5. AF

Question 1

what is atrial fibrillation?

Answer 1

heart condition that causes an irregular and abnormally fast heart rate.

Question 2

what is normal heart beat range at rest?

Answer 2

60-100bpm at rest

Question 3

what are the causes/risk factors for AF ?

Cardiovascular diseases

Answer 3

Hypertension
Heart failure
Ischemic heart disease
Mitral valve disease
Congenital heart disease
Coronary heart disease
Pericardial disease
cardiomyopathy

Question 4

what are the causes/risk factors for AF ?

pulmonary conditions

Answer 4

Pulmonary embolism
Pneumonia (common)
Bronchial Carcinoma
Covid
Lung cancer
COPD

Question 5

what are the causes/risk factors for AF ?

(other then cardiovascular and pulmonary)

Answer 5

Age
Obesity
T2DM
Overconsumption of alcohol
Hyperthyroidism → thyrotoxicosis
Overconsumption of caffeine (stimulants)
Physical stress due to surgery (post-op)
Atherosclerosis
Sepsis
Electrolyte disturbances Mg2+
Smoking
sleep apnoea
Genetic factors/family history
chronic kidney disease, CKD

Question 6

A patient presents with palpitations

what tests should you order?

Answer 6

ECG
might need 24 hour one to pick up episodes of AF

bloods

could also do an echocardiogram to see any structural heart disease

Question 7

how does an AF ECG present?

Answer 7

No P waves, irregular baseline
Irregular QRS

Question 8

blood test:

what specific tests are done?

Answer 8

testing to find underlying causes of AF + to see if safe to go on medication

U+Es for renal dysfunction

TFTs for hyperthyroidism

LFTs for alcoholism and contraindications with medication

CMP (calcium,magnesium,phosphate) for electrolyte disturbances

glucose for T2DM

Question 9

describe the pathophysiology of AF

Answer 9

• cells in the atria are stressed (by risk factors)
• leads to tissue heterogeneity (cells start taking on different electrical properties eg. some can conduct faster than others)
• Leads to unpredictable conduction in the atria.
• the random elective impulses firing off muscle in the atria override the natural pacemaker
• Atria quiver randomly and only partially contract

Haphazard and random impulses pass through to the ventricles causing irregular ventricular contractions with varying force

Question 10

what are the different types of AF?

Answer 10

Paroxysmal AF – AF comes and goes, tissue still healthy, usually within 2 days goes back to normal heart rate and rhythm

Persistent AF – Lasts over a week without self-terminating. cells have undergone fibrosis

Permanent AF – Long term, heartbeat beat does not return back to normal even after treatment

Question 11

symptoms of AF

Answer 11

palpitations in chest (thumping)

General fatigue (irregular contractions delivers blood less effectively to tissues)

Dizziness
Shortness of breath
Weakness
asymptomatic

Question 12

what is the main complications of AF?

Answer 12

major risk of stroke

if palpations continue, stagnant blood in atria can clot, travel to brain and lodge

(other complications: quality of life reduced as can’t exercise much, angina, HF)

Question 13

what are the treatment options for AF? (4 categories)

Answer 13

rate control treatment

rhythm control treatment

ablation

medication to decrease risk of clots and strokes

Question 14

the treatment options for AF

• what medication is used to control heart rate?

Answer 14

Beta blockers and Calcium channel blockers to Interfere with electrical impulses

Question 15

the treatment options for AF

• what method is used to control heart rhythm ?

and what medication can also be taken for rhythm

Answer 15

cardioversion

• give heart an electric shock

Medication to convert heart rhythm eg. amiodarone, Flecainide

Question 16

the treatment options for AF

• what its ablation?

Answer 16

Pass a long thin catheter into chambers of heart and destroy tiny sections of tissue (using radio frequency) that are responsible for irregular impulses

Question 17

AF can cause serious strokes

what tool is used to assess the risk of stroke in an AF patient?

Answer 17

CHA2DS2-VASc risk score

Question 18

CHA2DS2-VASc risk score

• what does it CHA2DS2-VASc stand for? what questions does it ask

Answer 18

Congestive heart failure (1)
Hypertension (1)
Aged over 75 (2)
Diabetes (1)
stroke history (2)
Vascular disease (1)
Aged 65-74 (1)
Sex female is (1) men (0)

Question 19

CHA2DS2-VASc risk score

what score means treatment for risk of stroke is needed?

Answer 19

2 or above

Question 20

how is risk of stroke in AF patients treated?

Answer 20

anticoagulants

• aspirin
• warfarin
• DOACs

Question 21

what are DOACs ?

Answer 21

direct-acting oral anticoagulants

eg. Dabigatran,
Apixaban,

Question 22

why are DOACs now preferred over warfarin?

Answer 22

effective and carry a lower risk of bleeding into the brain

Have fewer interactions with other drugs or food (no special diet needed)

Need less blood monitoring (patient doesn’t need to come in for as many tests, less adjustments needed)

Question 23

what tool is used to asses risk of major bleeding?

Use in adult patients with atrial fibrillation, to assess risk of major bleeding with anticoagulation (for stroke prevention)

Answer 23

ORBIT score

Question 24

what’s a pitfall of the ORBIT score calculator?

Answer 24

does not take into account choice of anticoagulant.

Question 25

what are the risk factors that ORBIT score evaluates ?

Answer 25

AGE - older then 75

reduced haemoglobin or history of anameia

bleeding history

insufficient kidney function

are they on antiplatlet treatment

Question 26

why is it important to know if a patient has reduce haemoglobin or anaemia when thinking of putting them on anticoagulants ?

Answer 26

need to know if they have any bleeding or haemorrhages eg. in brain or GI tract

because it you gave anticoagulant that would dangerously exacerbate and cause fatal bleeding

( 2 major risks of anticoagulants =GI bleed andbrain haemorrhage )

Question 27

what tests could you order when assessing a patients ORBIT score ?

Answer 27

GFR - for kidney function

FBC - for haemoglobin