3.1 Hypertension And Heart Failure

Question 1

How do you calculate mean arterial pressure?.

Answer 1

CO x TPR.

Question 2

What is resistance to flow inversely proportional to?

Answer 2

Inversely proportional to the radius (to the 4th power)

So, Vacoconstiction = increased peripheral resistance = increased BP

Question 3

What can hyperinsulinemia and hyperglycaemia lead to?

Answer 3

Endothelial dysfunction and reactive oxygen species, decreased NO

Question 4

Why do you need to treat Hypertension?

Answer 4

Precursor to cardiovascular disease

Question 5

Define hypertension

Answer 5

An elevation in blood pressure that is associated with an increase in risk of some harm

Question 6

What are some causes of hypertension?

Answer 6

White coat/clinic
Isolated systolic/diastolic (only one is raised)
Prehypertensive
Secondary

Question 7

How do you diagnose and treat hypertension?

Answer 7

• screening sessions
• increase public awareness of risk factors
• reliable diagnoses based on clinical guidelines
• promote appropriate lifestyle changes to limit risk
• regulate monitoring and refinement of medication.

Question 8

What are the clinical methods of diagnoses of hypertension?

Answer 8

Measure BP with patient sat relaxed with a supported arm

Measurements in both arms should be similar, within 20mmHg

Severe = medical emergency, send to A&E

Patient management follows diagnoses

Cardiovascular risk and wend organ damage should be assessed whilst waiting for HT conformation

Question 9

Normal BP?

Answer 9

<120/80 mmHg

Question 10

Stage 1 hypertension measuring ?

Answer 10

140/90 mmHg or higher

Home - 135/80 mmHg

Question 11

Stage 2 hypertension BP?

Answer 11

160/100 mmHg or higher

Home 150/95

Question 12

Severe hypertension bp?

Answer 12

SYSTOLIC IS 180 mmHg or higher or diastolic is 110 mmHg or higher

Question 13

What is prehypertension?

Answer 13

Elevated BP below stage 1 diagnoses with no end organ damage that can be treated in the first instance with lifestyle changes

Question 14

What can lifestyle changes can treat elevated bp in prehypertension?

Answer 14

Regular exercise
Modified health/balanced diet
Reduction in stress and increased relaxation
Limited/reduced alcohol intake
Discourage excessive caffeine consumption
Smoking cessation
Reduction in dietary sodium

Question 15

What are some primary HT therapeutic agents?

Answer 15

ACE inhibitors
Angiotensin receptor blockers
Calcium channel blockers
Diuretics

Question 16

Where does ACE and Ang 2 act?

Answer 16

Luminal surface of capillary endothelial cells, predominantly in the lungs

Catalysts conversion of Ang 1 to And 2 which is a vasoconstrictor

Ang 2 acts through AT1 and AT2 receptors

Question 17

Name 4 ACE inhibitors.

Answer 17

Captopril
Enalapril
Lisinopril
Ramipril

Question 18

Why do ace inhibitors cause a dry cough?

Answer 18

ACE substrate = bradykinin

If ACE is inhibited, get a build up of bradykinin = dry cough

Question 19

What side affects are associated with ACE inhibitors?

Answer 19

Dry cough
Angioedema
Renal failure
Hyperkalaemia

Question 20

How do angiotensin 2 receptor blockers work?

Answer 20

Block AT1 receptors which carry out majority of angiotensin 2 functions (unlike AT2 receptor)

Directly targeting AT1 receptors means they’re more effective at inhibiting Ang 2 mediated vasoconstriction

Question 21

What side effects do you get with ang 2 receptor antagonists?

Answer 21

Renal failure and hyperkalaemia

No dry cough as no effect on bradykinin

Question 22

Name 4 ang 2 receptor antagonists

Answer 22

Losartan
Candesartan
Eprosartan
Irbesartan

Question 23

What do calcium channel blockers target?

Answer 23

Calcium inhibiated smooth muscle contraction

There are three classes that interact with different sites on a1 subunit of VOCC selectivity for vascular smooth muscle cells or myocardium

Question 24

What are the three classes of calcium channel blockers?

Answer 24

• Dihydropyridine

Non dihydropyridine
- Phenylalkamines and benzothiazapines

Question 25

How do dihydropyridine CCB work and what are their properties?

