Hypertension Flashcards
Explain hypertension to a patient
High blood pressure is an asymptomatic condition that can potentially cause damage to the blood vessels.
Having a high blood pressure puts you at a higher risk of having a stroke, IHD, heart failure, CKD, cognitive decline, premature death and a MI.
It is however manageable with medication to bring it down. Lifestyle factors also contribute to high blood pressure and these too should be addressed
Consequences of hypertension
Stroke (2mmHg increase = 10% increased risk)
Ischaemic heart disease (2mmHg increase = 7% increased risk)
Heart failure
CKD
Cognitive decline
Premature death
MI
Risk factors for hypertension
Obesity/Excess weight Smoking Poor diet High cholesterol Excess alcohol intake Family history Inactivity Caribbean/African descent
Grading hypertension
Grade 1 (mild) = 140-159 / 90-99
Grade 2 (moderate) = 160-179 / 100-109
Grade 3 (severe) = > 180 / >110
Isolated systolic hypertension = >140 / >90
How is hypertension diagnosed?
If Clinic BP = >140 / >90
- take a 2nd reading and use lowest - Offer ambulatory BP monitoring (ABPM)
If Clinic BP = > 180 / >110
- Start Anti-hypertensives - Investigate for target organ damage - Assess cardiovascular risk
Refer to specialist if:
- BP = >180/110 + Papilloedema +retinal bleed
- BP = >180/110 + Phaechromocytoma
- Suspecting secondary HTN
What are the two types of hypertensive crises?
Hypertensive Urgency:
- BP is acutely elevated >180/110
- No acute damage to target organs
- Severe headache
- Dyspnoea,
- Nose bleed
- Severe anxiety
- Management = oral medications
Hypertensive emergency:
- BP is acutely elevated > 180/110
- Severe/permanent damage to target organs
- Chest pain
- Dyspnoea
- Back pain, numbness, weakness
- Vision changes
- Difficulty speaking
- Encephalopathy (oedema, ICP and dysfunction)
- Papilloedema
- Nephropathy
- Management = IV medications, ICU admission
Explain the pathophysiology of hypertension
CO = HR x SV BP = CO x PR
Explain the Renin-angiotensin- aldosterone system
Renin causes the release of aldosterone
- Aldosterone increases the re-absorption of Na + H20
Renin converts Angiotensinogen –> Angiotensin I
ACE converts Angiotensin I —> Angiotensin II
- Angiotensin II is a potent vasoconstrictor
- Angiotensin II stimualtes aldosterone producton
Overall, the system increase CO and PR to increase BP
How is blood pressure controlled short-term in the body?
Autonomic nervous system
Baroreceptors
Chemoreceptors
Atrial volume reflex
How is blood pressured controlled long-term in the body?
Juxtaglomerular apparatus
What end-organ damage is seen in hypertension?
EYES = Hypertensive retinopathy, retinal haemorrhage, papilloedema
BRAIN = Cerebrovascular disease (stroke/TIA)
HEART = LV hypertrophy, IHD, Heart failure
KIDNEYS = Nephropathy
Explain the drug treatment for hypertension
If aged < 55 = A
If aged >55, black/African Caribbean family origin = C
If needed ….. A + C
If needed …… A + C + D
If needed …… A + C + D + further D, alpha/ beta blocker/
What causes secondary hypertension?
In 10% of patients there is a specific underlying disease is is presenting with increase BP, this is known as secondary hypertension.
- Renal disease
- Cushing’s disease
- Phaechromocytoma
- Sleep apnoea
- Primary aldosteronism
- Brain tumour/Encephalitis
- Obesity
How does cushing’s disease cause secondary hypertension?
Higher levels of glucocorticoids which facilitate sodium and H20 retention + consequently increase blood pressure and volume
How does primary aldosteronism cause secondary hypertension?
Adrenal galnds produce excess aldosterone which facilitate sodium and H20 retention + consequently increase blood pressure and volume
How does renal disease cause secondary hypertension?
In renal disease, the patient is unable to lose fluid therefore increases blood pressure/volume.
Polycystic kidney disease = an inherited condition that causes fluid to accumulate in cysts on kidneys = increased fluid retention and increased BV and BP
Glomerular disease = increased BV + BP
Renovascular hypertension is due to narrowing of the renal arteries and restricted flow to the kidneys. The kidneys assume this reduced flow is due to a decrease in blood volume/thirst and consequently retain fluid and increased BV+ BP
How does pheochromocytoma cause secondary hypertension?
Pheochromcytoma is an adrenal gland tumour which stimulates noradrenaline and adrenaline release to increased BP
How does sleep apnoea cause secondary hypertension?
Stopping and starting breathing decreases oxygen levels in the body and therefore the heart beats harder and faster to increase oxygen levels. This causes an increase in BP over night.
How does obesity cause secondary hypertension?
As the body weigh increases, the amount of circulating blood must increase too and therefore the BV and BP increase.
How does brain tumours/ encephalitis cause secondary hypertension?
The increased ICP reduced blood flow to the brain and therefore the body has to overcome this by increasing BP t ensure blood flows around the body
List 6 other causes of temporary hypertension
- Oral contraceptive pill
- NSAID’s
- Stimulants e.g. Cocaine
- Antidepressants
- Hypothyroidism
- Coarctation of the aorta
