HTN heather lecture Flashcards
What pathologies is HTN a major contributing factor?
CV disease, stroke, heart failure, renal failure
What determines blood pressure?
cardiac output and peripheral vascular resistance
What are the two categories of HTN?
Essential (Primary): Chronic elevation in blood pressure without evidence of other disease. Secondary: Elevation in blood pressure results from some other disorder (i.e. kidney disease)
How does age effect BP?
Systolic B/P continues a slow rate of increase throughout adult life. Diastolic B/P increases until age 50, then declines from the sixth decade onward.
What is isolated systolic HTN?
Elevated systolic pressure when diastolic is normal. most common form of hypertension in people older than age 50. Leads to LVH and left heart failure
What are complications of the elevated pulse pressure associated with HTN?
greater stretch of the arteries causes damage to the elastic elements of the vessel. Predisposes to aneurysms and development of intimal damage that leads to atherosclerosis.
What are causes of secondary HTN?
Renovascular: Renal artery stenosis and Fibromuscular dysplasia. Adrenal: Hyperaldosteronism and Pheochromocytoma
What drugs may interfere with antihypertensive agents or may cause HTN?
oral contraceptives, corticosteroids, NSAIDs, OTC cold remedies w/ephedrine
How does stenosis of the renal artery cause HTN?
Decrease in renal blood flow releases renin which increases angiotensin II. Angiotensin II stimulates the release of aldosterone resulting in Na+ and water retention and increased volume.
What are the two disease processes that cause renal artery stenosis?
Atherosclerotic renal artery disease: affects the proximal aspect of the renal artery, more common in older men, and bilateral. Fibromuscular dysplasia:
Fibrosis and aneurysm formation in the middle and distal renal arteries. More common in younger women
What are the clinical clues to renovascular HTN?
Sudden onset of HTN w/no family history, Drug resistant HTN, Abdominal bruit, Renal insufficiency, Worsening renal function after ACE inhibitor
What lab tests should be ordered if you suspect renovascular HTN?
Renal functions, BUN, Creatinine, Plasma renin levels, Angiography is definitive
Why is an ACE inhibitor contraindicated in tx of renal artery stenosis?
a kidney that is receiving an inadequate blood supply will activate the RAAS system. Therefore, a single dose of this ACE inhibitor will abruptly reduce renal function in the ischemic kidney
What are tx options for renovascular HTN?
balloon angioplasty or stent. may need antihypertensives for life
What are the causes of primary hyperaldosteronism?
women: unilateral adrenal adenoma. men: bilateral adrenal hyperplasia
How does hyperaldosteronism cause HTN?
Increased aldosterone stimulates excessive renal Na+ retention with resultant volume expansion and hypertension. Increased K+ excretion
What tests are ordered if you suspect primary hyperaldosteronism as cause of HTN?
Serum renin level (low), Urine aldosterone levels, Increased serum aldosterone level that does not suppress after saline-induced volume expansion, and CT to differentiate between adrenal adenomas and hyperplasia.
What is tx for primary hyperaldosteronism?
resect adrenal tumors. spironolactone (aldosterone antagonist) and additional diuretics for adrenal hyperplasia
What is aortic coarctation?
congential narrowing of the aorta (typically just distal to the left subclavian artery). leading to elevated pressures proximal to the coarctation and reduced pressures in trunk
What are the adult classifications of hypertensive BP?
Stage 1: systolic 140-159. diastolic 90-99.
Stage 2: systolic > 160. diastolic > 100.
If DBP less than 90 and SBP > 140…. Could be
isolated systolic hypertension
What are the adult classifications of normal adult BP and prehypertensive BP?
Normal: systolic <80
Prehypertensive: systolic 120-139 diastolic 80-89
Why do baroreceptors not react to elevated proximal pressures associated with aortic coartation?
reflex is blunted due to structural changes in the walls of vessels where the baroreceptors are located. Also become desensitized to chronic elevation in pressure and become “reset” to the higher pressure
What might be symptoms of HTN?
Occipital headaches, Blurred vision, Fatigue, Dizziness, Epistaxis, Dyspnea, Chest pain
What are symptoms of end organ damage with HTN?
CHF, Cardiovascular disease, Cerebrovascular disease, Uremia, Microalbuminemia, Aortic dissection
What are goal blood pressures in different health populations?
Normal: Less than 140/90. Diabetics: Less than 130/80. Renal disease: Less than 125/75
What initial lab screenings and diagnostics should be done for HTN?
CMP-assess renal fxn, glucose, electrolytes. Fasting lipids, U/A, CBC, EKG- LVH, prior MI, Echo -evidence of l. ventricular enlargement/failure
Describe the risk stratification groups for HTN
Group A: No factors, No target organ disease, CV disease. Group B: At least 1 risk factor or male, not including diabetes. No target organ disease or CV disease. Group C: Target organ disease, clinical CV disease or diabetes w/ or w/o risk factors
What lifestyle changes should be made for HTN?
Exercise at least 40 minutes/day. Maintain normal weight. Reduce salt intake. Increase potassium intake. DASH diet. Limit alcohol consumption. Stop smoking. Sleep.
When should a patient be diagnosed as hypertensive?
In the absence of end-organ damage, BP is persistently elevated after three to six visits over a several month period.
When should antihypertensive therapy be initiated?
if the systolic pressure is persistently > 140 and/or the diastolic pressure is persistently > 90 in the office and at home despite attempted nonpharmacologic therapy
How would you treat an urgent hypertensive crisis?
Captopril (Capoten) quick onset (50mg every 1-2hours). Amlodipine also used (2.5-5mg every 2 hours). Clonidine
How would you treat a hypertensive emergency?
Admit to hospital. Nitroprusside: minute to minute control with rate of 0.25-8mcg/kg/min. Watch for cyanide toxicity. Nitroglycerin: 5-100mcg/min. Tolerance after 24-48 hours. Labetalol, Hydralazine also IV alternatives.
What is a hypertensive crisis?
A sudden increase in blood pressure potentially associated with end organ damage. Urgent: No apparent end organ damage. Emergency: End-organ damage apparent or suspected
What are special minority considerations with HTN?
BP control lowest in Hispanic Americans and American Indians. African Americans have increased prevalence of HTN, in part due to resistance to BB, ACEI or ARB when used alone compared to diuretics or CCBs.
