1 stimulation thru the sympathetic system
3. Decreased sodium intake or increased sodium release

Question 17

RAAS flow starting with angiotensinogen

Answer 17

Angiotensinogen circulates in the blood and is converted to angiotensin I by renin, which is released by the kidney. Angiotensin I is biologically inactive. Angiotensin I is converted to Angiotensin II by ACE enzyme. Angiotensin II is active and is a potent vasoconstrictor, stimulates aldosterone secretion, increases peripheral resistance, decreases capacitance. Also may cause cardiac hypertrophy (myocardial fibrosis and apoptosis)

Question 18

Role of aldosterone

Answer 18

Released by the adrenal gland. Stimulated release by angiotensin II.
Results in the reabsorption of salt from the kidney, resulting in the reabsorption of water. This will increase the volume of blood, which increases BP.

Question 19

Effects angiotensin II has on the body

Answer 19

Potent vasoconstrictor: Increase peripheral resistance, decrease capacitance.
Stimulates release of aldosterone.
May cause cardiac hypertrophy: Myocardial fibrosis and apoptosis

Question 20

Most antihypertensives lower BP by

Answer 20

reducing cardiac output and/or decreasing peripheral resistance. Some do a little bit of both.

Question 21

Treatment strategies

Answer 21

Tailored to each patient
Usually use a combo- want to use different MOA
Must look at different factors including age, race, side effects, disease.

Question 22

Tx example:

Vasodilator. Then add BB then add diuretic

Answer 22

Vasodilator: Will reduce peripheral resistance, but will result in reflex tachycardia and salt/water retention.
Add BB to decrease reflex tachycardia.
Add diuretic to decrease reflex salt/water retention.

Any of these 3 could work on their own, but some pts may need combos.

Question 23

Angiotensin agents work to

Answer 23

Reduce peripheral resistance and blood volume.

Bc angiotensin causes constriction (increase peripheral resistance) and aldosterone release (increase blood volume)

Question 24

Diuretic agents work to

Answer 24

Decrease sodium levels and blood volume.

Question 25

Sympathetoplegic agents work to

Answer 25

Reduce peripheral resistance and decrease CO

Question 26

Direct vasodilators work to

Answer 26

Decrease peripheral reisistance

Question 27

Beta blockers work to

Answer 27

Decrease renin release, contractility, and HR

Question 28

Most common reason for therapy failure

Answer 28

Lack of patient compliance
The pt is usually asymptomatic.
Pt may feel worse as BP is decreasing

Question 29

Resistant hypertension

Answer 29

High BP that does not respond to tx. Remains high despite 3 drug regimen.
Most commonly use to:
Poor compliance
Excessive alcohol drinking.
Use of sympathomimetics, NSAIDs, or antidepressants.
Insufficient dose
Using multiple drugs with same MOA

Question 30

RAAS system monitors

Answer 30

Na, K, Vascular volume, BP