AF Flashcards
definition
Irregular atrial contraction caused by chaotic impulses
Classically caused by multiple waves of electrical impulses leading to fragmentation of the normal coordinated electrical activity in the atria causing independent contraction leading to fibrillation
characteristics on a ECG
- Irregularly irregular rhythm
- Absent P waves - no coordination in atrial activity
- Irregular fibrillating baseline
Epidemiology
Most common sustained cardiac arrhythmia
Aetiology
Mrs SMITH
- Sepsis
- Mitral valve pathology - stenosis or regurgitation
- Ischaemic heart disease
- Thyrotoxicosis
- Hypertension
Aetiology cardiac
Hypertension
Ischaemic heart disease
Valvular heart disease
Myocardial infarction
Cardiomyopathy
aetiology Non cardiac
Respiratory
COPD, pneumonia, PE
Endocrine
Hyperthyroidism (everything goes faster), diabetes mellitus
Acute infections
Electrolyte imbalances
Hypokalaemia, hypomagnesaemia, hyponatraemia
Drugs
Bronco dilators, thyroxine
Lifestyle factors
Alcohol, excessive caffeine, obesity
signs
Irregularly irregular pulse
Absent ‘a’ wave on JVP: corresponds to atrial contraction
Tachycardia
Hypotension
Features of heart failure: bibasal crackles, raised JVP, peripheral oedema
Symptoms
Palpitations (heart beating out of chest)
Chest pain
SOB
Dizziness (as inadequate blood reaching the brain)
gold standard
Gold standard:
Ambulatory ECG monitoring - able to pick up paroxysmal episodes that wouldn’t be seen on a 12 lead
24 hour
48 hour
7 day
Loop recorder - 3 years
other tests
bloods
echo
Causes of irregularly irregular pulses
Premature beats - ectopic
Atrial flutter with variable block
Other atrial tachyarrhythmias
reasons of management
rate controll, rhythm controll, prevention
Rate control - first line strategy
- BB first line (not in asthma or hypoT)
- CCB - diliazem, verapamil (not in HF)
- digoxin - needs monitoring, risk of toxicity, only for those who are sedentary
Rhythm control
- Amiodarone - drug for patients with structural heart disease
- Flecainide - used In paroxysmal AF
- Beta blockers
DC cardioversion
- immediate - If the AF has been present for less than 48 hours or they are severely haemodynamically unstable
- delayed cardioversion - If the AF has been present for more than 48 hours and they are stable
Patient should be anti-coagulated for minimum of 3 weeks prior
catheter ablation
- new
- essentially damages atria tissue to prevent electrical transmission
Prevention of thromboembolic events
first line - DOACS:
Apixaban
Rivaroxaban
warfarin - valvae AF
LMWH - patients who cant tolerate it orally
CHA2DS2-VASc
assess risk of stroke
DOACs are offered as first line
Warfarin is used if DOACs are not suitable
Scores of 2 and above are recommended anticoagulation
ORBIT
Risk tool looking to identify patients at risk of a major bleeding event on anticoagulation
Score of:
4-7 = -3 high risk
3 = medium risk
0-2 = -2 low risk
cardiac complications
Heart failure
Tachycardia-induced cardiomyopathy
Ischaemia
Sudden cardiac arrest
non-cardiac complications
Thromboembolic events: stroke, TIA, mesenteric ischaemia, ischaemic limb
Collapse
Bleeding events (anticoagulation)
presented with AF >48 hours getting cardioversion
should be anticoagulated for 3 weeks before using eg apixoban
mitral stenosis
Rheumatic fever 95% of cases
AF common association
diastolic
apex tap
at what point do you prescribe rate control
HR 90+
when can you do cardioversion
only <48hrs or you anticoag for 3 weeks before and 2 weeks after
what CHA2D score requires anticoag
female - 2
male - 1
if patient comes in high HR low BP
electrocardioversion
seemingly most common non-cardiac cause of AF
alcohol
pill in pocket drug
Flecainide
why does an apical to radial pulse defect occur
not all atrial impulses (palpable at the apex) are mechanically conducted to the ventricles (palpable as a peripheral pulse)
CHA2D score of 0 but valvar condition
still anticoag
all patients with valve condition should be anticoagulated
acute / new onset management <48hrs
- fleicanide - no structural defects
- amiodarone - structural defects
electrical cardioversion with 4 weeks of anticoag after
new onset stable onset >48 hours
rate control only
rate control with BB, dilitazem or digoxin
chronic AF management
1st line:
BB - bisoprolol
CCB - diliazem
2nd line:
dual therapy
digoxin - non-paryoxsmal
when is rhythm control given in chronic cases
- AF secondary to reversable cause
- heart failure caused by AF
- new onset AF
must have
- <48hrs
- 3 weeks anticoag
- TOE to exclude thrombus
rhythm control drugs and when each is used
flecainide:
- pill in pocket
- young people
- structurally normal heart
amiadrone:
- rate and rhythm
- lots of side effects
- older sedatory patients
satolol:
- last resort
- BB + K channel blocker
antiCoag in AF
DOAC - first line
suffix aban
warfarin - for valavr AF
LMWH - patient who cant tolerate it orally
