Hypertension. Flashcards
how is blood pressure calculated?
Cardiac output x peripheral resistance.
What is hypertension?
A disorder in which the level of sustained arterial pressure is higher than expected for the age, sex, and race of the individual. WHO defines this as being greater than 140/90. It must be measured over a sustained period of time due to normal fluctuation.
What can alter cardiac output?
HR, contractility of the heart and the blood volume.
What can alter peripheral resistance?
Constrictors e.g. Angiotensin II and catecholamines and dilators e.g. Nitric oxide and prostaglandins.
What is the global incidence of hypertension?
Varies between countries, higher in black populations, lower in the South Pacific. Age (main driving factor) and genetics are key.
What is the ideal blood pressure?
120/75
What is normal blood pressure?
120-129/75-84
What is high normal blood pressure?
130-139/85-89.
What is stage 1 (mild) hypertension?
140-159/90-99.
What is stage 2 (moderate) hypertension?
160-179/100-109.
What is severe hypertension?
Grater than or equal to 180/110.
Who do we treat for hypertension?
All with stage 2 hypertension. For those with stage 1 the choice depends on the risk of coronary events, the presence of DM or end organ damage.
How do we classify hypertension?
Either according to cause (primary or secondary) or consequences (benign or malignant).
What is primary hypertension?
Also called essential hypertension. Makes up 90-95% of cases. It has no obvious cause but has genetic factors and is linked to salt intake, protein intake (RAAS) and sympathetic activity.
What amount of primary hypertension cases are said to be salt sensitive?
Around 25%
What is salt sensitive hypertension?
Increased dietary salts lead to increased bp. It can be controlled by a low salt diet.
What is a common type of secondary hypertension in renal disease?
Salt sensitive.
What is secondary hypertension?
Hypertension where an underlying cause is implicated. Comprises about 5% of cases.
What is the most common cause of secondary hypertension?
Renal disease.
What are the two different types of renal diseases that cause secondary hypertension?
75% Intrinsic and 25 % renovascular disease.
What are some examples of intrinsic renal diseases?
Glomerulonephritis, polyarteritis nodosa (PAN). Systemic sclerosis, chronic polynephritis or polycystic kidneys.
What different types of renovascular disease and who gets them?
Fibromuscular dysplasia - rare but usually young females.
More commonly atheromatous - elderly male smokers with PVD for example.
What types of disease and factors are liable to cause secondary hypertension?
Renal, endocrine and others e.g. Coarctation, pregnancy and drugs e.g. MAOIs and the pill.
Give examples of endocrine diseases that cause secondary hypertension?
Cushings, Conn’s syndrome, phaeochromocytoma, acromegaly and hyperparathyroidism.
What does cushings result in?
Results in an over secretion of corticosteroids.
What does Conn’s syndrome result in?
Excess aldosterone.
What does Phaeochromocytoma result in?
Excess noradrenaline.
What is isolated systolic hypertension?
Most common form in the UK, affecting over 50% of over 60’s. Results from arteriosclerosis of the large arteries. Doubles the risk of MI and trebles the risk of CVA.
What is benign hypertension?
Asymptomatic and often found incidentally. Causes increased morbidity.
What are the eventual outcomes of hypertension?
LVH, congestive cardiac disease. Increased atheroma, increased aneurysm rupture and aortic dissection. Berry aneurysms and renal disease.
What is malignant hypertension?
Severe hypertension e.g. Systolic over 200 and diastolic over 130-140 plus bilateral retinal haemorrhages and exudate. May or may not show papillodema.
What can malignant hypertension develop from?
Benign primary or secondary hypertension or de novo.
What are the symptoms of malignant hypertension?
Headaches plus or minus visual disturbance.
What are the survival rates for malignant hypertension?
Untreated 90% die in a year. Treated 70% survive for 5 years.
What are the outcomes of malignant hypertension?
Acute renal failure, heart failure, encephalopathy, cerebral oedema (seen as papillodema).
What is papillodema?
Swelling of the optic disc.
What are the mythological hallmarks of malignant hypertension?
Fibrinoid necrosis and endarteritis of blood vessel walls.
What is pregnancy associated hypertension?
Affects up to 10% of pregnancys and causes increased maternal and foetal morbidity and mortality. Comes in the form of pre-eclampsia or eclampsia. It resolves following birth.
What are features of pre-eclampsia?
Hypertension and proteinuria.
What examinations should we do for hypertension?
