Hypertension Flashcards
What is hypertension?
- Defined as sustained BP >140/90 mmHg
- Raised BP in the systemic vascular bed
How do you diagnose hypertension?
- Blood pressure has a skewed distribution within the population
- Don’t rely on single reading
- Assess over period of time
- Sustained BP >140/90mmHg on 2 separate readings
- Confirm with 24hr ambulatory BP monitoring
What is the target for BP control?
- < 140/90
- < 130/80 in diabetes
- 150/90 if aged >80
- Reduce BP slowly, rapid reduction can be fatal
- A target of 120/80 proven to be beneficial
Would you treat a patient with >140/90 mmHg BP?
The decision depends on the risk of coronary events, presence of diabetes, or end-organ damage.
Treat those with >160/100mHg (or ABPM >150/95).
BP on average is lower in young people and a study shows there is substantial benefit in treating 80+ age group.
What is the most common form of hypertension?
Essential/primary HTN - 95% cases
What is the aetiology of essential/primary hypertension?
No underlying cause but associated with:
- Genetic component - FHx
- Black ancestry
- Low birthweight
- Obesity
- Excess alcohol intake
- High salt intake
- Metabolic syndrome: obesity, DM2, hypercholesterolaemia
Secondary hypertension is ~ 5% of cases, what can it be caused by?
- Renal disease (most common): glomerulonephritis, diabetic nephropathy, polycystic kidneys, renovascular disease
- Endocrine: Cushing’s syndrome, acromegaly, thyroid disease, hyperparathyroid disease, Conn’s syndrome, Adrenal hyperplasia, phaeochromocytoma
- Others: Aortic coarctation, pregnancy, liquorice
- Drugs: NSAIDs, oral contraceptives, steroids, sympathomimetics, vasopressin, MAO inhibitors, carbenoxalone
What is the flowchart/diagram for managing suspected hypertension / when should you act?
What are the signs and symptoms of hypertension?
- Usually asymptomatic
- Always examine CVS fully and check for retinopathy (haemorrhages, exudates, papilloedema)
- Renal disease: renal bruits, palpable kidneys, proteinuria, haematuria
- Endocrine disease: attacks of sweating, tachycardia in phaeochromocytoma, symptoms of Cushing’s, acromegaly etc
- Coarctation of aorta: radiofemoral delay, weak femoral pulses, mid-late systolic murmur
What is malignant hypertension and its effects on the kidney, brain, retina and CVS?
Described as rapid rise in BP with diastolic BP >120mmHg in conjunction with bilateral retinal haemorrhages and exudates. If untreated, it will result in end-organ damage to the:
- Kidneys: haematuria, proteinuria, progressive renal failure
- Brain: cerebral oedema, haemorrhage, seizures
- CVS: acute heart failure, aortic dissection
- Retina: flame shaped haemorrhages, cotton wool spots, exudates, papilloedema
What are the possible complications of hypertension?
- Coronary artery disease
- Cerebrovascular accident
- Left ventricular hypertrophy
- Congestive heart failure
- Retinopathy
- Peripheral artery disease
- Chronic kidney disease
- Aortic dissection
- Malignant hypertension
What investigations can be done to look for causes of hypertension and possible complications?
- Serum U&E: evidence of renal impairment (-> if so, do US, angiography), eg. hypokalaemia occurs in Conn’s
- Urine stix test: for protein + blood
- Fasting blood for lipids (total + HDL cholesterol) + glucose
- ECG: look for end-organ damage (LVH, MI)
- Fundoscopy: look for retinal changes
What are the stages of hypertension?
- Optimal = < 120/80
- Normal = < 130/85
What characteristics might an ECG show for hypertension?
- left ventricular hypertrophy
- tall R waves in left lateral leads (I and V6)
- deep S waves in right-sided pericordial leads (V1 and V2)
- maybe left axis deviation
- if there is significant left ventricular ‘strain’ then there are also inverted T waves in V5 and V6 and possible ST depression
- QRS may be slightly prolonged
What is the conservative, life-style management for hypertension?
- diet: high consumption of veg/fruits and low-fat diet, low salt diet, reduced caffeine intake
- regular exercise: 30min of mod-intensity aerobic exercise 5-7days/week
- reduction of alcohol intake per week
- stop smoking
- overall lose weight
What impact does reduced salt diet have?
- low salt diet is recommended
- aiming for less than 6g/day, ideally 3g/day
- average adult in UK consumes 8-12g/day of salt
- recent BMJ paper showed lowering salt intake can have significant effect on BP
- eg. reducing salt intake by 6g/day can lower systolic BP by 10mmHg