ATRIAL FIBRILLATION

1. ATRIAL FIBRILLATION • An overview by: Matt Hall • Preceptor: Dr Lester Mercuur

2. Acute Management of AF: • A three-part approach to the acute management of AF should be considered: • Appropriate control of the ventricular rate. • The need for, proper timing of, and the appropriate method for the • restoration of sinus rhythm. • The need for anticoagulationto prevent thrombo-embolism.

3. Order of Algorithm: • Haemodynamic stability • Assess state of hydration • Ventricular Rate Control • Clinical category of AF • Risk-stratifying the cardioversion decision • Anticoagulation considerations • Disposition decisions

4. Introduction • Most common sustained arrhythmia • More prevalent in men and with increasing age • Overall prevalence of AF is 1%. 70% are at least 65 years old and 45% are over 75 • Prevalence ranges from 0.1% in adults <55 to 9%in those >80 • AF uncommon in infants and children, almost always occurring with structural heart disease • Accounts for >5% cardiac admissions

6. Classification • LONE AF:AF without structural heart disease • PAROXYSMAL AF: Self terminating AF in which the episodes of AF last <7 days (usually <24hrs) and may be recurrent • PERSISTENT AF: Not self terminating and last >7 days • PERMANENT AF: AF lasting >1 year and cardioversion has failed or not been attempted

7. Etiology: Cardiac • Hypertension (1.5x) • Coronary heart disease (6-10%) • Rheumatic heart disease (16-70%) • CHF (10-30%) • Cardiomyopathy (10-28%) • Myocarditis • Post cardiac sx (30-60%) • Pericarditis • Congenital heart disease

8. Etiology: Non Cardiac • Hyperthyroidism (20-25%) • Pulmonary embolism (10-14%) • Obstructive sleep apnea • Noncardiac surgery (4.1%) • Alcohol (60% binge drinkers-”holiday heart”) • Caffeine • Hypothermia • Medications (theophylline)

11. Symptoms and Signs • Palpitations • Fatigue • Presyncope/syncope • Dyspnea/Chest Pain • Neurologic Deficit • Irregularly irregular HR • Absent a wave in JVP • Variable S1 • Murmur

12. Evaluation • History and Physical: Define symptoms Clinical type Onset of discovery of AF Frequency/duration of AF episodes Precipitating Causes Modes of termination Response to drug therapy Presence of heart disease/reversible cause

13. Evaluation con’t • ECG: Verify presence of AF Identify LVH Pre-excitation BBB Prior MI P wave duration and morphology Measure intervals RR,QRS, QT

15. AF with pre-excitation

16. AF with pre-excitation

17. AF with pre-existing BBB

18. Pre-excitation: Varying QRS width and morphology Existing BBB: Identical QRS morphology Differences:

19. Evaluation con’t • Laboratory:CBC INR/PTT Electrolytes Creatinine TSH • CXR • Echocardiogram • Additional: TEE, Holter, Stress test, Cardiac Catheterization, EPS

20. Acute Management of AF: • A three-part approach to the acute management of AF should be considered: • Appropriate control of the ventricular rate. • The need for, proper timing of, and the appropriate method for the • restoration of sinus rhythm. • The need for anticoagulationto prevent thrombo-embolism.

23. Favours rate control Persistent AF Recurrent AF Less Symptomatic >65 years old Hypertension No Hx CHF Previous antiarrythmic drug failure Patient preference Favours Rhythm Control Paroxysmal AF First episode AF More symptomatic <65 years old No hypertension Hx of CHF No previous failure of antiarrythmic drugs Patient preference RATE VS RHYTHM CONTROL

24. Order of Algorithm: • Haemodynamic stability • Assess state of hydration • Ventricular Rate Control • Clinical category of AF • Risk-stratifying the cardioversion decision • Anticoagulation considerations • Disposition decisions

27. Ventricular rate control: • Beta-Blockers • Calcium Channel Blockers • Digoxin • (Amiodarone)

34. WHICH ONE?? • Beta Blockers High adrenergictone (eg post-op AF) Good choice if ventricular response increases excessively during exercise Exercise induced angina Setting of acute MI or Heart Failure Thyrotoxicosis • Calcium Channel Blockers No structural heart disease COPD

35. Which One?? Digoxin Usually ineffective alone (NOT 1st Line) Synergistic with other drugs LV Dysfunction +/- CHF Amiodarone Effective for rate and maintenance of sinus rhythm after cardioversion (but at what cost)

41. Acute Management of AF: • A three-part approach to the acute management of AF should be considered: • Appropriate control of the ventricular rate. • The need for, proper timing of, and the appropriate method for the • restoration of sinus rhythm. • The need for anticoagulationto prevent thrombo-embolism.

42. The need for cardioversion:- Clinical category A wide clinical spectrum exists: • - Asymptomatic to life-threatening • - Paroxysmal vs. chronic/permanent AF • - Normal heart vs. Diseased heart • Risk of stroke

43. The need for cardioversion:- Considerations The frequency of the paroxysms of AF; the severity of the associated symptoms, and the degree of underlying heart disease all need to be considered when determining the need to restore and maintain sinus rhythm.

44. The need for cardioversion: AF Spectrum Diseased heart with poor LV function Normal heart Infrequent episodes with severe symptoms Frequent asymptomatic paroxysms Paroxysmal Persistent/Permanent

45. The need for cardioversion: • An attempt at cardioversion is reasonable with: • lone AF (< 65 years with structurally normal hearts) • first episode/ new onset AF • patients who are very symptomatic during AF despite adequate ventricular rate control • patients with infrequent symptomatic paroxysmal atrial fibrillation.

46. The need for cardioversion: Patients with minimal symptoms; and in whom factors have been identified which make cardioversion and maintenance of sinus rhythm less likely, may benefit from ventricular rate control and anticoagulation alone.

47. Need for Urgent Cardioversion • Ischemic Chest Pain • Acute MI • Hypotension • Pulmonary Edema • Syncope

48. The timing of cardioversion: Key to the timing of cardioversion is the risk of thrombo-embolism.

49. The timing of cardioversion: • Factors associated with increased thromboembolic risk: • AF > 48 hours in duration or unknown duration. • Valvular heart disease – particularly mitral valve disease • Significant LV dysfunction (LVEF < 40%) or • clinical heart failure • Previous CVA/TIA/peripheral arterial embolism • Hyperthyroidism • Atrial Septal Defect (even if repaired)