CR Week 1

Question 1

1) Define the term cardiac output. (1 mark)

Answer 1

Cardiac output = volume of blood pumped out per ventricle per minute.

Question 2

(2) Aside from cardiac output, name the other major physiological factor that determines mean arterial pressure (MAP). (1 mark)

Answer 2

• Total peripheral resistance (TPR) (systemic vascular resistance, SVR)

[Note: CVP is usually at or near 0 mmHg and is largely ignored (except when pathological)].

Question 3

(3) Blood pressure is usually measured indirectly by taking which two readings? State the units used. (3 marks)

Answer 3

1) Systolic pressure (top value), maximum (systolic – achieved during left ventricular contraction). (1 mark)
(2) Diastolic pressure (bottom value), minimum (diastolic – achieved during ventricular filling). (1 mark)
- in mmHg (the unit for measuring blood pressure). (1 mark)

For example: 125/90 mmHg.

Question 4

(4) State two risk factors for hypertension that are mentioned in the scenario. (1 mark)

Answer 4

½ mark for each

• Family history
• Age - older you are, the more likely you are to get high blood pressure.
• Gender - men are more likely to get high blood pressure than women are.
• Smoking
• Being overweight
• Not doing enough exercise

Question 5

(5) Describe two drugs that could be prescribed to the patient in the scenario to lower blood pressure. Briefly outline their mechanism of action. (4 marks)

Answer 5

1. ACE inhibitors (½ mark) - inhibit the actions of angiotensin-converting enzyme (ACE) and the production of angiotensin II (½ mark) to cause vasodilation (½ mark) – reduces total peripheral resistance (TPR) (½ mark).

2. Angiotensin II receptor blockers (½ mark) – These drugs selectively inhibit angiotensin II via competitive antagonism of the angiotensin II receptors (½ mark), to cause vasodilation (½ mark) – reduces total peripheral resistance (TPR) (½ mark).

3. Thiazides and related compounds (½ mark) – act to inhibit sodium reabsorption at the beginning of the distal convoluted tubule (½ mark) and hence cause diuresis (increase in water excretion) (½ mark) – note (not fully understood but) reduces blood volume/cardiac output in the short term (½ mark).

Question 6

what is systolic and diastolic presure?

Answer 6

systolic pressure – the pressure when your heart pushes blood out

diastolic pressure – the pressure when your heart rests between beats

Question 7

how do you calculate CO? [1]
how do you calculate BP? [1]

Answer 7

Cardiac output (L/min) = Stroke volume (L) x Heart rate (BPM)

Cardiac output x Peripheral resistance = BP

Question 8

how do you calculate mean arterial presssure? [1]

Answer 8

Mean arterial pressure = Cardiac output x vascular resistance (how hard it is to pump blood through vascular). More fluid you have causes a higher BP.

Question 9

define hypertension

Answer 9

Hypertension is persistently raised arterial blood pressure.

Question 10

what are the following?

• Primary/ Essential hypertension?
• Malignant hypertension?
• Secondary hypertension?
• White-coat hypertension?
• Masked hypertension?

Answer 10

•Primary/ Essential hypertension: Abnormally high BP, not due to a chronic medical condition (~95% cases)

•Malignant hypertension: Rapid rise in BP, resulting in vascular damage

•Secondary hypertension: High BP secondary to a chronic condition (~5%)

•White-coat hypertension: High BP in clinic, Low/normal out of clinic

•Masked hypertension: Low/normal BP in clinic, high out of clinic

Question 11

how do you measure BP? [2]

Answer 11

• Sphygmomanometer
• Ambulatory Blood Pressure: 24 hour period

Question 12

which factors affect BP?

Answer 12

• Cardiac output: HR x Stroke volume
• Peripheral Vascular Resistance
• Volume of circulating blood
• Viscosity of blood
• Elasticity of vessel walls (compliance)

Question 13

which hormones modulate BP in hormonal response to hypertension? [3]

which neutrotransmitter modualtes neuronal to hypertension? [1]

what is the effect of both of above?

Answer 13

Hormonal: Antidiuretic Hormone (ADH), Aldosterone, Angiotensin II
-Modulates: heart rate, inotropy, total peripheral resistance and bloodflow between tissue

Neuronal: Noradrenaline
- Modulates sodium and water retention, total peripheral resistance and bloodflow between tissue

Question 14

what are risk factors for hypertension?

Answer 14

• Age — blood pressure tends to rise with advancing age.
• Sex — Up to about 65 years, women tend to have a lower blood pressure than men. Between 65 to 74 years of age, women tend to have a higher blood pressure.
• Ethnicity —Black African and Black Caribbean origin (more likely)
• Genetic factors —40% of variability in blood pressure may be explained by genetic factors.
• Social deprivation — people from the most deprived areas in England are 30% more likely to have hypertension than those from the least deprived.
• Lifestyle — smoking, excessive alcohol consumption, excess dietary salt, obesity, and lack of physical activity are associated with hypertension.
• Anxiety and emotional stress —increased adrenaline and cortisol levels.

Question 15

what is hypertension a risk factor for? [2]

Answer 15

•NUMBER 1 RISK FACTOR FOR CARDIOVASCULAR DISEASE = Myocardial Infarction (MI), Stroke

Question 17

why are eyes affected with hypertension?

