Atrial Fibrillation/Flutter

Question 1

Define atrial fibrillation

Answer 1

characterised by rapid, chaotic and ineffective atrial electrical conduction. Often subdivided into:

Permanent

Persistent

Paroxysmal

Question 2

Permanent atrial fibrillation

Answer 2

continuous and lasts longer than 12 months

Question 3

Persistent atrial fibrillation

Answer 3

If your irregular heartbeat episode lasts for more than a week

Question 4

Paroxysmal atrial fibrillation

Answer 4

occurs when a rapid, erratic heart rate begins suddenly and then stops on its own within 7 days

Question 5

Explain the aetiology and risk factors of atrial fibrillation

Answer 5

There may be no identifiable cause

Secondary causes lead to an abnormal atrial electrical pathway that results in AF

Question 6

Systemic Causes

Answer 6

Thyrotoxicosis- excess thyrid hormone

Hypertension

Pneumonia

Alcohol

Question 7

Heart Causes

Answer 7

Mitral valve disease

Ischaemic heart disease

Rheumatic heart disease

Cardiomyopathy

Pericarditis

Sick sinus syndrome

Atrial myxoma

Question 8

Lung causes

Answer 8

Bronchial carcinoma

PE

Question 9

Summarise the epidemiology of atrial fibrillation

Answer 9

VERY COMMON in the elderly

Present in 5% of those > 65 years

May be paroxysmal

Question 10

Recognise the presenting symptoms of atrial fibrillation

Answer 10

Often ASYMPTOMATIC

Palpitations

Syncope (if low output)

Symptoms of the cause of AF

Question 11

Recognise the signs of atrial fibrillation on physical examination

Answer 11

Irregularly irregular pulse

Difference in apical beat and radial pulse

Check for signs of thyroid disease and valvular disease

Question 12

Identify appropriate investigations for atrial fibrillation

Answer 12

ECG
Bloods
Echocardiogram

Question 13

ECG

Answer 13

Uneven baseline with absent p waves

Irregular intervals between QRS complexes

Atrial flutter = saw-tooth

Question 14

Bloods

Answer 14

Cardiac enzymes

TFT- thyroid function

Lipid profile

U&Es, Mg2+ and Ca2+

Because there is increased risk of digoxin toxicity with hypokalaemia, hypomagnesaemia and hypercalcaemia tf

Question 15

Echocardiogram

Answer 15

Mitral valve disease

Left atrial dilatation

Left ventricular dysfunction

Structural abnormalities

Question 16

Generate a management plan for atrial fibrillation

Answer 16

First and foremost, try to treat any reversible causes (e.g. thyrotoxicosis, chest infection)

There are TWO main components to AF management:

RHYTHM CONTROL
RATE CONTROL

Question 17

RHYTHM CONTROL

Answer 17

If > 48 hrs since onset of AF
- Anticoagulate for 3-4 weeks before attempting cardioversion

If < 48 hrs since onset of AF
-DC cardioversion (2 x 100 J, 1 x 200 J)

Chemical cardioversion: flecainide or amiodarone

NOTE: flecainide is contraindicated if there is a history of ischaemic heart disease

Question 18

Prophylaxis against AF

Answer 18

Sotalol

Amiodarone

Flecainide

Consider pill-in-the-pocket (single dose of a cardioverting drug (e.g. flecainide) for patients with paroxysmal AF) strategy for suitable patients

Question 19

RATE CONTROL

Answer 19

Chronic (Permanent) AF

Control ventricular rate with:

Digoxin

Verapamil

Beta-blockers

Aim for ventricular rate ~ 90 bpm

Question 20

STROKE RISK STRATIFICATION

Answer 20

LOW RISK patients can be managed with aspirin

HIGH RISK patients require anticoagulation with warfarin

This is based on the CHADS-Vasc Score

Question 21

Risk factors include

Answer 21

Previous thromboembolic event

Age > 75 yrs

Hypertension

Diabetes

Vascular disease

Valvular disease

Heart failure

Impaired left ventricular function

Question 22

Identify the possible complications of atrial fibrillation

Answer 22

THROMBOEMBOLISM

Embolic stroke risk of 4% per year

Risk is increased with left atrial enlargement or left ventricular dysfunction

Worsening of existing heart failure

Question 23

Summarise the prognosis for patients with atrial fibrillation

Answer 23

Chronic AF in a diseased heart does not usually return to sinus rhythm