Please enable JavaScript.
Coggle requires JavaScript to display documents.
Hypertension (Pathophysiology (Major risk factor for stroke, MI, heart…
Hypertension
Pathophysiology
Major risk factor for stroke, MI, heart failure, chronic renal disease (as blood passes through kidneys), cognitive decline
-
-
A 2mg rise in systolic BP is associated with a 7% increased mortality from IHD and a 10% increased mortality from stroke
-
-
Hypertension accelerates atherosclerosis, it thickens the media of the muscular arteries and causes endothelial cell dysfunction
Investigations
To exclude secondary causes, take U&E and urine analysis
-
-
-
-
Treatment
Threshold for Treatment
If ABPM is <135/85 mmHg, do not treat
If ABPM >135/85 mmHg, treat if CV risk >20%/10 years or end organ damage, otherwise give lifestyle advice
If clinic BP > 140/90 mmHg, take an ambulatory BP reading, calculate CV risk and organ damage
If clinic BP >180/110 mmHg, immediately start treatment and refer
Goals of Treatment
-
-
-
Antihypertensives target cardiac output, peripheral resistance, renin-angiotensin-aldosterone system and local vascular mediators
-
Drugs
Calcium Channel Blockers
Benxothiazepines: Diltiazem, dilates peripheral arteries
Side effects due to vasodilation: flushing, oedema, headache
Phenylalkylamines: Verapamil, negative chronotropic + inotropic effects
Side effects due to -ve chronotropic effects: bradycardia, AV block
Dihyropyridines: Amlodipine, dilates peripheral arteries
Beta Blockers
Inhibits noradrenaline release so can cause bradycardia, hypotension, cold peripheries, erectile dysfunction
Contraindicated in asthma, COPD, PVD
-
Not in first line treatment, consider for young people who are intolerant of ACE inhibitors and ARB
Examples: bisoprolol (beta 1), propranolol (beta 1+2)
-
Diuretics
-
-
Loop diuretics - affect loop of Henle, short acting e.g. furosemide. Can cause hypovolaemia, hypotension and hypokalaemia
Thiazides - affect distal tubule e.g. indapamide, bendroflumethiazide, can cause erectile dysfunction
-
ACE Inhibitors
Side effects due to increased kinin production: cough, rash, anaphylaxis
-
Side effects due to reduced angiotensin II: Hypotension, acute renal failure, hyperkalaemia, teratogenic effects in pregnancy
By reducing angiotensin II production, blood vessels dilate and there is less water retention from preventing aldosterone release
Examples: ramipril, enalapril
Treatment Steps
For both groups, if BP is not controlled, then combine ACE/ARB with CCB
If BP is still not controlled, combine ACE/ARB + CCB with a thiazide diuretic
If under 55 years, give ACE inhibitor or ARB initially
In cases of resistant hypertension, add a spironolactone, alpha blocker or beta blocker
If over 55 OR Afro-Caribbean of any age, then give CCB initially
Types of Hypertension
-
Malignant
-
-
-
Can precipitate AKI, heart failure and encephalopathy
-
If untreated, 90% die within 1 year and treated 70% die within 5 years
Secondary
Renal disease - the most common secondary cause e.g. glomerulonephritis, polycystic kidneys, systemic sclerosis
Endocrine disease e.g. Cushing's, Conn's, acromegaly, hyperparathyroidism
-
-
Pregnancy, oral contraceptive pill
Cocaine, amphetamines, steroids
White Coat
Elevated clinic pressure due to nerves, but a normal pressure at home. No need to treat but patient is has a higher risk of developing hypertension in the future
-
-