Atrial Fibrillation
Summary
Symptoms
Acute AF (<48/24)
** Rhythm for symptomatic, CCF, younger, 1st lone AF, AF from corrected precipitant (UEC)
NOTE: Use CHADS2/ CHA2DS2VASc
--END OF SUMMARY--
Symptoms
- Asymptomatic
- Palpitations/ Chest pain
- Dyspnoea
- Pre-syncope/ syncope
- Heart disease
- Electrolyte imbalance
- Irregularly irregular pulse (160-180bpm)
- Apical PR > radial PR
- S1 with variable intensity
- LVF signs
- Murmurs
- Bedside: ECG (absent P waves, irregular QRS)
- Bloods: UEC+CMP, troponin, TFT
Acute AF (<48/24)
- If very ill, cardioversion --> meds --> LMWH
- If not, treat cause --> 1st line: Verapamil/ Bisoprolol, 2nd line: Digoxin/ Amiodarone --> LMWH
- Rate control: BB/ CB --> (if fails) + digoxin* --> (if fails) change to amiodarone
- Rhythm control** --> Cardioversion/ Drug: Flecainide (no heart disease) or Amiodarone (heart disease)
** Rhythm for symptomatic, CCF, younger, 1st lone AF, AF from corrected precipitant (UEC)
NOTE: Use CHADS2/ CHA2DS2VASc
--END OF SUMMARY--
Definition
Epidemiology
9% of elderly
Most common arrhythmia
Aetiology
Pathogenesis
Atrial enlargement --> Fibrosis --> Affected electrophysiology --> repetitive focal beats/ reentrant beats --> AF
Clinical Features
Symptoms:
Signs:
Investigations
Bedside: ECG (absent P waves, irregular QRS)
Bloods: UEC+CMP (electrolyte imbalance), troponin (rule out AMI), TFT (?Hyperthyroidism)
Management
Acute AF (<48/24)
Chronic AF
*Digoxin as monotherapy only for sedentary pt
** Rhythm for symptomatic, CCF, younger, 1st lone AF, AF from corrected precipitant (UEC)
***Avoid BB if sick sinus syndrome (ie alternating between AF and bradycardia)
Complications
CHADS2:
If on Warfarin:
>/= 3: High risk - regular review
Source
Toronto Notes 2012
OHCM 9th Ed 2014
- Irregularly irregular heart rate caused by chaotic+irregular rhythm at 300-600bpm, resulting in AV node working intermittently
- Lone AF = no cause found
- Rapid AF = >100BPM, slow AF = <60BPM
Epidemiology
9% of elderly
Most common arrhythmia
Aetiology
- HF/ ischaemia
- HTN
- MI (22%)
- PE
- Mitral valve disease
- Pneumonia
- Hyperthyroidism
- Caffeine
- Alcohol
- Electrolyte (K, Mg) drop
Pathogenesis
Atrial enlargement --> Fibrosis --> Affected electrophysiology --> repetitive focal beats/ reentrant beats --> AF
Clinical Features
Symptoms:
- Asymptomatic
- Palpitations/ Chest pain
- Dyspnoea
- Pre-syncope
Signs:
- Irregularly irregular pulse
- Apical PR > radial PR
- S1 with variable intensity
- LVF signs
Investigations
Bedside: ECG (absent P waves, irregular QRS)
Bloods: UEC+CMP (electrolyte imbalance), troponin (rule out AMI), TFT (?Hyperthyroidism)
Management
Acute AF (<48/24)
- (If very ill) O2 --> UEC --> Em cardioversion/ drug cardioversion --> (not very ill) treat cause --> [verapamil (1st line)/ bisoprolol; digoxin/amiodarone (2nd line)] - control ventricular rate --> LMWH
Chronic AF
- Rate control: BB/ CB --> (if fails) + digoxin* --> (if fails) change to amiodarone --> Warfarin
- Rhythm control**(cardioversion): Echo (for thrombus) --> >4/52 on sotalol/ amiodarone --> cardioversion --> Warfarin
- Rhythm control (drug): Flecainide (no heart disease)/ Amiodarone (heart disease) --> Warfarin
*Digoxin as monotherapy only for sedentary pt
** Rhythm for symptomatic, CCF, younger, 1st lone AF, AF from corrected precipitant (UEC)
***Avoid BB if sick sinus syndrome (ie alternating between AF and bradycardia)
Complications
- Decreased cardiac output
- Stroke (due stasis --> thrombus)
CHADS2:
- C = CCF 1pt
- H = H/T 1pt
- A = Age >/=75 1pt
- D = Diabetes 1pt
- S = Prior TIA/Stroke 2pts
- 0 = low risk (2%/year = nothing/ aspirin), 1 = moderate risk (3%/yr = aspirin/ anticoags), 2-6 = high risk (4-18%/yr --> anticoags)
If on Warfarin:
- Hypertension
- Abnormal renal and liver function
- Stroke
- Bleeding
- Labile INRs
- Elderly (>65)
- Drugs or alcohol
>/= 3: High risk - regular review
Source
Toronto Notes 2012
OHCM 9th Ed 2014