Hypertension and Stroke
Cards (20)
- Hypertension is elevated blood pressure. When measured by sphygmomanometer, listen to Korotkow sounds:
- Systolic pressure (contracting) when sounds appear
- Diastolic when they disappear
Blood pressure shows variation throughout the day - Level of blood pressure that constitutes hypertension:
- Above 140/90 mmHg was the previous standard
- Now tend to treat according to level of blood pressure and overall cardiovascular risk
- Measuring blood pressure:
- Use device which is recommended by BHS (British Hypertension Society)
- Pt should be sitting: at least 2 measurements - then take the average of those 2 readings
- Ambulatory blood pressure monitoring
- Variability between home and clinic
- "White coat effect"
- Pathophysiology of hypertension:
- Bursting effect
- Cerebral haemorrhage
- Dissecting aneurysm
- Can have more insidious effects
- CHD (coronary heart disease)
- Stroke
- Renal failure
- Arteriosclerosis
- Aetiology of hypertension = essential hypertension in 90% of cases
- Poly-causal
- Essentially a diagnosis of exclusion
- Multiple gene loci influence
- Environmental factors: obesity, salt intake, and lack of exercise
- Secondary hypertension:
- Commonest causes = renal
- Renal artery stenosis (typically seen in older pts with vascular disease)
- Endocrine causes
- Conn's syndrome
- Cushing's syndrome
- Instrinsic renal disease eg glomerulonephritis
- Effects of elevated blood pressure:
- Heart = increases risk of coronary heart disease (CHD)
- LVH (left ventricular hypertrophy), and possible arrhythmias
- Aortic aneurysm
- Peripheral vascular disease - arteriosclerosis
- Cerebral circulation - increased risk of cerebral infarction and cerebral haemorrhage
- Hypertensive encephalopathy - severe hypotension, coma and seizures
- Eye changes
- Blood vessels attenuated
- Haemorrhages
- Can be sight-threatening
- Complications of hypertension:
- Myocardial infarction
- Stroke
- Cerebral infarction
- Brain haemorrhage
- Multi-infarct disease
- Malignant hypertension
- Hypertensive encephalopathy
- Dissecting aortic aneurysm
- Peripheral vascular disease
- Non-therapeutic treatment measures for hypertension:
- Weight reduction
- Exercise
- Decrease salt intake
- Alcohol reduction
- Treatment measures that reduce cardiovascular risk, but not blood pressure:
- Stop smoking
- Reduced saturated fat
- Increase intake of oily fish
- Tailored treatment for hypertension:
- Treatment should follow sensible lines
- Should take account of patient other problems, likely side effects e.g. heart failure, diabetes - ACE inhibitor
- A stroke is a neurological deficit of a presumed vascular cause.
- A TIA (transient ischaemic attack) is a neurological deficit of presumed vascular cause - like a stroke, but lasts <24 hours.
- PRIND (prolonged reversible ischaemic neurological deficit) = like a TIA (transient ischaemic attack), but lasts longer than 24 hours.
- Stokes usually have a rapid onset of symptoms - same symptoms over weeks/months suggest alternative diagnosis
- Symptoms of a stroke:
- Paralysis
- Loss of sensation
- Double vision
- Unsteadiness
- Loss of speech
- Loss of ability to use and understand language
- Stroke symptoms depend on what part of the brain is affected, and what part of the brain is affected depends on the arterial territory affected.
- Prevalence of risk factors for strokes:
- Hypertension - 52%
- Vascular disease elsewhere - 38%
- Smoking - 45%
- Diabetes - 10%
- TIA (transient ischaemic attack) - 14%
- Atrial fibrillation - 5%
- Treating raised blood pressure reduces the risk of stroke in those who are at risk of stroke and those who have had a stroke/TIA (transient ischaemic attack) before.
- Forms of stroke prevention:
- Surgery - for pts with narrowed carotid arteries
- Aspirin and other anti-platelet drugs
- Lower cholesterol
- Warfarin (dental treatment ok if INR <4)
- In pts with atrial fibrillation (irregular pulse)
- Or other cardiac source