8. Hypertension Flashcards
What is the main cause of hypertension and what is it more commonly known as
Primary/essential hypertension (95%)
This means that hypertension has developed on its own and does not have a secondary cause
What are the main causes of secondary hypertension
mnemonic ROPE
Renal disease (most common)
Obesity
Pregnancy induced hypertension/ pre-eclampsia
Endocrine- most do but primarily consider hyperaldoesteronism (Conns syndrome)
If patients develop hypertension below the age of _____ , this is when specialist investigations should be considered in patients with a potential secondary cause
40
what are the complications of hypertension
ischemic heart disease cerebrovascular accident (stroke or haemorrhage) hypertensive retinopathy Hypertensive nephropathy heart failure premature death
NICE recommend measuring blood pressure every _____ years to screen for hypertensive but more often in which patients
5 years
more often in those with borderline for diagnosis (140/90) and every year in patients with type 2 diabetes
patients with clinic blood pressure of between what range should have 24 hour ambulatory blood pressure or home readings to confirm the diagnosis
between 140/90 and 180/120 mmHg
When you measure the blood pressure in both arms, if the difference is more than ______ then you should repeat the readings
15mmHg
Explain to the patient how they should carry out home blood pressure monitoring
o Need to make sure that you don’t smoke, have a drinking containing caffeine or exercise for 30 minutes before you take reading
o Make sure to use the same arm and rest for 5 mins before taking the reading
o For each measurement, 2 measurements are taken at least 1 minute apart and with the person seated
o BP recorded twice a day, ideally in the morning and evening
o Blood pressure recording should be taken for about 4-7 days (discard the first days readings and take an average of the rest)
What is the clinic reading and ambulatory reading for stage 1 hypertension
Clinic of above 140/90
ambulatory of above 135/85
what is the clinic reading and ambulatory reading for stage 2 hypertension
clinic of above 160/100
ambulatory of above 150/95
what is the reading for stage 3 hypertension
above 180/120
What are the red flags for hypertension
- accelerated hypertension (BP usually higher than 180/110 with signs of papilloedema and/or retinal haemorrhage)
- Suspected phaeochromocytoma (tumour of the adrenal glands) –> postural hypertension, headache, palpitations, pallor and diaphoresis ie sweating
- consider specialist investigations in people with signs and suggesting of a secondary cause of hypertension
Describe what hypertensive urgency is and what are the symptoms
this is where there is uno target organ damage
BP 180 mmHg systolic OR 110mmHg diastolic
Symptoms
- headahce
- SOB
-nosebleed
- severe anxiety
describe what hypertensive emergency is aka malignant hypertension
this is where there is target organ damage systolic of above 180 mmHg OR diastolic of above 120 mmHg but note these could be lower symptoms - chest pain - SOB -back pain -numbness/weakness -vision changes - difficulty speaking
Whilst waiting for a diagnosis of hypertension what tests would you carry out to test for end organ damage
- Urine albumin:creatinine ratio for proteinuria and dipstick for microscopic haematuria to assess for kidney damage
- Bloods for HbA1c, renal function and lipids
- fundus exam for hypertensive retinopathy
- ECG for cardiac abnormalities
What does the Qrisk3 score calculate
a persons risk of developing a heart attack or stroke over the next 10 years
NICE determine that the treatment threshold for primary prevention of CVD is above what percentage Qrisk3 score
10% or more
What is the formula for cardiac output and what is the definition
The amount of blood the heart pumps through the circulatory system in a minute
CO = HR x SV
if a patient has a HR of 70 BPM and a stroke volume of 70L what is the cardiac output
CO= HR x SV 70x70 = 4.9 L
What is the formulae for blood pressure
Cardiac output x peripheral resistance
Why does hypertension cause reduced blood flow to the kidneys and hence what does the kidneys release I response to reduced blood flow
High blood pressure can constrict and narrow the blood vessels, which eventually damages and weakens them throughout the body, including in the kidneys. The narrowing reduces blood flow.
- the kidney releases renin
Renin causes the release of aldosterone, how does this affect the blood pressure
- aldosterone increases reabsorption of Na+and therefore water which increases the blood volume
- Increasing the blood volume increases the cardiac output
How does renin release interact with angiotensinogen
- angiotensin I –> Angiotensin II by ACE enzyme from the lungs
- angiotensin II is a potent vasoconstrictor which increases the peripheral resistance
to raise the arterial pressure what does NA act on
alpha adrenergic receptors on vascular smooth muscle cells which cause them to contrict
note that there are beta-adrenergic receptors in the heart which cause increased contractility
what are baroreceptors and chemoreceptors sensitive to
baroreceptor sensitive to stretch
chemoreceptor sensitive to low O2, high CO2 and acidosis (note chemoreceptors have their own blood supply)
What is the role of aldosterone
causes increased absorption of Na+ (and therefore water) as well as secretion of K+ and H+
what happens in primary hyperaldoesteronism (aka Conns syndrome)
there is high levels of aldosterone therefore low K+ and low H+ which leads to hypokalaemia
What is the problem in Addisons disease
the adrenal glands done produce enough cortisol, aldosterone and adrenaline
