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Atrial Fibrillation. Dr Nidhi Bhargava 8/10/13. Most Common sustained clinical arrhythmia Incidence rises with age- >5% over the age 65-75. Risk factors for AF. Hypertension- accounts for 14% of AF in population Heart failure Male sex Diabetes Valvular MI LVH LVSD
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Atrial Fibrillation Dr Nidhi Bhargava 8/10/13
Most Common sustained clinical arrhythmia • Incidence rises with age- >5% over the age 65-75
Risk factors for AF • Hypertension- accounts for 14% of AF in population • Heart failure • Male sex • Diabetes • Valvular • MI • LVH • LVSD • Left atrial dilatation • Lone AF- with no structural or functional heart disease- 15%
Types of AF • Paroxysmal or recurrent (intermittent and self terminating) • 35-66% of all AF cases peak prevalence 50-69yrs • At least a quarter may go progress to permanent AF • Persistent (does not terminate spontaneously but may be effectively cardioverted) • Permanent ( no longer reversible or reverses for brief interval only)
Effects of AF • Haemodynamic effects • Loss of atrial contraction and AV synchrony • Rapid ventricular rate • Irregular ventricular rate
Effects of AF • Symptoms • Palpitations • Breathlessness • Chest pain
Effects of AF • Thromboembolism • Valvular AF -more so in pts.. with MS and AF (6% per year) • Non Valvular AF- 4-5 times increased risk of stroke overall • Further increased risk if • Previous stroke or TIA (20x increased risk) • Age >65, Hypertension and diabetes • CAD, LV dysfunction and Left atrial dilatation • <65 yrs. risk 1% per annum
Effects of AF • Mortality- doubled in both sexes • Increased risk of stroke 4-5 fold increase- further increase with age from 1.5% in sixth decade to 23.5% in the ninth decade
Treatment • Restoration of sinus rhythm • Pharmacological cardioversion • Electrical cardioversion • External • Internal
Treatment • Maintenance of sinus rhythm • Drugs • DDD pacing • Ablation of AF triggers • Surgery for AF • Ventricular Rate Control • Anticoagulation
Treatment • Cardioversion (pharmacological and electrical) • Electrical cardioversion • External and Internal • External- under GA, success rate 65-90%, 200-360J • Internal- under sedation- percutaneous electrode- success rate 90% • Pharmacological cardioversion • Most effective if administered within 24 hrs. of onset • Flecainide most effective- 72-95% • Others include amiodarone , sotalol, propafenone • Less effective in chronic AF- Amiodarone most effective • At least 4 weeks of full anticoagulation • Anticoagulation to e maintained for 4 weeks after successful cardioversion
Treatment • Maintenance of Sinus rhythm • Drugs • Flecainde and Propafenone (Class 1c) • Sotalol better then propafenone • Amiodarone – most effective but multiple side effects • Beta blockers- no date available • Digoxin- no effect • Pacing • DDD pacing- reduce AF paroxysms • Continuous atrial pacing-dual site or biatrial
Treatment • Focal Ablation • Targets AF initiating foci located in proximal pulmonary veins • Radiofrequency energy delivered • Used for pts. with paroxysmal AF • Pts. with chronic AF but can be successfully cardioverted at least for few seconds • Under LA • Success rate 70% in PAF and 50% in chronic AF
Treatment • Surgery for AF-Maze operation • Ventricular rate control • AV node ablation • Drugs • Digoxin- not negative inotropic but less effective • Diltiazem, verapamil and beta blockers- more effective but negatively inotropic
Case histories • A 67 years old female with no risk factors presents with palpitations • A 77 years old male with no risk factors is found to be in AF on routine examination • A 98 years old male with AF on warfarin presents with haematuria and subsequently diagnosed with Ca bladder • A 79 year old female with AF rate 120-140/min, on warfarin and digoxin, asthmatic and has severe reaction to verapamil-treatment options • A 64 years old diabetic is in AF on routine examination