Answer 25

More selective for peripheral vasculature, show little chronological or inotropic effect - first line CBB for HT - good oral absorption - protein bound - metabolised by liver

Question 26

Name an example of a dihydropyridine CBB and name its adverse effects.

Answer 26

Amolodipine is an example Adverse effects - sympathetic NS activation = tachycardia (rare) - palpitation - flushing/sweating/throbbing headache - oedema

Question 27

What is the mode of phenylalkylamines CBB?

Answer 27

Depresses SA node and slows AV conduction, negative inotropy Prolongs the AP and effective refractory period Impede ca transport across myocardial and vascular smooth muscle cell membrane

Question 28

Give an example of a phenylalkylamine and give it’s adverse effects

Answer 28

Verapamil Effects include - constipation - bradycardia - negative inotrope = can worsen heart failure, especially with a beta blocker

Question 29

What are the properties of benzothiazapines CBB ?

Answer 29

Impede ca transport across ca and smooth muscle cell membrane Prolong AP

Question 30

Name a benzothiazapines CCB and give its adverse effects

Answer 30

Diltiazem Effects - risk of bradycardia - negative inotropic effect less than verapamil = can worsen heart failure

Question 31

What are some adverse effects of thiazides? Name an example

Answer 31

Example = bendroflumethiazide Effects - hypokalaemia - increased urea and Uris acid levels - impaired glucose tolerance especially with beta blockers - cholesterol and triglycerides levels increase - activates RAAS

Question 32

Why is there no point in giving ARBs to a low renin patient?

Answer 32

Low activity in RAAS system anyway so no point in targeting it for treatment.

Question 33

In pregnancy or a hypertensive emergency, what centrally acting drugs would you use?

Answer 33

Labetalol reduced sympathetic outflow

Question 34

What is spironolactone?

Answer 34

Mineralocorticoid/ aldosterone receptor antagonists

Question 35

What is amiloride?

Answer 35

A K+ sparing diuretic acting on distal tubule

Question 36

What is the effect of alpha adrenoreceptors blocking agents? Name an example.

Answer 36

Doxazosin is an example They antagonise the contractile effects of noradrenaline on vascular smooth muscle Reduced peripheral vascular resistance Benign effect on plasma lipids/glucose Safe in renal disease Adverse effects - postural hypotension - headache and fatigue - oedema

Question 37

What is the effect of beta adrenoreceptors blockers? Name an example

Answer 37

Bisoprolol is an example Decreased sympathetic tone by blocking Nad and reducing myocardial contraction = decreased CO = decreased renin secretion

Question 38

What are the adverse effects of beta adrenoreceptors blockers?

Answer 38

Adverse effects - bronchoconstriction so don’t give in asthma, COPD and 2nd/3rd degree heart block - mask tachycardia = sign of insulin induced hyperglycaemia = caution in diabeties - lethargy and impaired concentration - reduced excersise tolerance - bradycardia - raynauds E.g bisoprolol

Question 39

What are the aims of heart failure treatment?

Answer 39

Manage symptoms Increase exercise tolerance Decreased mortality Address arrhythmia NB: furosemide is typically used in most patients for symptoms but has little impact on survival

Question 40

How can ace inhibitors and ARBs treat heart failure?

Answer 40

In LV dysfunction Low initial dose reduces risk of sudden rapid fall in BP, especially in patients already taking diuretics If ACE inhibitors not tolerated, use ARB as alternative If not working can use both together Make sure you monitor renal function

Question 41

Why may a patient be given spironolactone with a ACE inhibitor or diuretic?

Answer 41

It maximises their effects. NB: spironolactone is a aldosterone/mineralocorticoid receptor antagonist

Question 42

What is the role of B adrenoreceptors antagonists?

Answer 42

Recommended for all patients with stable clinical heart failure Introduced once ACE inhibitor or ARB therapy is initiated Blunts sympathetic influences especially on HR = slower HR = longer diastolic filling period = better filling = more output May stabilise electrical conduction reducing arrhythmia May also blunt circulating RAAS by working on renin but probably minor since already on ACE Low initial dose which may cause transient worsening of symptoms