Atrial Fibrillation Flashcards
What is the definition of Atrial fibrillation?
Disorganised electrical activity in the atria leads to irregular ventricular rhythm
What are common causes of Atrial Fibrillation?
(6)
- S – Sepsis
- M – Mitral valve pathology (stenosis or regurgitation)
- I – Ischaemic heart disease
- T – Thyrotoxicosis
- H – Hypertension
What is the paroxysmal AF?
2 or more episodes, self terminating lasting <48 hours
Paroxysmal AF - Investigations
Patients with a normal ECG and suspected paroxysmal atrial fibrillation can have further investigations with:
* 24-hour ambulatory ECG (Holter monitor)
* Cardiac event recorder lasting 1-2 weeks
Paroxysmal AF - Management
- Flecainide - ‘Pill in pocket approach’
Indication : infrequent episodes without structural heart disease
* Pill taken when symptoms start
Valvular AF : Definition
AF with
* Significant mitral stenosis
* Mechanical heart valve
Assumed that valvular pathology has led to AF
Valvular AF : Management
Cardiologist referral
What is the definition of persistent AF?
continuous AF, lasting for >7 days
What are the symptoms of AF?
- Palpitation
- Dyspnoea
- Chest pain
- Syncope
- Irregularly irregular pulse
What are the ECG features of AF?
- Absent P waves
- Narrow QRS complex tachycardia
- Irregularly irregular ventricular rhythm
What is the first line management of AF?
Rate control;
1. Beta blocker
or
Rate limiting calcium channel blocker
1. Combinition of non rate limiting CCB + Beta blocker
What is the management of Heart failure with Atrial Fibrillation?
Digoxin
What are the indications for rhythm control in AF?
(5)
- Haemodynamic instability secondary to AF
- AF with a reversible cause
- Heart failure primarily caused by AF
- New onset AF < 48 hours
- Atrial flutter whose condition is considered suitable for ablation strategy
What are the options for rhythm control?
Cardioversion
1. Immediate cardioversion if Sx onset < 48 hours
1. Electrical cardioversion
2. Chemical cardioversion
* Flecainide - no structural heart disease
* Amiodorone - structural heart disease
- Delayed Cardioversion
1. Electric cardioversion after 3 weeks of anticoagulation
2. Long-term rhythm control using medications
- First-line : Beta blockers
- Second-line - Dronedarone
-for maintaining normal rhythm where patients have had successful cardioversion - Amiodarone is useful in patients with heart failure or left ventricular dysfunction
What is the management of a patient who presents <48 hours and clinically stable?
- TOE and rhythm control (if suitable)
Or - Rate control
What is the management of a patient who presents >48 hours and clinically stable?
- Rate control
or - If considered for rhythm control
* 2. - 3 weeks minimum of anticoagulation prior to cardioversion
What is the role of Flecainide in chemical cardioversion?
- Indication : paroxysmal AF
- Contraindication : cannot be used in patients with structural heart condition
What is the role of Amiodorone in chemical cardioversion?
Indication : if coexisting HF
Amiodorone : MOA
** Indication**
* class III antiarrhythmic agent
* used in the treatment of atrial, nodal and ventricular tachycardias.
MOA : blocking potassium channels which inhibits repolarisation and hence prolongs the action potential.
What are the side effects of Amiodorone? (5)
- Photosensitivity
- Slate-grey pigmentation
- Hepatoxicity
- Hypo/Hyperthyroidism
- Pulmonary fibrosis
- Lengthening of the QT interval
- p450 inhibitor
- Thrombophlebitis at injection side
Monitoring of Amiodorone
- TFT, LFT, U&E, CXR prior to treatment
- TFT, LFT every 6 months
What is management of AF in a clinically unstable patient?
- Cardioversion
* ECHO to r/o thrombus
* AF has just started and no options to cardiovert - give IV amiodorone
What does CHADSVASC stand for?
- C ongestive heart failure
- Hypertension
- Age > 75 years
* 65 -74 years - Diabetes
- Prior Stroke, TIA or Thromboembolism
- Vascular disease - Ischaemic heart disease and Peripheral arterial disease
- Sex (Female)
What is the role of a CHADSVASC score?
(3)
- Score >1 in males or >2 in females suggests need for anticoagulation
- If CHASVASC suggests no need for anticoagulation - Transthoracic echo must be done to exclude valvular heart disease
- Valvular heart diease is an absolute indication for anticoagulation
What does ORBIT stand for?
Older age > 75 years
**R **educed haemoglobin/anaemia (Hb <130 or Hb <120 in females
Bleeding history
eGFR<60 or renal dysfuction
Treatment with antiplatelet agents
What is the role of ORBIT?
Helps to assess bleeding risk on anticoagulants
AF : Anticoagulation
Long term stroke prevention
First line : DOAC - Apixaban
2. Warfarin
AF : Post stroke anticoagulation
- Post TIA : start anticoagulation immediately
- Post Stroke - commences after 2 weeks
Investigation : Palpitations
First line
1. ECG
2. Bloods : TFT, U+Es, FBC
Second line - exclude episodic arrhythmia
1. Holter monitoring for 24 hours or more
Third line
1. External/Implantable loop recorder\
