lecture 25 - pharmaceutical care in patients with atrial fibrillation of stroke

Question 1

what is the definition of atrial fibrillation?

Answer 1

supraventricular tachycardia characterised by disorganised atrial electrical activity, results in absence of significant atrial depolarisation

Question 2

what is shown on an ECG of atrial fibrillation ?

Answer 2

no p waves on the ecg. The ventricular Arte is rapid and irregular

Question 3

what are symptoms of atrial fibrillation?

Answer 3

feeling breathlessness, dizzy, palpitations, tiredness, chest discomfort and difficulty exercising

Question 4

what is used to diagnose atrial fibrillation? x5

Answer 4

ECG

Holter monitor

loop recorder

blood results

echo

Question 5

what are blood results used for?

Answer 5

to rule out any underlying condition such as
diabetes
hyperthyroidism
anaemia
renal function
infections
high cholesterol

Question 6

how is an echocardiogram used for atrial fibrillation diagnosis?

Answer 6

does not diagnose atrial fibrillation but shows damage to the heart muscle and looks for left ventricular dysfunction

Question 7

what are 2 reasons to treat atrial fibrillation?

Answer 7

alleviate symtoms

management of the complications to irregular heart rate - to reduce risk of stroke and developing heart failure

Question 8

what is a thromboembolic risk assessment ?

Answer 8

CHa2DS2-VASc score

thromboembolic risk assessment a condition when a blot clot forms in the vein ie it risk assessment for stoke ONLY when a patient has atrial fibrillation

Question 9

explain the CHA2DS2-VASc score

Answer 9

C - chronic heart failure - 1 point

H - hypertension - 1 point

A - Age (>65 or > 75 years) - 1 or 2 points

D - diabetes - 1 point

S - stroke/ transient isachemaic attack - 2 points

VA - vascular disease - 1 point

S - sex (female) - 1 point

if score is 2 or over it is a high risk group

Question 10

what are the treatment options for atrial fibrillation?

Answer 10

warfarin - vitamin K antagonists

or DOAC - direct orla anticoagulant such as direct thrombin inhibitor and factor Xa inhibitor - apixaban and edoxaban

Question 11

describe the apixaban dose for treatment of af

Answer 11

standard dose is 5mg twice a day. reduced to 2.5mg if patient is over 80 years, weight 60kg or less or serum creatinine 133 micro moles/l

Question 12

describe the edoxaban dose for treatment of af

Answer 12

standard dose is 60mg once daily

dose reduction to 30mg once daily id creatinine serum is 15-50ml/min

do not require INR checked for edoxaban

Question 13

why is anticoagulant given for life?

Answer 13

to reduce risk of stroke

Question 14

what drugs are used of rventriucalr ate control in patients with AF?

Answer 14

AV blocking drugs

Question 15

what av blocking drugs are licensed for af?

Answer 15

beta blockers eg atenolol

calcium channel blocker - verapamil

digoxin

Question 16

what patients is digoxin used in?

Answer 16

heart failure and asthmatic who cannot take beta blocker,

heart failure but only for short term use as has no nbenenfits longe term - switch to a beta blocker if possible

sedative, immobilised or elderly patients

Question 17

what is the first line treatment in AF and describe its mechanism of action

Answer 17

beta blocker - atenolol

antagonise beta-receptors, resulting in decreased conduction through the AV node, which reduces the heart rate in patients with atrial fibrillation

Question 18

what is the next line treatment in AF and what patients is it contraindicated in?

Answer 18

Non-dihydropyridine calcium channel blockers (verapamil)

reduce AV conduction by antagonising voltage gated calcium channels, decreasing intracellular calcium.
reduce left ventricular contractility via the same mechanism, and therefore contraindicated in patients with left ventricular systolic dysfunction (LVSD).

Question 18

what is digoxin used for and describe its mechanism of action

Answer 18

rate control

blocks the sodium/potassium ATPase pump.
The mechanism by which this decreases AV conduction is not clear, but is perhaps due to increased vagal tone.
Effective to reduce ventricular rates at rest but not effective during physical activity.

Question 19

what is digoxin recommended to be used in combination with and when may it be prescribed on its own?

Answer 19

Therefore, it is recommended to use digoxin in combination with a beta-blocker or non-dihydropyridine calcium channel blocker.

If prescribed on its own => only in patients not mobilising

Question 20

when is digoxin used as first line treatment in patients?

Answer 20

Digoxin is 1st line treatment in patients with acute heart failure symptoms and AF.

Question 21

what drugs are used for rhythm control - alleviate symptoms?

Answer 21

class II amiodarone and class IC flecainide

Question 22

describe how class III amiodarone works

Answer 22

act by blocking potassium channels.

effective but toxicity is a concern

The half-life is 42 days.

Inhibition of T4 and T3 entry into the peripheral tissues.
preferred in patients with LVSD

Chemical cardioversion

Question 23

describe how class IC flecainide works

Answer 23

maintain sinus rhythm or chemical cardioversion

Significant coronary artery disease is a contraindication

Flecainide can be used with a “pill-in-the-pocket” approach

Question 24

what are counselling points of flecainide pill in the pocket ?

Answer 24

What is pill in the pocket – prone to get af symptoms from time to time and doesn’t want to be on regular medicine. Common in younger males. Beta blcokers can cause erectal dysfunction. They will vet 2 tablets with flecainide. If symptoms of palpitations, then they will take 2 flecainide and go from af to sinus rhythm. Counselling required. Needs to someone nearby to help if it goes wrong.

Question 25

what are the guidelines for direct current cardio version DCCV for treating af - getting heart back in rhythm. ?

Answer 25

if haemodynamic is unstable

systolic BP is less than 90mmHg

chest pain/ heart failure symptoms

reduced consciousness levels

known onset of AF is less than 48 hours

Question 26

what is the difference between stroke and TIA?

