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Atrial Fibrillation

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Atrial Fibrillation

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Disorganized electrical activity in atria- most common sustained cardiac arrythmia. paroxysmal atrial fibrillation-Episodes lasting longer than 30 seconds but less than 7 days ( often < 48 hrs ) that are self terminating and recurrent. persistent AF is Episodes lasting > 7 days → spontaneous termination unlikely to occur after this time. Permanent AF-AF that fails to terminate using cardioversion Terminated but relapses within 24 hrs Longstanding AF→ + 1 yr , cardioversion not attempted or indicated. lone AF-Lone AF → term used to identify AF in younger patients ( < 60 ) without structural heart dis , who are at low risk of thromboembolism

causes of AF-common Coronary artery dis Hypertension Valvular heart disease LV failure ( any cause ) HOCM. reversible-Alcohol binge Pneumonia Hyperthyroidism Acute MI Acute pericarditis Myocarditis Exacerbation of pulmonary dis PE Cardiac surgery

Complications of AF-Stroke and thromboembolism
◙ 5 times ↑ risk of stroke and thromboembolism
◙ stroke severity ↑↑ when is associated with AF
◙ peripheral thromboembolism
 Heart failure
◙ commonly associated with AF
◙ ↓ Cardiac output → pushes compromised ventricle into failure
 Tachycardia- induced cardiomyopathy and critical ischaemia
 Reduced quality of life.

Suspect AF if irregular pulse with or without-Breathlessness Palpitations chest discomfort Syncope or dizziness ↓ exercise tolerance , malaise , or polyuria Stroke , TIA or Heart failure 
( possible complications of AF ). Arrange ECG in all .ECG with AF will show-Irregularly irregular rhythm No P waves Absence of isolectric baseline Variable ventricular rate often 160-180 bpm Ventricular complexes look normal unless there is ventricular conduction defect

ECG normal but PAF suspected-24 hr ambulatory ECG monitor
◙ suspected asymptomatic episodes of PAF
◙ symptomatic episodes < 24 hr apart Event recorder ECG → if symptomatic episodes > 24 hrs apart 7 -day Holter monitor

Emergency-AF associated with any of the following


 Rapid pulse > 150 bpm Low BP – systolic bp < 90 Loss of consciousness Severe dizziness Ongoing chest pain Increasing breathlessness Stroke , TIA or acute heart failure- arrange emergency hospital admission

Assess signs and symptoms- Cardiac causes- as
○ hypertension
○ valvular heart disease
○ heart failure
○ IHD Respiratory causes- such as
○ chest infections
○ pulmonary embolism
○ lung cancer Systemic causes- as
○ excessive alcohol intake
○ thyrotoxicosis
○ electrolyte depletion
○ infections
○ diabetes

ECG-Review ECG for an underlying cause – eg old Myocardial infarction. Tests and investigations TFT , FBC , U/E , Bl urea , Ca , Mg and Glucose
 Tranthoracic echocardiogram – not essential only needed if
 
○ underlying structural heart disease suspected – eg heart murmur
○ functional heart disease – such as heart failure which will influence their subsequent management
 CXR
Pre-excitation syndrome such as WPW Valvular heart disease associated with AF Suspected heart failure who have previously has an MI Suspected heart failure- refer cardiology

Offer rate control-Offer a beta blocker or a rate limiting Calcium channel blocker Do not prescribe sotalol for rate control Consider Digoxin monotherapy for sedantary people with non-paroxysmal AF F/U in one week If symptoms , heart rate and or BP are not controlled on max drug dose consider
○ combination with any 2 of the following
- beta blocker , Digoxin or Diltiazem
- seek specialist advice before prescribing Diltiazem with a beta blocker Symptoms not controlled with combination rx- refer within 4 weeks

refer cardioversion-New onset AF AF has a reversible cause Heart failure → caused or worsened by AF Atrial flutter and suitable for ablation Rhythm control ↑ suitable – clinical judgment.AF-Presenting acutely with 
Non-life Threatening HD instability-onset within 48 hrs-Offer rate control or REFER
 MAU for immediate cardioversion

Without anticoagulation treatment
Onset more than 48 hrs-Start rate control Rx If Cardioversion indicated- START ANTICOAGULATION Minimum 3 weeks on therapeutic anticoagulation before Cardioversion

CHA2DS2VASc SCORE TOOL- 
stroke risk assessment-Assess bleeding risk using HAS-BLED score

Score >= 3 caution required- seek specialist adv.Anticoagulation treatment reduces the risk of stroke by 2/3rds
 For most people benefit of AC outweighs the risk of bleeding
 Falls risk → offer anticoagulation as risk of serious bleeds caused by falling is very small.If HAS-BLED score identifies modifiable risk factors as
 Uncontrolled hypertension Aspirin or NSAID usage Alcohol consumption.Offer Warfarin or NOACS based on
 Licensed indications Contraindications Cautions Person’s choice.If anticoagulation contraindicated
 Combination of Aspirin and Clopidogrel Do not prescribe aspirin or Clopidogrel alone.NOACS first line choice alongside warfarin. Low dose 
aspirin alone
 does not have a place in 
management 



References
 The management of Atrial fibrillation : summary of updated NICE guidance BMJ 2014;348:g3655 Atrial fibrillation:management Clinical guideline CG180 June 2014 NICE Pathways atrial fibrillation 2016 ESC Guidelines for the management of atrial fibrillation developed in collboration with EACTS European Heart Journal (2016) 37, 2893-2962 Medscape Atrial Fibrillation Lawrence Rosenthal et al Jan 2016 Oxford Handbook of Cardiology- Atrial Fibrillation CKS NHS Atrial Fibrillation Stroke prevention in atrial fibrillation : can we do better Br J Gen Pract 2016 ; 66 (643)

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