Hypertension Flashcards
What is hypertension?
140/90mmHg.
Benefits from treatment with hypertensive agents in reducing cardiovascular, cerebrovascular and peripheral vascular risk.
What is the prevalence of hypertension?
30-40% of the adult population.
>50% of >60yr olds.
A risk factor for MI and stroke.
What are the complications of hypertension?
Heart - LVH, CHD, CHF, MI.
Peripheral vascular disease.
Eyes - retinopathy.
Affects the brain and kidneys.
What are the different stages of hypertension?
Stage I - >140/90.
Stage II - >160/100.
Stage III - >180/120.
What are the types of hypertension?
Primary - 90% of cases (idiopathic).
Secondary - 10% of cases. Caused by chronic renal disease, renal artery stenosis, or endocrine diseases (Cushing’s, Conn’s)
Incidence is highest in the young.
What are the risk factors of hypertension?
Smoking.
Diabetes (10x risk of MI).
Renal disease.
Male (2x risk).
Hyperlipidaemia.
Previous MI or stroke.
LVH (2x risk).
Lifestyle (exercise, diet).
How is age related to hypertension?
BP rises with age.
Aggressive BP treatment in the elderly can reduce the risk of stroke and MI.
How are genetics related to hypertension?
Familial hypertension (between siblings).
>30 recognised important genes, but individually account for <0.5mmHg each.
How is the environment related to hypertension?
Mental and physical stress increase BP.
White coat hypertensive patients have an increased risk of CVD.
How is diet related to hypertension?
A strong relationship between hypertension, stroke, and salt intake.
Reducing salt intake in hypertensive individuals does lower BP (difficult to restrict).
How is alcohol related to hypertension?
Small amounts tend to decrease BP.
Large amounts tend to increase BP.
Reduced consumption causes a decrease in BP over several days to weeks (small).
A common cause in young men.
How is weight related to hypertension?
Obese patients have a higher BP.
Weight loss causes a fall in BP.
Lower birth weight increases risk of hypertension development in later life.
How is race related to hypertension?
Black populations genetically retain salt more, and are more sensitive to changes in sodium.
What are the likely causes of hypertension?
Increased reactivity of resistance vessels - a hereditary defect of arteriolar smooth muscle.
Kidneys are unable to excrete enough Na+ for any given BP, so Na+ is retained, and BP increases.
What is the basis of treatment for hypertension?
Targeting SNS and RAAS.
Confirm diagnosis, assess risk factors, then assess end organ damage.
What are the investigations for end organ damage?
LVH - ECG / ECHO.
Proteinuria - urinalysis.
US - renal function.
What conditions are screened for in hypertension?
Renal artery stenosis.
Conn’s / Cushing’s.
Coarctation.
Drug induced.
Sleep apnoea.
What is Q-Risk?
Once risk has been assessed, set a target BP (<135/85). Start treatment when CVD risk is <10% in 10yrs.
How does treatment change with the staging of hypertension?
Stage I - antihypertensives for <80yr old patients with >135/85 and organ damage, established CVD, renal disease or diabetes.
Stage II - antihypertensives (>150/95).
How does the treatment of hypertension change with age?
For <40yr olds with any staging of hypertension, seek specialist evaluation of secondary causes of hypertension, and a more detailed assessment of potential organ damage.
For >80yr olds, also consider any co-morbidities.
What is the first step in choosing antihypertensives?
For >55yrs old, and black people of African or Caribbean family origin of any age) - CCB or a thiazide diruetic.
For <55yrs old - ACEI/ARB.
Not Afro-Caribbean - less effective, risk of angioedema.
Not child-bearing women - teratogenic in early stages, toxic to foetuses in later stages.
What are the consequent steps in choosing hypertensives?
Step 2 - add thiazide diuretic.
Step 3 - CCB, ACEI, and diuretic.
Step 4 (resistant hypertension) - consider compliance issues and higher dose thiazide diuretic treatment if blood K+ > 4.5mmol/L.
Consider further diuretic therapy with low-dose spironolactone.
What are antihypertensive drugs?
ACEIs (Ramipril, Perindropril).
Competitively inhibits ACEs.
Contraindications - hyperkalaemia, renal artery stenosis, fertile female.
With NSAIDs - renal failure.
What are ARBs?
Losartan, valsartan, candesartan.
Fewer side effects compared to ACEIs.
No cough.
What are CCBs?
Amlodipine and felodipine - vasodilators.
Nifedipine - women of childbearing age.
Used in >55yr olds.
Verapimil - rate limiting.
Reduces HR, and some vasodilation.
Bradycardia and constipation.
What are the contraindications and ADRs of CCBs?
Contraindications - acute MI, heart failure.
ADRs - flushing, headache, ankle oedema.
What is indapamide?
A thiazide diuretic.
First line treatment in mild/moderate hypertension in Afro-Caribbeans.
Can be used with other hypertensives.
Stroke and MI reduction.
What are the negative effects of thiazide diuretics?
Enhances the urinary excretion of sodium and reduces peripheral vascular resistance.
ADRs - gout, ED (not common).
What are uncommon agents used for the treatment of hypertension?
Doxazosin - opposes arterial smooth muscle concentration (ADRs - dry mouth, dizziness).
Methyldopa - used in pregnancy (ADRs - nasal congestion, orthostatic hypotension).
Hydralazine and minoxidil - vasodilators.
What are common treatment regimes for hypertension?
Age >55 or Afro-Caribbean:
CCB - thiazide - ACEI/ARB - beta blocker - uncommon agents.
Age <55:
ACEI - thiazide - CCB - beta blocker - uncommon agents.
