MANAGEMENT OF ATRIAL FIBRILLATION

1. MANAGEMENT OF ATRIAL FIBRILLATION VINOD G V

2. Definitions • Paroxysmal AF - self-terminating, usually within 48 h, may continue for up to 7 days. • Persistent AF - when an AF episode either lasts longer than 7 days or requires termination by cardioversion. Long-standing persistent AF has lasted for ≥1 year when it is decided to adopt a rhythm control strategy. Permanent AF-DC version failed or not attempted • Recurrent AF-has had 2 or more episodes

3. “lone AF” • generally applies to young individuals under 60 y of age without clinical or echocardiographic evidence of cardiopulmonary disease including hypertension . • have a favorable prognosis with respect to thromboembolism and mortality.

5. Haemodynamics • Loss of atrial contraction • A rapid ventricular rate • An irregular ventricular rhythm • Loss of mechanical AV synchrony affects ventricular filling esp. when left ventricle has reduced compliance.

6. 3 objectives Rate control prevention of thromboembolism correction of the rhythm disturbance,

7. Type and duration of AF • Severity and type of symptoms • Associated cardiovascular disease • Patient Age • Associated medical conditions • Pharmacological and nonpharmacological therapeutic • options.

8. Rapid ventricular rate produce symptoms Tachycardia related cardiomyopathy

9. Rate control • Strict rate control: Resting HR -60-80 Moderate exercise 90-110 • Lenient HR Resting HR <100 RACE II (RAte Control Efficacy in permanent atrial fibrillation) trial did not identify a benefit of stringent rate control over lenient rate control therapy in 614 patients

11. Primary Outcomes Cardiac death CHF Stroke Systemic embolism Major bleed Syncope Sust VT Cardiac arrest Life threat compl of antiarrhythmic Pacemaker Secondary Outcomes Symptoms

16. Beta-Blockers useful in the presence of high adrenergic tone or symptomatic myocardial ischaemia • Non dihydropyridine CCB-Diltiazem,verapamil • Digoxin-effective at rest ,not during exercise

17. Rhythm control

18. Theoretical Benefit of Rhythm Control • Improved hemodynamics • Relief of symptoms • Improved exercise tolerance • Reduced risk of stroke • Avoidance of anticoagulants

19. Rhythm control • Pharmacological • Non pharmacological Cardioversion Catheter Ablation

20. Cardioversion in AF • Pharmacological • Electrical cardioversion

21. DC Cardioversion • Delivery of an electric shock synchronised with the intrinsic activity of heart by sensing the R wave • Successful cardioversion depends on Duration of AF Current density delivered to atrial myocardium

25. Joglar JA et al Am J Cardio 2000

26. Mittal S et al Ciculation 2000

27. Elhendy A et al Am J Cardio 2002

28. Pharmacological cardioversion • Simple • Less efficaious • More effective in AF <7 day duration • Problems of drug toxicity

29. AF lasting <1 wk – cardioversion -using oral flecainide, propafenone, dofetilide, and intravenous ibutilide. • For longer duration- iv dofetilide( also amiodarone and ibutilide may be useful) • Single oral dose of propafenone or flecainide – in recent onset AF (pill in the pocket)

30. 2 strategies • Oral warfarin with a therapeutic INR (2–3) for 3 to 4 weeks before cardioversion followed by continued warfarin thereafter • Transesophageal echocardiography (TEE) and heparin immediately before cardioversion followed by oral warfarin thereafter. • Left atria – stunning effect. So anticoagulation is to be continued for 4 wks

31. AF upto 7 days

32. AF >7 days

33. Pharmacological Rhytm control

34. Major Trials Comparing Rhythm Strategy and Rate Strategy Major trials include: • AFFIRM (Atrial Fibrillation Follow-Up Investigation of Rhythm Management ) • RACE (rate control versus electrical cardioversion) • PIAF (pharmacological intervention in AF) • AF-CHF Major overall findings: • Rhythm-control strategy was not superior to rate-control strategy in terms of morbidity/mortality • Appropriate choice of therapy should be based on each patient’s symptoms and disease • rate control, prevention of thromboembolism, and correction of the rhythm disturbance - these strategies are not mutually exclusive

39. AFFIRM : 5 Year Outcomes NO DIFFERENCE:Death, major bleed ,disabling stroke,cardiac arrest Sinus rhythm maintained in only 63% of rhythm control group

40. AFFIRM Trial • No survival advantage to rhythm control. • Rhythm control patients were more likely to be hospitilized with adverse drug effects. • Both groups had similar stroke risk (1% per yr) • Majority of strokes when warfarin stopped or INR subtherapeutic • Warfarin required long term even if sinus rhythm restored • Torsades, bradycardic arrest more common with rhythm control.

41. Attempts at restoration of sinus rhythm not always successful • AFFIRM Trial: only 63% of “rhythm control” group were in sinus rhythm • Antiarrhythmics used to maintain sinus rhythm associated with a 25-50% annual failure rate. • Long term anticoagulation not mandated in the “rhythm control” group • Those in afib at risk for stroke • Medications used to maintain sinus rhythm risk of proarrhythmia and other toxicity

42. Vernakalant • Acts preferentially in atria • Blocking several ion channels • Prolongation of atrial refractoriness • Rate dependent slowing of atrial conduction • Little impact on ventricular repolarization Pharmacological cardioversion of AF <7 days or <3days for patients after cardiac surgery

43. AVRO Double-blind,active-controlLed -i.v. amiodarone N=232 Vernakalantn = 116, Amiodaronen = 116 Hypertension(71.6%) ischaemic heart disease(22.4%) myocardial infarction (8.2%) heartfailure(19.8%)(NYHA I- 45.7%, NYHA54.3%) valvular heart disease, 6.9% AF 3–48 h (median 17.7 h) Time to conversion 11m Conversion to SR- 51.7% vs. 5.2% P <0.0001 Reduction in symptoms at 2 h reported by 53.4% patients in the vernakalantgroupvs. 32.8% in the Amiodarone group P = 0.0012

44. “Pill in the Pocket” strategy • Preferred in • Paroxysmal AF with no structural heart disease • Self administration of a single oral dose of drug shortly after the start of palpitations • Decrease hospital visits Propafenone 450-600mg Flecainide 200-300mg

45. Anti-arrhythmic drugs for maintaining sinus rhythm

46. Selection of specific agent depends on underlying cardiac disease

49. CATHETER ABLATION IN AF

50. Factors • Factors that trigger • Factors that perpetuate • Triggering foci of rapidly firing cells within the sleeve of atrialmyocytes extending into the pulmonary veins - shown to be the underlying mechanism of most paroxysmal AF