42. Hypertension Flashcards
What is the formula for calculating BP?
What are systolic and diastolic BP?
What is:
a) grade 1 (mild) hypertension?
b) grade 2 (moderate) hypertension?
3) grade 3 (severe) hypertension?
BP = cardiac output x systemic vascular resistance
Systolic: max BP during ventricular contraction
DIastolic: min level of BP measured between contractions of the heart
NB: BLOOD PRESSURE IS LABILE
a) 140-159/90-99
b) 160-179/100-109
c) >=180/>=110
What is stage 1 hypertension?
What is stage 2 hypertension?
What is severe hypertension?
Clinic BP 140/90 or higher (and HBPM = 135/85 or more)
Clinic BP 160/100 or higher (and HBPM = 150/95 or more)
Clinic BP is 180/110 or higher
What is high normal BP (prehypertension)?
What is isolated systolic hypertension?
How is ISH treated?
130-139/85-89. Not a disease category. Should encourage lifestyle modification as risk of hypertension. Not candidates for drugs unless e.g. diabetes (goal <130/80).
>140/<90 i.e. systolic high, diastolic normal. Less serious than hypertension but more serious in elderly.
1st stage: lifestyle interventions - low Na+ and fruit + veg, physical activity, limited alcohol consumption. If lifestyle changes do not reduce systolic hypertension to safe level then use drugs.
What is hypotension?
What is postural (orthostatic) hypotension?
What are some symptoms of hypotension?
<90/<60
If stand up and systolic BP decreases >20mmHG or diastolic BP decreases >10mmHg, associated with dizziness and fainting. More frequent in elderly and can be caused by drugs e.g. antihypertensives and alcohol.
CNS: dizziness, impaired cognition, lethargy
Muscle: paracervical ache, fatigue
Heart: angina (due to hypoperfusion of heart, esp. during exercise)
How is hypertension diagnosed?
What is the method for taking BP?
How common is hypertension in the UK?
Perisistant systolic BP >140/>90, from repeated measurements on seperate occasions days/weeks apart. Pt properly prepared and postioned for at least 5 mins. Caffiene, exercise, smoking avoivded for at least 30min before BP taken. If poss 24h ambulatory BP monitoring.
Use appropriate size cuff, inflate 20-30mmHg above loss of radial pulse, deflate at 2mmHg/s, 1st sound = systolic BP, disappearance of sound = diastolic BP
Half UK male population has higher than optimal BP, more common as get older.
Why is there a general increase in systolic BP as you get older?
Elevated arterial BP is a major cause of premature vascular disease leading to what 4 diseases?
Which kills more people - vascular disease or cancers?
Elastin replaced with collagen so arteries less compliant, normal aging process.
1) Stroke
2) CHD
3) Renal impairment
4) Peripheral vascular disease
CDV mortality risk is proportional to the increase in BP
(NB: Framingham studies: hypertensives have 6x increase in stroke, 3x increase in cardiac death and 2x in peripheral arterial disease)
Roughly the same
Why is it important to control hypertension in diabetics?
How might chronic hypertension damage heart structure?
Most have damaged BVs - microvascular damage to endothelium of capillaries (e.g. in eye v. vulnerable). If poss lower it to below the max ok for non-diabetics.
Myocardial fibres undergo hypertrophy due to the greater afterload. The blood supply to the enlarged muscle may not keep up -> ischaemia -> angina.
What type of hypertrophy is this?
What changes to the heart rate does this kind of hypertrophy cause?
What happens in the other kind of hypertrophy?
Which is the worst kind of hypertrophy?
Concentric: wall thickened and lumen diameter reduced (but increases force of contraction and decreases stroke volume = more force, less C.O.)
Size of ventricular chamber decreases so to maintain C.O, HR must increase.
Eccetric: whole ventricle enlarges (wall may or may not increase in thickness) -> weaker heart so can lead to heart failure.
Eccentric
Chronic hypertension can damage the eyes, as their BV are sensitive to hypertensive damage. What are the signs of retinal damage?
Arteriolar narrowing
Abnormalities at points where arterioles and venules cross
Silver/copper wire arterioles (centre shines due to reflected light)
Retinopathy lesions e.g. microaneurysms, blot and flame hemorrhages, cotton wool spots and papilledema (swelling of optic disc - severe)
Thus EYE EXAM crucial in someone with repeated hypertension.
NB: other diseases can result in retinopathy e.g. diabetic retinopathy, and retinopathy due to autoimmune disease and anemia. Mild signs can be see in normal people.
What can you see in this eye examination?
Silver wiring appearance of arteries in hypertensive retina
What can you see in this eye examination?
Cotton wool spots in hypertensive retina - hemorrhages healed up
What is
a) primary hypertension?
b) secondary hypertension?
a) 90-95% cases, no obvious underlying cause, strong polygenic familial trend
b) 5% cases, clear underlying cause including renal/renovascular disease, endocrine disease (cushings’s or conn’s syndrome), coarctation of aorta = narrower so heart has to beat harder -> higher BP in arms and legs, iatrogenic (hormonal/pill, NSAIDs), thyroid (hyper/hypo)/ parathyroid disease
Describe the 2 factors that control BP?
What 2 elevated hormones are found in the blood of some patients with hypertension?
1) Neuronal: baroreceptors in carotid artery, rapid response, maintains blood flow to brain during postural changes or exercise. Controls fast changes in output of sympathetic NS
2) Hormonal: RAAs, maintains steady BP, by controlling angiotensin II level and resting tone of sympathetic NS. Chronic hypertension associated mainly with pathology in RAAS
Renin, angiotensin II
Why should dietary salt reduction and diuretics always be part of hypertension treatment?
Do all patients show the same reductions in BP on low salt diets?
What are normal serum sodium levels?
What is hyponatremia? List some symptoms.
High renin and angiotensin levels lead to excess Na+ and thus water retention
No - 50% so much greater reductions on low salt diets than ‘salt insensitive’ patients. Salt sensitivity is more common in patients with Afro-Caribbean origin - salt restriction helpful so don’t loose too much salt in urine when sweat.
135-145mmol/L
extrafluid sodium (inc. blood plasma) <135mmol/L, serious -> can cause brain swelling. Symptoms include fatigue, confusion, nausea, headache, seizures, coma.
What is the link between diabetes and hypertension?
What is the link between obestiy and hypertension?
What 3 things make up the metabolic syndrome?
Hypertension present in about 40% of pts with T2 diabetes, increases with age. Poss because diabetes damages kidneys and induces excess renin release. 70% of T2 diabetics die from CDV (stroke, CHD, MI) so need antihypertensives.
Strong correlation between BMI >30 and primary hypertension. Obesity increases renal renin release, angiotensin formation and Na+ retention. High levels of leptin (due to increased number of fat cells) increase sympathetic vasoconstriction in pts. Obesity also associated with hyperinsulinaemia - insulin-induced hypokalaemia increases plasma renin and angiotensin II
Obesity, hypertension, insulin resistance
