Hypertension Flashcards
Complications of hypertension
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What is hypertension?
The blood pressure above which the benefits of treatment outweighs the risks in term of morbitiy and mortality
NICE 2011 definitions of hypertension ( Stage 1, 2 + severe hypertension)
Stage 1 hypertension
- Clinic BP 140/90mmHg/higher
- ABPM daytime average 135/85mmHg or higher
Stage 2 Hypertension
- Clinic BP 160/100mmHg/higher
- ABPM daytime average 150/95mmHg/higher
Severe hypertension
-Clinic systolic BP 180mmHg/higher OR diastolic BP 110mmHg/higher
Causes of secondary hypertension
- chronic renal disease
- renal artery stenosis
- endocrine disease, cushing’s, conn’s syndrome, Phaeochromocytoma, GRA
Causes of primary hypertension
-unknown
Factors that increases risk of hypertension
- smoking cigarrrete (adds 20/10mmHg)
- diabetes mellitus
- renal disease
- Male (2x risk)
- hyperlipidaemia
- previous MI / stroke
- left ventricular hypertrophy(2x risk)
Sympathetic system activation
Causes:
- vasocostriction
- reflex tachycardia
- increased CO
These actions account for second to second blood pressure control
Function of Renin-angiotensin-aldesterone system
- maintanience of sodium balance
- control of BV
- control of BP
What activates RAAS?
- fall in BP
- fall in circulating volume
- sodium depletion
- Renin released by juxtaglomerular apparatus + convets Agiotensinogen>angiotensin I
- Angiotensin l >angiotensin ll ( via angiotensin converting enzyme
What is angiotensin II? State its function
A potent:
- vasoconstrictor
- anti-natriretic(sodium) peptide
- hypetrophic agent which stimulates myocyte + SM hypertrophy in arterioles
- stimulator of aldesterone release from adrenal glands
What is aldesterone? State tis
A potent:
-antinatriutetic + antidiuretic peptide
Aetiology of hypertension
Polygenic
-major/poly genes
Polyfactorial
- environment
- individual and shared
Likely causes of hypertension
-increased reactivity of resistance vessels + increase in peripheral resistance as a result of hereditary defect of the smooth muscle lining arterioles
A sodium homeostatic
- kidneys are unable to excrete appopriate amounts of sodium for any given BP. As a result, sodium + fluid are retained and BP increases
Other factors of Hypertension
- age
- genetics + FH
- environment
- weight
- alcohol intake
- race
The effect of age on BP
- BP increases with age due to decreased arterial compliance
- Hyper
The effect of genetics on BP
- history of BP
- correlation between siblings rather than parent-child
- > 30 genes account for 0.5mmHg each
The effect of the environment on BP (stress)
- mental/physical stress
- removing stress may not return BP back to normal
- True stress responders who have high BP when they attend doctor but normal BP will be resistant to treatment
The effect of sodium intake and diet
- correlation between sodium intake and BP
- reduction in sodium in hypertensive individuals will lower BP but in normotensives will have little effect
- reducing intake to <6gm/day
The effect of alcohol on BP
- small amounts decreases BO
- large amouns increases BP
- reversible
The effect of weight on BP
- obesity=higher BP
- reversible
The effect of birth weight on BP
-lower the birth weight, the higher the chance of hypertension and HD in future
The effect of race on BP
- caucasions have lower BP than black populations living in same environment
- Black populations living in rural africa have a lower BP than those living in towns
Secondary hypertension features
- removal of cause may/may not be reversible
- sustained Hypertension causes end organ damage to BV’s, heart and kidney
Causes of secondary hypertension
Renal disease
- chronic pyelonephritis
- fibromuscular dysplasia
- renal artery stenosis
- polycystic kidneys
Drug induced
- NSAIDs
- oral contraceptive
- corticosteroids
Pregnancy
-preeclampsia
Endocrine
- Conn’s syndrome
- Cushing’s disease
- phaepchromocytoma
- hypo/hyperthydroidism
- acromegaly
Vascular
-coarction of aorta
Sleep apnoea
Assesing the risk of BP
Assess end organ damage ECG LVH Echocardiogram LVH Proteinuria Renal ultrasound Renal function Screen for treatable causes Renal artery stenosis/FMD Cushings disease Conn’s Syndrome Sleep apnoea
Previous MI, stroke, IHD Smoking Diabetes mellitus Hypercholesterolaemia Family history Physical Examination
Treatment of hypertension
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Stage 1 hypertension treatment
- Antihypersensitive drug treatment <80yrs with ABPM >135/85 with 1/more:
- target organ damage
- CVD
- renal disease
- diabetes
- 10 year CV risk 20% or greater
If <40 yrs seek specialist evalation of secondary causes of hypertension + target organ damage assestment
If ovwe 80 yrs pressure target is <145/85
Stage 2 hypertension treatment
ABPM>150/95
-antihypersensitive drug treatment of any age
Step 1 to choosing antihypersensitive drug treatment
STEP 1
- offer antihypertensive treatment with CCB to people >55yrs and to black people of any age
- alternative to CCB ( oedema, intolerance, HF) offer thiazide-like diuretic
- If <55yrs offer ACEI/ARB ( not to blacks, women of child bearing age)
If diuretic treatment is to be initiated/changed, offer thiazide-like diuretic such as chlortalidone or indapamide
Step 2 to choosing antihypersensitive drug treatment
-add thiazide-type diuretic such as clortalidone/indapamide to CCB/ACEI/ARB
Step 3 to choosing antihypertensive drug treatment
-add CCB, ACEI, diuretic together
Step 4 to choosing antihypertensive treatment
if potassium blood <4.5 offer low dose spironolactone. ( caution in people with estimated GFR beacuse risk of hyperkalaemia)
-If high Blood potassium, offer higher dose thiazidide-like diuretic
State angiotensin converting enzyme inhibitors
Ramipril
- prevents ACE from converting angiotensin I>Angiotensin II
- prevents mechanism of angiotensin II ( vasoconstrictor and hypertrophogenic agent)