Answer 26

stroke is a clinical syndrome characterised by sudden onset of rapidly developing focal or global neurological disturbance which alerts more than 24 hours or leads to death

Transient ischaemic attack (TIA) — transient (less than 24 hours) neurological dysfunction caused by focal brain, spinal cord, or retinal ischemia, without evidence of acute infarction

Question 27

explain ischaemic - thrombotic stroke and embolic stroke and cerebral haemorrhage.

Answer 27

thrombotic stroke - blood clot blocks flow of blood in brain and so brain really deprived of blood

embolic stroke - fatty plaque or blot clot (embolism) breaks away and flows to brain where it blocks an artery

cerebral haemorrhage - break in blood vessels (aneurysm) in brain - area of bleeding in brain

Question 28

explain lacunar, thrombotic and embolic stroke

Answer 28

small vessels, lacunar - small vessels Deep in the brain are affected

large vessels (thrombotic) - hyperlipidaemia with unstable plaque

cariogenic (embolic) - clot moves from the heart and lodges in a vessel in the brain

Question 29

what are initial complications of stroke? x6

Answer 29

Haemorrhagic transformation of ischaemic stroke.

Cerebral oedema.

Seizures.

Venous thromboembolism — pulmonary embolism has been associated with 13-25% of deaths in the early period following stroke.

Cardiac complications — cardiac complications (myocardial ischemia, congestive heart failure, atrial fibrillation, and arrhythmias) are common due to shared aetiology.

Infection — people with stroke are at increased risk of infection including aspiration pneumonia, urinary tract infection, and cellulitis from infected pressure sores.

Question 30

what are long term potential complications after stroke? x6

Answer 30

Mobility problems
Hemiparesis or hemiplegia (weakness on one side of the body)
Ataxia (lack of co-ordination of movement)
Falls —
Spasticity and contractures. Spasticity is common following stroke and can lead to discomfort, pain, difficulties for carers and restriction of activities.

Sensory problems
It has been estimated that up to 80% of people have some loss or alteration in sensations such as touch, temperature, and pain.

Continence problems
Urinary and faecal continence problems are common following stroke and can persist long-term. They can have a negative impact on mood, self-image, confidence, and rehabilitation and increase carer stress.
Urinary incontinence increases the risk of skin breakdown and can be exacerbated by constipation.

Pain — pain is common following stroke and can be due to neuronal damage from stroke or a pre-existing condition (such as osteoarthritis):

Dysphagia (difficulty in swallowing foods, fluids and saliva) occurs in 40–78% of people with stroke and is associated with aspiration pneumonia, disability and death.

Visual problems

Question 30

what are the 4 stages involved in acute stroke care?

Answer 30

1. admit ti a stroke unit - patients more likely to survive stoke, have fewer disabilities and live independent life-styles if admitted to stroke unit
2. imaging
   initial CT scan will identify if haemorrhage or clot
   CT quicker than MRI
3. swallow
   dysphagia may occur and if not identified can cause poor nutrition, pneumonia and increased disability
4. assess medicines
   stop all anticoagulation’s, thrombolytics, antipalteles and saids pending ct results

withhold all swallowing medicines

Question 31

what are complications of thrombolysis?

Answer 31

Main Side Effects
1. Intra –cerebral haemorrhage 4.2%
of these 4.2 %, 1 in 100 will die as a result.
2. Angioedema 0.7%
Bleeding-minor bleeding is common (IV site)

Anaphylaxis

Stats show the quicker the stroke is treated the better the outcome (4.5 hours window from start of symptoms)

Question 32

what drug is initially given for secondary prevention of stroke ?

Answer 32

Aspirin given on the day of admission or the following day for all patients in whom a haemorrhagic stroke, or other contraindication has been excluded

one state dose of aspirin by moth or suppository

aspirin should be avoided for 24 hours post thrombolysis as it would increase risk of bleeding

Question 33

what are antipaltelet or anticoagulants dose following secondary prevention of stroke?

Answer 33

After stat dose:
a)Patients in Sinus Rhythm
14 days aspirin 300 mg then clopidogrel 75 mg daily and then:
Clopidogrel 75mg (unlicensed in TIAs)

b) Patients in AF
Remember: x5 increased stroke risk
14 days aspirin 300 mg depending on impact of stroke and then:
Anticoagulation is usually initiated 10-14 days after
stroke
Remember also to alleviate symptoms of AF – rate control

Question 34

what do we do to blood pressure following secondary prevention of stroke

Answer 34

All patients with previous stroke or TIA should be considered for treatment regardless of BP as it reduces risk of stroke by 37%

If under 55 years old –an ACE inhibitor or anangiotensin receptor blocker (ARB).

If 55 or older or African – Caribbean origin of any age – a calcium channel blocker or thiazide

Question 35

how is cholesterol affected for the secondary prevention of stroke?

Answer 35

Atorvastatin 40 mg – 80 mg is used 1ST line

Statins should NOT be used in patients with haemorrhagic stroke unless risk of vascular event outweighs risk of haemorrhagic event.

Question 36

how is diabetes impacted for the secondary prevention of stroke ?

Answer 36

High incidence of stroke in patients with diabetes

Risk factor for stroke

Sliding scale insulin may be indicated if glucose
high on admission

Question 37

how is exercise or lifestyle effected for sonar prevention of stroke?

Answer 37

Overweight / obese increases risk of stroke
Smoking
Increased Risk of stroke by ~50%
Smoking cessation – risk returns to that of non-smoker after 5 years

Alcohol
-Effect on stroke risk controversial
-Protective effect in light/moderate drinkers
-Elevated risk in heavy alcohol consumption