Hypertension Flashcards
(27 cards)
Definition of hypertension?
140/90mmHg
What is malignant hypertension?
a.k.a accelerated phase hypertension
A rapid rise in blood pressure leading to vascular damage, characterised by fibrinoid necrosis.
It can cause acute renal failre, acute heart failure and encephalopathy
What are the signs and symptoms of malignant hypertension?
Severe hypertension (200+/130+) Bilateral retinal haemorrhages Bilateral retinal exudates Papilloedema Headache Visual disturbance - e.g. scotoma or blurred vision Seizures Nausea and vomiting
Classification of hypertension
Stage 1 - clinic BP 140/90mmHg and - ambulatory BP daytime average 135/85mmHg Stage 2 - clinic BP 160/100mmHg and - Ambulatory daytime average 150/95mmHg Stage 3/severe hypertension - clinic BP 180+mmHg systolic OR - 110+mmHg diastolic
What are the two possible causes of hypertension?
Primary - essential hypertension, idiopathic
Secondary - due to a systemic disease
Name some of the causes of secondary hypertension
Renal disease
- renal artery stenosis, chronic glomerulonephritis, chronic pyelonephritis, PCKD and CKD
Endocrine
- DM, hyperthyroidism, Cushing’s syndrome, Conn’s syndrome, hyperparathyroidism, phaeochromocytoma, CAH and acromeagly
CVD
- Coarction of aorta and fluid overload
Drugs e.g. adrenaline, corticosteroids, MAOIs and OCP
Pregnancy (pre-eclampsia)
Clinical features of hypertension
Asymptomatic - regular screening
May show s/s of cause
- renal artery bruit (renal artery stenosis)
-radiofemoral delay (coarctation of the aorta)
What are the signs of chronic hypertension?
Hypertension retinopathy
How is hypertensive retinopathy graded?
Stage 1 - tortuous arteries with thick, shiny walls
Stage 2 - AV nipping (narrowing where arteries cross veins)
Stage 3 - flame haemorrhages and cotton wool spots
Stage 4 - papilloedema
How is hypertension diagnosed?
Regular blood pressure screening
- above 140/90 is suspected hypertension
- above 180/120 is severe hypertension (immediate treatment required)
24 hour ambulatory BP monitoring confirms the diagnosis
- below 135/90 is normal (above this is confirmed hypertension)
What other investigations (not BP monitoring) should be performed to rule out a secondary cause?
Bloods
- lipid profile
- fasting glucose
- U&Es (low potassium = Conn’s syndrome, high calcium = hyperparathyroidism)
Fundoscopy - hypertensive retinopathy
ECG - ischaemic change
Echo - LVH
Renal USS/angiogram - renal artery stenosis
Urine dipstick - kidney damage
12 hour urinary VMA - urinary catecholamines released by neuroendocrine tumours
Urine free cortical - Cushing’s
Who gets treated in hypertension
Stage 1 get medication if - 10 year CV risk of >20% - signs of end organ damage - established CVD - renal disease -DM Stage 2 always receive medication Stage 3 receives immediate medication
What are the goals of treating hypertension?
Target BP changes depending on age and co-morbidity
- age <80 means target is <140/90mmHg
- age > 80 means target is <150/90mmHg
- if diabetic the target is <130/80mmHg
What are the two methods of treating hypertension?
Lifestyle changes
Medical treatment
What lifestyle changes should a person with hypertension undertake?
Smoking cessation Low fat/low salt intake Reduce alcohol Exercise Wight loss if obese
What are the four steps of medical treatment in hypertension?
Step 1
- age <55yr = ACEI or ARB
- age >55yr or black = calcium channel blocker
Step 2
- ACEI/ARB + calcium channel blocker
Step 3
- ACEI/ARB + calcium channel blocker + thiazide diuretic
Step 4 (resistant hypertension)
- ACEI/ARB + calcium channel blocker + thiazide diuretic + alpha/beta-blocker
- seek expert advice
What non anti-hypertensives can be considered for treatment in hypertension?
Aspirin >55yrs
Statin - reduces cardiovascular risk
Mechanism of action of an ACE inhibitor
Inhibits the conversion of angiotensin 1 to angiotenin 2 (a vasoconstrictor)
Less angiotensin 2
- less vasocontriction
- less aldosterone released from adrenal cortex
Less aldosterone
- less sodium/fluid retention
- decreased blood volume
What are the indications for ACEI?
Hypertension
Heart failure
Chronic Kidney Disease
Side effects of ACEI
Dry cough Hypotension Hyperkalaemia Renal impairment (avoid use in AKI) Angioedema
Mechanism of action of non-rate limiting calcium channel blockers (e.g. amlodipine)
Blocks L-type calcium channels - prevents calcium entry into the myocytes
- myocardial and smooth muscle contractility decreased
Dilation of coronary blood vessels reduces afterload
What are the side effects of non-rate limiting calcium channel blockers
Ankle oedema Abdominal pain/nausea Palpitations Flushing Headaches Dizziness
Mechanism of action of rate limiting calcium channel blockers (e.g. verapamil)
Blocks L-type calcium channels, preventing the entry of calcium into myocytes
- smooth muscle and myocardial contractility is decreased
Dilation of coronary blood vessels reduces afterload
Decreases heart rate by prolonging AV node conduction
What are the side effects of rate limiting calcium channel blockers
Constipation Headache/dizziness Hypotension GI disturbance Bradycardia Peripheral oedema
