Atrial fibrillation wavelets propagating in different directions disorganised atrial depolarisation without effective atrial contraction f waves beats /min. ventricular response is grossly irregular at beats /min. (in WPW >300/min or VF)

AF potentially serious consequences: –embolism –impaired cardiac output –increased mortality extremely common

Arch Int Med :1316 AF Annual rate of stroke at FU (mean 1.6 years) was 4.7% LA dimension not predictive but moderate to severe LV dysfunction (any visible dysfunction greater than mild global or focal hypokinesia) independently increased risk by odds ratio of 2.5

AF:stroke risk previous CVA/TIA (RR 22.5) diabetes (RR 1.7) hypertension (RR1.6) increasing age (RR 1.4/decade) CCF/IHD (RR 3.0) –one of these and annual stroke risk >4% untreated

Atrial Fibrillation Analysis of 6 randomised primary prevention trials has shown a 68% reduction in annual rate of stroke (4.5%-1.4%) reduction in mortality of 30% in the treated group annual rate of bleeding was 1.3%; major haemorrhage 0.3% and associated with age, hypertension and increased intensity of anticoagulation

Arch Int Med :1449 Meta-analysis of anticoagulant studies aspirin (325 mg) associated with 44% stroke rate reduction Warfarin about 50% more effective than aspirin for prevention of ischaemic stroke

Apirin and clopidogrel ……are they safer than warfarin in AF patients?

Connolly S. American Heart Association Scientific Sessions 2005; Nov 13-16, 2005; Dallas, TX. Vascular events and major bleeding: ACTIVE-W final results End pointClopidogrel+ ASA WarfarinRelative risk p Vascular events (%/year) Major bleeding (%/year)

AF/intensity of anticoagulation

AF considerable heterogeneity of patients with AF so treatment strategies will differ: –restoration and maintenance of SR or –control of ventricular rate and anticoagulation

Falk et al Ann Int Med :503 AF: digoxin is not the answer Cardioversion may be achieved with either electrical shock or with antiarrhythmic drugs digoxin is not effective in cardioverting patients from AF to SR

Cardioversion embolism risk 0-7% –previous embolism –prosthetic valve –mitral stenosis

AF: low risk for cardioversion less than 2/7 duration absence of thrombus on TOE <60 years no clinical risk factors

Cardioversion: high risk require 3/52 anticoagulation pre- cardioversion 4/52 after cardioversion

Management of AF cardioversion results in SR in 90% of cases SR is only maintained in 30-50% at one year class 1a, 1c and III agents increase likelihood of maintained SR from 30-50% to 50-70% at one year

Botker et al Br Heart J 1991; 65: Digoxin and heart-rate

Matsuda et al Cardiovasc Res :453 AF: digoxin is not the answer Both beta and calcium channel blocking agents control ventricular rate in AF patients at rest and on exercise but the negative inotropic and chronotropic effects may be deleterious to exercise tolerance

In chronic atrial fibrillation …..pulmonary-vein ablation restores sinus rhythm

Oral, H. et al. N Engl J Med 2006;354: Circumferential Pulmonary-Vein Ablation

Oral H et al NEJM 2006;354: Ablation and chronic AF 146 patients with refractory chronic AF were randomly assigned to pulmonary-vein ablation or to receive short-term therapy with amiodarone.

Oral, H. et al. N Engl J Med 2006;354: Percentages of Patients without Atrial Fibrillation and Atrial Flutter in the Absence of Antiarrhythmic-Drug Therapy

Rate or rhythm ….do we really need to restore and maintain sinus rhythm, or can we simply maintain heart rate control?

EP Show – December 2002 AFFIRM Atrial Fibrillation Follow-up Investigation of Rhythm Management

Inclusion criteria Wanted to focus on the elderly >65 years of age Patients where the atrial fibrillation itself was a risk for morbidity or mortality Able to tolerate at least 2 drug regimens in both treatment arms

Treatment strategies Patients were randomized to a strategy, not a specific drug regimen Pharmacological therapies: allowed any drug approved by North American regulatory authorities. Drugs could be added if they were approved during the trial Nonpharmacological therapies: allowed designated therapies once a patient failed 2 drug therapies

EP Show – December 2002 AFFIRM Mortality results N Engl J Med 2002;347:

EP Show – December 2002 AFFIRM Prevalence of warfarin Greater prevalence of warfarin use in rate- control arm Rate-control arm: >85% throughout the trial Rhythm-control arm: >70% throughout the trial N Engl J Med 2002;347:

EP Show – December 2002 AFFIRM Strokes 1727 During warfarin but INR <2.0 Event 4425After discontinuing warfarin 80 (7.1%) 77 (5.5%) Ischemic stroke Rhythm control (n=2033) Rate control (n=2027) N Engl J Med 2002;347:

AF ….other issues.

Lone AF Under age 60 without structural cardiac disease, hypertension, diabetes, coronary heart disease or thyrotoxicosis low annual risk manage off warfarin

AF: digoxin is not the answer In WPW and AF digoxin enhances conduction through the accessory pathway. It may lead to VF and death and should not be used in known or suspected WPW

Paroxysmal AF Accounts for about 65% of all AF commoner in young and in men similar stroke rates to chronic AF management should probably be similar too

Atrial Fibrillation-the elderly Median age of patients with AF is 75 the risk of both AF and haemorrhage increase with age risk of bleeding shown to be a function of intensity of anticoagulation

Atrial Fibrillation-the elderly Close control of INR is essential and should be maintained below 3 the elderly with clinical profiles indicating an increased risk of bleeding should not receive warfarin and aspirin is a reasonable compromise

Over 75 years even without additional risk factors likely to benefit from anticoagulation; care with anticoagulant monitoring

Aspirin years no clinical risk factors risk =2%/year warfarin contraindicated unreliable patient

Warfarin for…... AF risk factors for stroke good candidate for anticoagulation

Atrial fibrillation: conclusions common significant risk of stroke potential for risk reduction restoration of atrial systole desirable maintenance of sinus rhythm a challenge