Answer 17

-Hypertension = raised BP

-Raised pressure within brain (intracranially)

-Raised pressure or volume to retinal vessels

-Vessels within eye are small/delicate and fragile, especially susceptible to pressure changes.

• Haemorrhage manifests (dot and blot) as microbleeds can occur.
• Other factors can cause angiogenesis within the eye (such as VEGF),in diabetes mellitus = new vessel formation = vessel fragile = burst easily.

Question 18

why undertake a urine test when have hypertension? - what are you checking for? [3]

Answer 18

• Proteinuria (protein in urine)?
• Haematuria (blood in urine) (gross vs fine)?
• Glycosuria (glucose in urine?!)

Question 19

define stroke & the two types that occur

Answer 19

• Interruption to blood flow to part of brain, causing ischemia (insufficient blood flow)and hypoxia (insufficient oxygen)
• Generally caused by:

oInfarction (artery blockage)

oHaemorrhage (Rupture of an aneurysm)

Question 20

explain how RAAS influences BP
what do hypertensive drugs do to RAAS?

Answer 20

1. Renin-Angiotensin-Aldosterone system (RAAS)
   
   1. - Most drugs aim to block RAAS
   2. - Kidney senses low BP and renin is released from the juxtaglomerular cells
   3. - Renin converts angiotensinogen to angiotensin I
   4. - ACE from the lungs converts angiotensin I to angiotensin II
   5. - Angiotensin II (extremely potent vasoconstrictor) stimulates aldosterone release resulting in increased Na+ and thus water reabsorption which leads to increased blood volume and thus blood pressure
   6. - Thus angiotensin II increases peripheral resistance and inhibitors target this
      2.

Question 21

name two diseases that could cause 2ry hypertension [1]

Answer 21

Endocrine:
Primary aldosteronism (increasingly recognised as a major cause of hypertension, see notes )
Phaeochromocytoma
Cushing’s syndrome (see notes)
Acromegaly (see notes)

Renal
Renovascular disease (e.g. atheromatous, fibromuscular dysplasia)
Intrinsic renal disease (e.g. CKD, AKI, glomerulonephritis)

Drugs
Glucocorticoids
Oral contraceptives
SSRIs
NSAIDs
EPO

Question 22

name 2 signs and 2 sypmtopms of hypertension [2]

Answer 22

Hypertension is typically asymptomatic. However, signs and symptoms may reflect underlying end-organ damage or a potential secondary cause.

Symptoms:
Palpitations
Angina
Headaches
Blurred vision
New neurology (e.g. limb weakness, paraesthesia)

Signs
New neurology (e.g. limb weakness, paraesthesia)
Retinopathy
Cardiomegaly
Arrhythmias
Proteinuria

Question 23

describe how you conduct ambulatory BP monitoring
describe how you conduct home blood pressure monitoring

Answer 23

If clinic BP is 140/90 mmHg or higher, ABPM is used to confirm the diagnosis (except in Stage 3 hypertension, in which immediate treatment is initiated).

With ABPM, at least two measurements an hour are taken during the patient’s usual waking hours (e.g. 8 am - 10 pm). The average value of these measurements is used to confirm the diagnosis. Alternative strategies can be considered including doing a full 24-hour assessment that includes nocturnal readings.

Home blood pressure monitoring (HBPM) can be used. This involves taking two measurements a day (morning & evening) over a period of at least 4 days, ideally 7. At each recording, two consecutive measurements should be taken at least 1 minute apart when the person is seated. The readings on the first day are discarded and the average of the following readings are used to confirm a diagnosis of hypertension.

Question 24

describe white coat hypertension

Answer 24

This refers to an elevated blood pressure above the normal range in a clinical setting (e.g. GP appointment, hospital outpatients). It is defined as a discrepancy of > 20/10 mmHg between clinic and average ABPM/HBPM

In white coat hypertension, blood pressure is thought to be artificially elevated due to the stress of being in a clinical settin​

Question 25

how do you treat hypertension?

who goes onto immediate treatment?

Answer 25

Modifiable risk factors

Lifestyle modification & patient education are important in treating hypertension.
Offer advice that targets the patient’s modifiable risk factors.
Discourage excessive caffeine and alcohol, if appropriate offer smoking cessation advice.
Consider the need for anti-platelets or a statin.

Whom to treat

If clinic BP < 140/90 mmHg or ABPM < 135/85 mmHg, check BP at least every 5 years or more often if clinic BP close to 140/90 mmHg. If evidence of end-organ damage, consider other causes.

Antihypertensive drug therapy is initiated in patients:

Aged < 80 years with stage 1 hypertension and with one of the following; end organ damage, cardiovascular disease, renal disease, diabetes or 10-year cardiovascular risk ≥10%.

of any age with stage 2 hypertension

of any age with stage 3 hypertension (consider immediate treatment)

Consider treatment in patients > 80 years old with stage 1 hypertension if clinic BP is > 150/90 mmHg. However, take into account frailty and co-morbidities. Patients < 60 years with stage 1 hypertension can be considered for antihypertensive therapy even if the 10-year cardiovascular risk < 10%.

Question 26

what is differential treatment plans for HT?

Answer 26

if under 55: ACE inhibs

if over 55: Ca2+ blockers

A = ACE-inhibitor / Angiotensin receptor blocker (ARB)
C = Calcium channel blocker (CCB)
D = Thiazide-like diuretic
T2DM = Type 2 diabetes mellitus