6. Hypertension Flashcards
the morbidity/mortality of HTN is more based on systolic or diastolic pressure?
systolic
what happens to the risk of CV disease each time systolic pressure rises by 20 mmHg?
doubles
systolic BP of 120-139 or diastolic of 80-89 = labeled how?
prehypertensive
normal systolic and diastolic values?
<80
HTN is the major health problem of what group of americans?
African Americans
what is the formula for BP? BP = what?
CO x TPR
control of BP is function of what 2 major systems?
sympathetic, and RAAS
juxtaglomerular cells produce renin under what 3 circumstances?
- decr stretch in wall due to decr systemic pressure or renal artery stenosis
- reduced Na concentration in distal tubule (sign of hypovolemia)
- Beta receptor stimulation
what constricts the efferent arterioles?
Angiotensin II
Angiotensin II stimulates the adrenal gland to release what?
aldosterone (contributes to hypertension through sodium retention)
what are the 3 general hemodynamic patterns causing hypertension?
- overall increased BV
- incr CO
- incr peripheral vascular tone
incr total blood vol is associated with high or low renin?
low
appropriate therapy for HTN due to incr BV?
diuretics
possible specific causes of HTN due to incr blood volume?
- primary hyperaldosteronism
- excessive salt intake
- renal disease with salt retention
- Cushing’s disease
possible specific causes of HTN due to incr CO?
- hyperthyroid (cardiac B1 stimulation)
- hyperkinetic heart syndrome?
appropriate therapy for HTN due to incr CO?
beta-blockers
possible specific causes of HTN due to incr peripheral resistance?
- renovascular HTN
- hyperthyroid (catecholamine excess)
- hypothyroid (decr Beta2 receptors in arterioles)
- malignant HTN (late phase of essential HTN)
incr peripheral resistance is associated with high or low renin?
high
appropriate therapy for HTN due to incr TPR?
vasodilators
what needs to be done in order to diagnose essential/primary hypertension?
rule OUT secondary HTN.
3 causes of secondary HTN?
- primary hyperaldosteronism
- pheochromocytoma
- renal artery stenosis (renovascular HTN)
what is the cause of primary hyperaldosteronism?
hyperplasia or adenoma of adrenal cortex/zona glomerulosa
how is primary hyperaldosteronism diagnosed?
low renin and incr aldosterone, along with low K (aldosterone is K wasting and Na sparing)
what does hyperaldosteronism cause (at the level of the kidney)?
incr sodium retention, incr potassium excretion. –> hypokalemia and metabolic acidosis
Pheochromocytoma: where do the tumors occur?
tumors can be found in a variety of locations but the main site is adrenal medulla.
what are we currently using as pressures to define a disease state of HTN?
140/90
the prevalance of HTN increases with what three things?
- age
- Af-Americans
- reduced education levels (HTN lowers with education level)
what is the characteristic pathology of pheochromocytoma?
pts will have intermittent spells of HTN with symptoms associated with incr catecholamines which they are excreting. they may secrete NE or Epi or both.
WTF are catecholamines?
dopamine, Norepi, epinephrine. sympathetic response neurotransmitters released by the adrenal glands
appropriate therapy for HTN due to pheochromocytoma?
surgery. will locate tumor via CT after finding metabolites in urine or serum.
Etiology of renal artery stenosis, and what popn they are most common in?
atherosclerosis: older men
fibromuscular hyperplasia: younger women
why does BP increase as a result of Renal artery stenosis?
fall in afferent arteriola pressure, jux apparatus releases renin, initiating response by renan-antiogensin system. BP rises are a result of increased AtII and aldosterone.
why might a pt have hypokalemia due to excess aldosterone secr?
aldosterone is K wasting
how might you dx renal artery stenosis?
sample blood from each renal vein and see which one is excreting more renin
what is coarctation of the aorta?
rare congenital lesion in which the proximal aorta is narrowed, resulting in diminished perfusion of the lower half of the body.
what BP pattern can you expect to see in coarctation of the aorta?
BP low in the legs and high in the arms.