Hypertension Flashcards
Primary determinant of arterial pressure over the long term
Intravascular volume
Modulator of BP on a minute-to-minute basis, i.e. postural changes, stress, changes in blood volume
Baroreceptor reflex arc
NaCl-dependent hypertension
Increase in BP secondary to decreased renal Na excretion
3 primary stimuli for renin secretion
- Decreased NaCl transport in the thick ascending loop of Henle via macula densa mechanism
- Decreased pressure or stretch within the renal afferent arteriole via baroreceptor mechanism
- Sympathetic nervous system stimulation of renin-secreting cells via beta 1 receptors
Effects of angiotensin II
- Vasoconstriction
- Release of catecholamines
- Aldosterone secretion
- Stimulates vascular smooth muscle cell and myocyte growth
Most common cause of death in hypertensive patients
Heart disease
Most accurate assessment of diastolic function
Cardiac catheterization
Strongest risk factor for stroke
Hypertension
Most common etiology of secondary hypertension
Primary renal disease
Renal lesion in malignant hypertension
Fibrinoid necrosis of the afferent arterioles
Circadian pattern of BP
Higher in early AM
Nighttime BP are 10-20% lower than daytime BP
Criteria for diagnosis of hypertension based on home BP and/or 24h-ambulatory blood pressure measurements
Awake: >/= 135/85
Asleep: >/= 120/75
_____ peripheral vascular resistance and _____ cardiac output in majority of patients with established hypertension
Increased peripheral vascular resistance and normal/decreased cardiac output
Form of hypertension among high-renin patients
Vasoconstrictor form of hypertension
Form of hypertension among low-renin patients
Volume-dependent form of hypertension
Indicative of primary renal disease causing hypertension
Proteinuria > 1000mg/day and active urine sediment
Gold standard for evaluation of renal artery stenosis
Contrast arteriography
Simplest screening test for primary hyperaldosteronism
Measurement of serum potassium - hypertensive patients with unprovoked hypokalemia
Useful screening test for primary hyperaldosteronism
Ratio of plasma aldosterone to plasma renin activity > 30:1 + plasma aldosterone concentration of >555pmol/l (>20ng/dl)
Confirmatory test for primary hyperaldosteronism
Inability to suppress plasma aldosterone to <10ng/dl after IV infusion of 2L of isotonic saline over 4h
Treatment for primary hyperaldosteronism
Low dose glucocorticoids, aldosterone antagonists
Best screening test for Cushing’s syndrome
24h urine test for cortisol and creatinine
Low dose dexamethasone challenge
Definitive treatment for pheochromocytoma
Surgical excision
BP control medication for pheochromocytoma
Alpha blockers first then add beta blockers if persistent