17. Hypertension; Pathophysiology, Presentation and Investigation Flashcards
Is hypertension world’s number 1 cause of preventable morbidity and mortality?
yes
What is hypertension ranked number 1 in the Uk for?
number 1 preventable cause of premature mortality and morbidity
How big does the rise have to be in mmHg to cause significant increase in mortality risk in patients?
2mmHg rise in BP (not that much)
How does 2mmHg rise in BP affect mortality risk from IDH (ischaemic heart disease) and mortality risk from stroke
- 7% increase risk in mortality from IDH
- 10% increase risk in mortality from stroke
40% of strokes are due to BP greater than what?
> 140mmHg
What is the main complication of hypertension?
end-organ damage
Which body regions suffer from end-organ damage due to stroke? (5)
- Brain
- Eye
- Blood vessels
- Kidneys
- Heart
What can brain end-organ damage from hypertension cause? (3)
- haemorrhage
- stroke
- cognitive decline
What can eye end-organ damage from hypertension cause? (1)
-retinopathy
What can blood vessel end-organ damage from hypertension cause? (1)
- peripheral vascular disease
What can kidney end-organ damage from hypertension cause? (4)
- renal failure
- dialysis
- transplantation
- proteinuria
What can heart end-organ damage from hypertension cause? (4)
- left ventricular hypertrophy (LVH)
- chronic heart disease (CHD)
- congestive heart failure (CHF); unable to keep up with its demands
- Myocardial Infarction (MI)
When does BP mainly fluctuate?
during the day
What type of variable is BP?
continous variable
What 2 main factors cause fluctuations in BP during the day?
- physical stress
2. mental stress
Define hypertension.(arbitral definition)
Blood pressure above which the benefits of treatments outweigh the risks in terms of morbidity and mortality (abnormally high BP)
What 2 main factors affect BP normality range?
- age
2. ethnicity (people in s. Pacific seem to have smaller BP than people in Western countries)
Does stroke risk increase with increasing hypertension?
Yes (and cardiovascular)
Is the relationship between BP with stroke or coronary heart disease more linear? What does it mean?
coronary heart disease and BP more linear; it means small changes in pressures can greatly increase stroke risk since heart disease relationship is more linear
What is the “optimum” blood pressure?
120/80 - 140/90
What are clinical values for stage 1 hypertension? (clinical BP and ABPM)
- clinical BP 140/90mmHg or higher
- ABPM daytime average 135/85mmHg or higher
What is ambulatory blood pressure monitoring? (ABPM)
Measure of BP at regular intervals (~30 times in a day to give a more accurate representation of average BP)
What are clinical values for stage 2 hypertension? (clinical BP, and ABPM)
- clinical BP is 160/100mmHg or higher
- ABPM daytime average is 150/95mmHg or higher
What are clinical values for severe hypertension? (clinical systolic and diastolic BP)
- systolic is 180mmHg or higher
OR - diastolic is 110mmHg or higher
What are 2 types of hypertension and what do they mean?
- Primary hypertension; no cause found
2. Secondary hypertension; cause found
What type of hypertension do most people have?
Primary hypertension (95%)
What percentage of people have secondary hypertension? (known cause)
only around 5-10%
What 3 conditions often cause secondary hypertension?
- chronic renal disease
- renal artery stenosis
- endocrine disease
What common endocrine disease cause secondary hypertension? (4)
- Cushing’s syndrome
- Conn’s syndrome
- Phaecochromocytoma
- GRA;Glucocorticoid remediable aldosteronism
What is Cushing’s syndrome?
excess ACTH production and cortisol
What is Conn’s syndrome?
excess aldosterone produced
What is phaecochromocytoma?
rare tumour of adrenal land producing abnormal norepinethrine and epinethrine levels
What is GRA?
Glucocorticoid remediable aldosteronism; aldosterone synthase hyperactivity
To what extent is hypertension responsible for all worldwide deaths?
> 20% responsible for all deaths globally
What is the link between risk factors and chances of stroke or MI due to hypertension?
the more risk factors are added together, the greater the chances of hypertension and CV disease
What are the most common morbidity risk factors for hypertension? (6)
- cigarette smoking
- diabetes mellitus
- renal disease
- male
5.hyperlipidaemia (including high cholesterol) - previous MI or stroke
- left ventricular hypertrophy
(…+low fitness)
What risk factors double the risk of CV disease and hypertension? (2)
- being male
- left ventricular hypertrophy
What risk factor adds 2010 mmHg on average to the BP?
cigarette smoking
What risk factor increases chances of MI 5-30 times? (MASSIVE risk)
diabetes mellitus
What integrated system are prime contributors to blood pressure? (2)
- cardiac output (stroke volume and heart rate)
2. peripheral vascular resistance
What can drug therapy be used on to regulate hypertension? (2)
- cardiac output (stroke volume and heart rate)
2. peripheral vascular resistance
What effect does activation of sympathetic system have on BP?
- increases heart rate (reflex tachycardia)
- vasoconstriction so increase in TPR
- increase cardiac output
THEREFORE BP INCREASES
How can action of activated sympathetic system be described?
short-acting (flight or fight), very rapid and accounts for second to second blood pressure
What will happen if sympathetic system is overactivated?
BP will remain high and will be maintained at high levels
What hormone system is used in long-term control of BP?
renin-angiotensin-aldosterone system (RAAS)
What is RAAS responsible for? (3)
- maintenance of Na balance (conserves salt and water for survival)
- control of blood volume
- control of blood pressure
Why are people who drink more likely to become hypertensive?
- alcohol makes body retain more Na in body as treshold increases for Na retaining
- less Na excreted in urine
- leads to hypertension