Flashcards in Hypertension Deck (31)
Which organ is essential in the maintenance of chronic hypertensive states?
Bp determined by
CO determined by
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 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.
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
Hypertension with higher BP in arms than legs, or higher BP in right arm than left arm, and rib notching suggestive of
Endocrine causes of secondary hypertension
Primary aldosteronism (Conn Syndrome, decreases renin from negative feedback)
Secondary aldosteronism (renin secreting tumor)
Excess glucocorticoids (expand blood volume and stimulate RAAS)
How does pheochromocytoma present?
With paroxysms of palpitations/tachycardia/headaches
How does thyroid dysfunction cause hypertension
Both hyper and hypothyroid patients can develop HT
Hyper: Cardiac hyperactivity, increase in blood volume
Hypo: Diastolic hypertension, increase in PVR.
Some other causes of secondary hypertension
Cocaine, alcohol, cold remedies, EPO, oral contraceptives
Consequences of hypertension
Arterial damage -- smooth muscle hypertrophy, endothelial dysfunction, loss of elasticity.
Organ damage - brain, heart, aorta, kidney, retina.
Consequences of increasing BP 20/10?
CV disease risk doubles with each increment
Cardiac effects of hypertension
LV hypertrophy due to increased afterload. This leads to increased ventricular stiffness and diastolic dysfunction.
Systolic dysfunction due to hypertension and myocardial ischemia
Coronary artery disease- development of atherosclerosis which increases cardiac work and myocardial oxygen demand.
Most common form of heart failure in elderly?
Effect of hypertension on brain
Causes stroke! Both ischemic and hemorrhagic. Effective BP treatment has led to 50% reduction in stroke deaths
Effect of HTN on aorta?
Aneurysm of the abdominal aorta (can burst causing death)
Aortic dissection (can occur at ascending and descending aorta) intima tears
SBP >180 or DBP >110 without evidence of end-organ damage. Requires immediate evaluation but not admission to ED
BP >180 or DBP > 100 with signs/symptoms of end organ damage including headache/blurred vision (encephalopathy), SOB (pulmonary edema due to LV hypertrophy), papilledema/retinal exudate.
Immediate hospitalization with rapid control of BP.
Nonpharmacologic treatment for HTN
Weight reduction (each 10kg = 5-20 decrease in BP)
Decrease EtOH, stop smoking
Diuretics (best for mild-moderate HTN with normal renal function)
Beta Blockers -- reduce CO, reduce renin secretion
REDUCE MORTALITY after MI/CHF
Alpha 2 agonists - decrease sympathetic outflow
Alpha 1 antagonists - relax smooth muscle
CCB- reduce influx of calcium necessary for cardiac/vascular smooth muscle contraction
Direct vasodilators - relax smooth muscle cells
ACE inhibitors-- REDUCE MORTALITY
ARBs -- REDUCE MORTALITY.