Hypertension Flashcards
when is blood pressure at the highest (large arteries)
when it is ejected from the heart
as the aortic valves close the pressure drops to diastolic pressure
this is know as the pulse pressure
what is the mean arterial pressure defined as
diastolic pressure plus a third of the pulse pressure
in tachycardia this rises to around a half
what controls blood pressure
the kidneys - main source and long-term
short term - renin angiotensin system, capillaries, baroreceptor reflex, aldosterone system
what is hypertension
blood pressure that is too high
bp level above which investigation and treatment do more good than harm
how does blood pressure change during the day
normally lower at night
can be affected by how it is measured
affected by standing/sitting
need many careful measurements throughout the day to get an accurate reading
how can BP be measured
sphygmomanometer
ambulatory blood pressure monitor
home monitoring
upper arm is best place to measure
measure for minimum 5 mins, may need to reset the cuff 3 or 4 times
readings 3 times over several weeks, in and out of hospital, and while standing and sitting
what is CVD
cardiovascular diseases
mainly refers to diseases affecting coronary heart disease, MI, angina, SCD, heart failure, cerebrovascular diseases, stroke, TIA, cerebrovascular accident, other arterial diseases (peripheral vascular disease)
hypertension is one of the biggest risk factors for CVD
risk factors for CVD
age, high bp, high cholesterol, increased BMI, impaired glucose tolerance, decreased renal function, smoking, physical inactivity, strong family history, certain races
NICE diagnosis of hypertension
conventional bp of >140/90
ambulatory bp/home of >135/85
requires both
in cases where initial bp is severe (>180/120), abpm is unwarranted
what is white coat hypertension
discrepancy of >20/10 higher clinic bp compared to average abpm/home bp
what is target organ damage
hypertensive damage to organs
heart - LV hypertrophy
kidneys - reduced filtration rate
eyes - retinopathy
this can extend to life-threatening conditions, such as new onset confusion, chest pain, signs of heart failure/acute kidney injury
what is accelerated hypertension
severe bp increase to >180/120, usually with new/progressive organ damage
often severe hypertensive retinopathy
who is treated for hypertension
people with the highest sustained bp - grade 2 hypertension + (>160/100 and 150/95 at home) or target organ damage
people with the highest absolute risk - already with CVD, diabetes, chronic kidney disease, 10yr CVD risk of >10%, target organ damage
treatment for people with a non-clinically significant bp
advice about lifestyle changes (weight loss, limit salt intake, regular exercise etc)
bp kept under review (1-2 times per year if mild)
may warrant drug treatment if they remain hypertensive
exceptions to standard no longer hypertensive bp
chronic kidney disease or diabetes - target bp <130/80
>80yrs or higher risk to lowering bp = target bp <150/90
if frail/multimorbidities make lowering bp higher risk - relax bp goals
initial investigation for hypertension
history and examination - past bp levels, cvd and cvd risk factors
blood pressure - clinical and home/ambulatory
blood test
urinalysis
ecg when available
if bp particularly high review urinalysis, glomerular filtration rate, ecg, fundoscopy (eye examination) and symptoms
drugs used to treat hypertension
<55yrs - ace (angiotensin converting enzyme) inhibitor, or angiotensin receptor blocker (not in pregnant/possibly pregnant people)
>55yrs or Afro-Caribbean descent - calcium channel blocker
if blood pressure remains high then you combine the drugs
if its still high treatment is a diuretic
if bp is resistant measure potassium, if high use a alpha/beta blocker, if not high use a mineralocorticoid blocker
causes of primary hypertension
impairment in the kidney regulation of body salt balance
genes
environment
foetal programming
in primary hypertension underlying cause is not understood
