AF and Flutter

Question 1

What is AF

Answer 1

An arrhythmia where the atria do not contract in a coordinated way due the disorganised electrical impulses originating in the roots of the pulmonary veins
This uncoordinated response does prime the ventricles therefore causes cardiac output to drop
It produces an irregularly irregular heart rate at 300-600bpm

Question 2

What is the main risk with AF

Answer 2

embolic stroke

Question 3

How much can cardiac output drop by

Answer 3

10-20%

Question 4

How does AF present

Answer 4

My be asymptomatic 
May present as 
Chest pain 
palpitations 
dyspneoa
Dizziness/faintness
breathlessness

signs

• irregularly irregular pulse
• examine whole patient for causes of AF –> hyperthyroidism, listen to lungs

Question 5

What are the causes of AF

Answer 5

Cardiac

• Heart failure/ischaemia
• Hypertension
• MI
• mitral valve disease

Respiratory

• PE
• Pneumonia

Metabolic

• hyperthyroidism
• Hypokalaemia
• Hypomagnesnia

Other and drugs

• Caffiene
• Alcohol
• Post op

Question 6

How would you investigate AF

Answer 6

Bedside obs: HR, RR, BP, temp, sats 
ECG 
Bloods 
- FBC
- U+Es
- cardiac enzymes 
- TFTs

Consider Echo

Question 7

What would an ECG show in AF

Answer 7

Absent P waves

irregular QRS complexes

Question 8

How is acute AF managed

Answer 8

A-E assesment
Oxygen
IV access and bloods taken (FBC, U+Es, cardiac enzymes, TFTs)
If less than 48Hrs - Amiodarone 300mg IV over 20-60 mins and 900mg over 24hrs
If over 48hrs then
IV betablocker
IV digoxin

Question 9

How is AF managed long term

Answer 9

Rate or rhythm controlled

Rate control 
- Beta blocker 
- rate limiting Calcium channel blocker 
- if those fail then use digoxin - only if patient has sedentary lifestyle 
Then consider amiodarone

Question 10

When would you consider rhythm control over rate control

Answer 10

If the patient was young 
Symptomatic 
Has congestive cardiac failure 
Presenting for the first time with lone AF 
AF from corrected precipitant

Question 11

Why do patients with AF need to be anticoagulated before doing DC cardioversion

Answer 11

DC may dislodge a thrombi that has formed

Question 12

Why are patients with AF more likely to form thrombi

Answer 12

Stasis of the blood in the atria as they are not contracting in a coordinated way and they are able to form in the left appendage and then can be pumped into the ventricle and into systemic circulation

Question 13

In which patients can flecanide not be used

Answer 13

patients with structural heart disease

use amiodarone instead

Question 14

What does the ECG show in atrial flutter

Answer 14

Continuous atrial depolarisation e.g. ~300bpm

shows sawtooth baseline

Question 15

How is atrial flutter treated

Answer 15

Cardioversion may be indicated - however anticoagulate before
Consider amiodarone to restore rhythm and amiodarone or sotalol to maintain it

Question 16

What is used in acute AF for anticoagulation

Answer 16

Heparin until full risk assesement made
Warfarin if risk is high
use no anticoagulation if risk is not high and stable sinus rhythm returned and AF recurrence unlikely i.e no failed cardioversions, no structural heart disease, no previous recurrences

Question 17

How long should patients with AF who are having an elective cardioversion be anticoagulated for

Answer 17

3 weeks

Question 18

What is the target INR for a patient with AF on warfarin

Answer 18

2 -3

Question 19

What are the contraindications to warfarin

Answer 19

Bleeding diathesis 
Low platelets
Consistently high BP of 160/90 
Compliance issues around dosing and monitoring 
Patient choice after risks discussed

Question 20

Which drugs are an alternative to warfarin

Answer 20

NOACs

e.g. Dabigatran

Question 21

How does dabigitran work

Answer 21

Direct thrombin inhibitor