Hypertension Flashcards Preview

Cardiopulmonary I > Hypertension > Flashcards

Flashcards in Hypertension Deck (25)
Loading flashcards...

When is flow to the systemic organs the highest

During systole (when the pressure reaches 120 mm Hg), except for the left ventricle


What is the definition of hypertension

Diastolic pressure more than 90 and systoic pressure more than 140


3 different causes of hypertension

An increase in CO, or TPR or both


2 types of hypertension

Primary hypertx: underlying cause is unknown, happens 95% of the cases

Secondary hypertx: the cause of increase in CO or TPR can be identified


What do the cardiac glycosides do

They block Na-K ATPase, this causes Na to be very high inside the cell activating Ca-Na pump which increases Ca levels inside the cell, increasing the inotropic state of the heart


What are the 2 possible reasons for primary hypertension

1. Abnormal function of Na-K pump, this causes increase in Ca intracellular levels

2. Microvascular dysfunction: decreased levels of NO and increased levels of endothealin 1

There's evidence that some people have elevated levels of ouabain which causes hypertension since ouabain is a cardiac glycoside


Trend of role of CO and TPR in hypertension with age


How does TPR increases with age

There are 2 major mechanisms:

1. Arteriolar hypertrophy in response to high blood pressure results and this causes the lumen of the arterioles to decrease

2. Compliance of the ventricles decreases which impairs dyastolic filling, an increase in inotropic state is hence required


What are the different forms of secondary hypertensions

1. Renal parechymal disease

2. Renovascular disease

3. Pheochromocytoma

4. Hypothyroidism

5. Hyperthyroidism 


Renal Parenchymal disease

Damage to the kidneys results in higher retention of Na and water.


What physical can you look for to check for renal parechymal disease



Renovascular hypertension

There is more renin released in this disease


What receptor stimulation causes renin secretion

Beta 1 stimulation



It is important to know that there is an increase in CO and TPR both


What happens to baroreflex in chronic hypertension

It adapts to the high blood pressure, this is called baroreceptor desensitivity. Curve shifts to the right, the rate of firing occurs at a higher arterial pressure. This means they will be opposing the effect drugs to treat this hypersensitivity.

Eventually the baroreceptor sensitivity recovers with drug treatment


How do you treat or avoid pheochromocytoma

Give alpha 1 and beta 1 antagonist before the surgery


Conn's Syndrome

There is an adrenal gland syndrome.

This also causes increase K secretion which causes hypokalemia.


Summary of hypertension


Effects of hypertension


How do you differentiate between diastolic and systolic function

Ejection fraction

It is important to know why this is the case

In systolic the heart cant beat strong enough and in diastolic the heart has reduced compliance so it doesnt fill far enough


ACE inhibitors and ARBs

ACE inhibitors end in -pril and ARBs end in -sartan


Effects of phenylephrine


What are the effects of phenylephrine on pulse pressure, taking into account the baroreflex

Pulse pressure is reduced since SV is reduced and afterload is also reduced


Effects of isoproterenol

Its a non selective beta agonist (acts on all 3)

Depends if its primarily beta 1 or beta 2 effect, the result will are similar


How do you differentiate if isoproterenol is stimulating beta 1 or beta 2 receptors?

They key is to look at the MAP first, Beta 1 causes an increase in MAP while beta 2 causes a decrease in MAP