Full CVS exam. Check for retinopathy. Look for signs of underlying disease e.g. Renal - renal Bruits or palpable kidneys. Radial femoral delay. Weak femoral pulse from coarction. Cushings syndrome. Look for end organ failure e.g. LVH and retinopathy.
What tests should we do for hypertension?
Quantify overall risk: fasting glucose and cholesterol.
Tests for end organ damage: ECG and urine analysis to look for proteinuria.
Exclude secondary causes: blood tests for raised creatinine. U+E (e.g. Low potassium in Conns and raised calcium in hyperparathyroidism).
If clinical BP is over 140/90 offer ABPM.
How do we grade hypertensive retinopathy?
I - torturous arteries with thick shiny walls. Slight or modest narrowing of the retinal arterioles with an arterial venous ratio of greater than or equal to 1:2.
II - av nipping or modest to severe narrowing with a:v or under 1:2.
III - flame haemorrhages and cotton wool spots.
IV - papilloedema.
What is ABPM?
Ambulatory blood pressure monitoring. 2 measurements per hour for waking hours, usually over 14 days. Readings are usually lower then clinical readings so we must add 12/7.
What is HBPM?
Home blood pressure monitoring. Two seated measurements 1 min apart twice a day for four to seven days. The measurements for the first day are discarded and the rest averaged.
What is the treatment for hypertension?
Stage 1- offer lifestyle interventions, if under 40 years old, offer this and specialist intervention.
Stage 1 plus target organ damage or ten year risk of CVD over 20%. Offer the above and anti-hypertensive drug therapy.
Stage 2 - straight to drug treatment.
What is the goal of hypertension treatment?
To get a bp of under 140/85 or 130/80 for diabetic patients.
For patients over the age of 80 we aim for under 150/90.
What lifestyle interventions do we advise?
Reduced sodium and caffeine diet. Weight reduction (1mmHg for each kg lost). Exercise 15 mins minimum per day. Alcohol reduction and smoking cessation.
What should NOT be the first choice in treatment for primary hypertension and why?
Beta blockers, as they can turn uncomplicated hypertension into complicated, with increased arrhythmias, CAD and CHF.
Is monotherapy best for hypertension? Why?
No. Starting with two drugs is always better than 1 so we shouldn’t just start with the maximum tolerated dose of 1. Adding a second drug is 5x more effective than titration 1. It also gives fewer side effects.
What drugs are commonly used to treat hypertension?
Ade inhibitors, angiotensin II receptor blockers (ARB)’ calcium channel blockers and thiazides. Sometimes use, alpha blockers, beta blockers and other diuretics if these don’t work.
What is step 1 in hypertension treatment?
55 years, or a person of any age of African or Caribbean descent. Calcium channel blocker or thiazides.
What is step 2 in hypertension treatment?
Ace inhibitor or ARB and either CCB or thiazides for all patients.
What is step 3 in hypertension treatment?
Ace inhibitor or ARB and CCB and thiazides.
What is step 4 in hypertension treatment?
It’s for resistant hypertension. So we give an ace inhibitor or ARB, a CCB, a thiazides and conSider adding Either: a further diuretic or an alpha or beta blocker, and consider seeking specialist advice.
What is a side effect of ace inhibitors and what can we give instead in this case?
A cough and we can give an ARB.
When should we consider beta blockers other than in resistant hypertension?
In young people - particularly if they are intolerant or have a contraindication to ace or ARB’s. If they are a woman of child bearing age or there is increased sympathetic drive.
Should be give beta blockers and thiazides together? Why?
No as they increase the risk of new onset diabetes. If already on beta blockers, consider calcium channel blockers instead.
What can be some causes of resistant hypertension?
Non-concordance, white coat effect, pseudo hypertension, lifestyle factors, drug interactions, secondary hypertension or true resistance.
What treatment should we give for hypertension to those suffering from angina?
Beta blockers or calcium channel blockers.
What treatment should we give for hypertension to those suffering from CCF?
Ace inhibitors and beta blockers.
What treatment should we give for hypertension to those suffering from diabetic neurophathy?
Ace inhibitors or ARBs.
What treatment should we give for hypertension to those suffering from prostatism?
Alpha blockers with caution.
What treatment should we give for hypertension to the elderly?
Thiazides.
How should we treat malignant hypertension?
Bed rest and beta blockers or CCB po.
What should we never try to do when managing hypertension?
Lower BP immediately. Instead gradually over days not hours. Sudden Bp drops can cause strokes.
What drug should we never use for malignant hypertension and why?
Sublingual nifedipine. It will cause a sudden drop in Bp and therefore is a stroke risk.
