Hypertension pathophysiology Flashcards
Primary hypertension etiology? can it be cured?
Polygenetic HTN (more common than monogenetic)
- genetic defects related to sodium imbalance, NO release, aldosterone excretion, angiotensinogen physiology
most patients
- cannot cure but can control
- population studies guide choice of therapy (ex. stroke with black people, europeans CHD)
Secondary hypertension etiology? can it be cured?
Could be disease, drug, combo
Technically “yes”
Which drugs are secondary causes for HTN
- Alcohol/Ethanol (excessive)
- NSAIDs
- cyclosporine, tacrolimus
- COCs
- Corticosteroids
- Salt (high sodium intake)
- SSRIs/SNRIs/MAOIs
- Licorice root/ephedra alkaloids/St. John’s Wort
- Stimulants (cocaine, nicotine)
- Sympathomimetic decongestants
What disease can cause secondary HTN
- Chronic kidney disease
- Cushing’s syndrome
- Obstructive sleep apnea
- Parathyroid disease
- Pheochromocytoma
- Primary aldosteronism
- Renovascular disease
- Thyroid disease
What are the studies for black patients?
ACEi believed to be less effective for black patients
- not first line for black patients
Systolic BP
What occurs?
What is it determined by?
Equation?
When heart is contracting
- determined by Cardiac output CO
- CO = stroke volume x Heart rate
Dystolic BP
What occurs?
What is it determined by?
Heart is relaxing
- determined by total peripheral resistance
What is mean arterial pressure?
When is it used?
Equation?
MAP: 1/3 of SBP and 2/3 of DBP
- body spends more time in diastole
Used in hypertensive emergency
What is pulse pressure a measure of?
Equation?
Used for?
Directly correlated to?
Measures arterial wall tension
SBP - DBP
- used for isolated systolic HTN
- Directly correlated to CV morbidity/mortality
What is total peripheral resistance determined by? (2)
Functional constriction
Structural vascular hypertrophy
What is blood pressure the product of?
increase cardiac output and increased total peripheral resistance
what are causes of increased cardiac output
- increased cardiac preload
- increased fluid volume (from excess sodium/renal sodium retention)
- Venous constriction
- Excess stimulation of the renin-angiotensin-aldosterone system RAAS
- Sympathetic nervous system overactivity
what are causes of increased peripheral resistance
- Functional vascular constriction
- Excess stimulation
- SNS overactivity
- Excess stimulation of RAAS
- genetic alterions
- structural hypertrophy
- hyperinsulinemia resulting from metabolic syndrome
- endothelial derived factors
When is BP the lowest?
When does it rise sharply?
When is the highest BP?
When is BP increased acutely?
When is BP the lowest?
- during sleep
When does it rise sharply?
- few hours prior to awakening
When is the highest BP?
- midmorning
When is BP increased acutely?
- during physical activity or emotional stress
Define isolated systolic hypertension. What does it result from?
SBP value elevated and DBP are not <90 and <80
- result from changes in the arterial vasculature consistent with aging (decrease the compliance of arterial wall due to both structural and functional changes)
What is the most important regulator of BP
Renin-angiotensin-aldosterone system RAAS
How is BP detected?
Located in the afferent arterioles in the baroreceptor sensing device of the kidney
Which intra-renal factors is renin regulated by?
- renal perfusion pressure
- level of catecholamines
- angiotensin II
Which extra-renal factors is renin regulated by?
- level of sodium
- chloride
- potassium
What other things do the RAAS regulate?
- Na
- K
- blood volume
- vascular tone
- SNS
What does upregulation of RAAS do to BP?
Increase BP
What natriuretic hormone do?
Inhibits Na/K-ATPase
- interferes with Na transport
What does an increased NH cause?
MORE NH should reduce Na and water in the system
Since NH also interferes with Na transport out of smooth muscle cells
- more NG causes INC intracellular Na + Ca –> Inc vascular tone
How is hyperinsulinemia caused?
Combo of multiple CV insulin resistance and metabolic syndrome
