Hypertension Flashcards
what is stage 1 hypertension?
clinic blood pressure of 140//90 mmHg or higher and home blood pressure monitoring blood pressure of 135/85 mmHg or higher.
what is stage 2 hypertension?
clinic blood pressure of 160/100 mmHg or higher and home blood pressure of 150/95 or higher.
what is severe hypertension?
clinic systolic blood of 180mmHg or higher or clinic diastolic blood pressure of 110 mmHg or higher.
what causes hypertension?
walls of larger arteries lose their elasticity and become rigid, and the smaller vessels constrict.
what effect does hypertension have on the brain?
- most important risk factor for stroke.
- very high blood pressure can cause a leak in a weakened blood vessel, which then bleeds in the brain (cerebral haemorrhage)
- if a blood clots blocks one of the arteries narrowed by atheroma, it can result in cerebral infarction which causes a stroke.
what effect does hypertension have on the eyes?
high blood pressure can cause one of the vessels to leak or bleed (hypertensive retinopathy) vision may become blurred due to this.
what effect does hypertension have on the heart?
- risk of myocardial infarction - if the blood flow to the heart is blocked.
- congestive heart failure (CHF) - at first the heart can compensate for the increased work of pushing against the elevated pressure in the vessels by becoming thick (hypertrophic) at a later stage the heart may no longer be able to pump enough for the heart needs.
what effect does hypertension have on the kidneys?
kidney damage - persistent high blood pressure over time can Cause narrowing and thickening of the renal arteries. this causes the kidneys to filter less fluid and results in waste in the blood.
what effect does hypertension have on the arterial tree?
- atherosclerosis - speeds up the hardening and narrowing of arteries in the body.
- aortic aneurysm - the wall of the aorta may weaken due to dilatation of the aorta with risk of rupture.
what effect does hypertension have on peripheral vascular resistance (PVR)?
PVR increases. this in turn results in further increase in blood pressure.
what is another cause of increased PVR?
atherosclerosis
what are the two types of hypertension?
essential and secondary.
what is essential hypertension?
raised blood pressure without obvious cause.
what % of cases does essential hypertension account for?
90-95%
what is essential hypertension also known as?
primary or idiopathic hypertension
what is secondary hypertension?
raised blood pressure when there is an identifiable cause
when does secondary hypertension often develop?
before the age of 35
or
after the age of 55.
what is a rare but severe type of hypertension?
accelerated hypertension
what group of people is accelerated hypertension most common in?
african-americans
what is the pathological hallmark of accelerated hypertension?
accelerated microvascular damage. the small arteries and arterioles show fibrinoid necrosis and thrombus, including those of the optic fundi and the kidneys.
what does accelerated hypertension cause?
oedema and swelling of the brain.
what would happen in the absence of effective lowering of blood pressure in accelerated hypertension?
most likely death.
what are the risk factors of hypertension?
- race - african-americans more likely.
- gender - men more likely.
- age - higher risk when old
- environment
- obesity
- diabetes
- too much salt in diet
- stress
- abnormalities in the nervous and circulatory system and kidneys
- inactive lifestyle
what does the term ‘metabolic syndrome’ describe?
a group of cardiovascular risk factors - abdominal obesity, dyslipidaemia and insulin resistance.
how does ‘metabolic syndrome’ risk increase?
4x increase in risk of fatal coronary disease and 2x greater of cardiovascular disease.
what is the key feature of accelerated hypertension?
accelerated (grade IV) retinopathy
what are examples of causes of secondary hypertension (not renal or endocrine)?
- conn’s syndrome
- coarctation of the aorta - usually associated with a biscuspid aortic valve.
- Glucocorticoids
- NSAIDs
- pregnancy
- combined oral contraceptive pill
What are examples of renal disease causes of secondary hypertension??
- Glomerulonephritis
- chronic pyelonephritis
- adult polycystic kidney disease
- renal artery stenosis
What are examples of Endocrine disorders causes of secondary hypertension?
- Primary hyperaldosteronism
- Phaeochromocytoma
- Cushing’s Syndrome
- Liddle’s syndrome
- Congenital adrenal hyperplasia (11-beta hydroxylase deficiency)
- Acromegaly
What symptoms may cause hypertension cause if it is very high (>200/120 mmHg)?
- headache
- visual disturbance
- seizures
What test might be done on a patient with hypertension to check for end-organ damage?
- Fundoscopy: to check for hypertensive retinopathy
- urine dipstick: to check for renal disease
- ECG: to check for ventricular hypertrophy or ischaemic heart disease
What test do patients usually have following diagnosis?
- urea and electrolytes: to check for renal disease
- HbA1c: chest for co-existing diabetes mellitus
- Lipids: check for hyperlipidaemia
- ECG
- urine dipstick
What is the first-line treatment for hypertension in younger patients(<55 years old)?
Angiotensin-converting enzyme (ACE) inhibitor
What are common side effects of ACE inhibitors?
- Cough
- Angioedema
- Hyperkaleamia
What group of patients are ACE inhibitors less effective in?
Afro-Caribbean
What types of patients must ACE inhibitors be avoided in?
pregnant woman
What must be checked (and when) in patients with renovascular disease after starting ACE inhibitors?
renal function - 2-3 after starting.
What is the first-line treatment for hypertension in Older patients(>/= 55 years old)?
Calcium channel blocker
How do ACE inhibitors work?
inhibit conversion of angiotensin I to angiotensin II
How do calcium channel blockers work?
block voltage-gated calcium channels relaxing vascular smooth muscle and force of myocardial contraction
What are side effects of calcium channel blockers?
- Flushing
- ankle swelling
- headache
How do thiazide type diuretics work?
inhibit sodium absorption at the beginning of the distal convoluted tubule.
What are side effects of Thiazide type diuretics?
- Hyponatremia
- hypokalaemia
- dehydration
How do angiotensin II receptor blockers (A2RB) work?
Block effects of angiotensin II at the AT1 receptor
When are angiotensin II receptor blockers generally used?
when patients have not tolerated ACE inhibitors, usually due to the development of a cough
what is the side effect of angiotensin II receptor blockers?
hyperkalaemia
