Hypertension Flashcards
Which organ is essential in the maintenance of chronic hypertensive states?
Kidney
Bp determined by
CO*SVR
CO determined by
HR*SV
Pressure natriuresis
Increasing BP causes excretion of Na and H2O due to baroreceptors at kidney. Then BP decreases
Hypertension effect of pressure natriuresis
Respnse in blunted. Normal intake of sodium doesn’t increase output
Where does pressure natriuresis occur?
In the proximal nephron
How does hypertension affect the baroreceptors in the carotid sinus?
Stimulates them (this is acute regulation), to cause decreased cardiac output and vasodilation. These effects cause blood pressure reduction
Essential hypertension
Essential hypertension is hypertension without an identifiable cause. Its the most common form of hypertension (90%) and is a diagnosis of exclusion. Multifactorial cause likely.
Potential causes of essential hypertension
Genetics- hereditary component exists.
Systemic abnormalities – cardiac sympathetic overactivity, abnormal regulation of vascular tone
Renal abnormalities– excess sodium/water retention.
What is more common at what stage in life?
Isolated diastolic hypertension or isolated systolic hypertension?
Isolated diastolic hypertension common earlier in life. Becomes less common because arteries harden due to increased pressure. Loss of elastic recoil. So isolated systolic hypertension becomes more common.
Secondary hypertension
Presence of hypertension in the setting of clear structural/hormonal cause.
Clues of secondary hypertension
Young age (<20 years)
New onset over 50.
More severe with rapid onset
Causes of secondary hypertension
Chronic kidney disease (impaired ability of kidney to excrete sodium and water so rise in blood volume, elevation of CO.)
Renovascular (Renal artery stenosis due to atherosclerosis or fibromuscular dysplasia (young women)) Causes reduced renal blood flow and as a result, activation of the RAAS.
Aortic Coarctation – congenital narrowing of the aorta causes reduced blood flow to kidney
Hypertension with high creatinine or abnormal urinalysis suggestive of
Secondary hypertension due to chronic kidney disease
Hypertension with abdominal bruit, unexplained hypokalemia suggestive of
Renal artery stenosis. Treat with ace inhibitors