Antiarrhythmics

1. Antiarrhythmics Poisons with occasionally beneficial side effects

2. The Plan • Normal Rhythm Physiology • Antiarrhythmic Characteristics • Common Arrhythmias • Cases

3. SA AV

4. What Kind of Channels? Ca++ What kind of Channels? Na+/ K+ ! Na+ / K+ Na+ depolarize K+ repolarize What kind of Channels? Ca++ What Kind of Channels? SA AV

5. Class I – Sodium Channel blockers • Ia Quinidine, procainamide, disopyramide • Ib - Lidocaine Lidocaine easier to use quickly, less proarrhythmic • Ic – Flecainide, Propafenone More effective, more proarrhythmic

6. Class I • Effect on SA node • Effect on AV node • Effect on Conduction / Automaticity • Used for: Converting and maintaining atrial and ventricular arrhythmias

7. CAST • Cardiac Arrhythmia Suppression Trial

8. Class II: Beta Blockers Valium for the Heart

9. Class I I • Effect on SA node • Effect on AV node • Effect on Conduction / Automaticity • AND…. • Used for A. Fib rate control , SVT and adjunct for ventricular arrhythmias

10. Kyle Baker

11. Flashback: What was the CAST trial?

12. Class III: K+ Channel Blockers

13. Class I I I • Effect on SA node • Effect on AV node • Effect on Conduction / Automaticity • Effect on Refractory Period • Used for Atrial (low dose) & Ventricular (higher dose)arrhythmia conversion and maintenance

14. d-Class III l-Beta Blocker • Class I Na+ blockade • Alpha and Beta blockade • Class III Predominates • Calcium blockade Class III: K+ Channel Blockers • Sotalol • Ibutilide • Dofetilide • Amiodarone • Sotalol • Sotalol • Amiodarone

15. Class I I I - Sotalol • Effect on SA node • Effect on AV node • Effect on Conduction / Automaticity • Effect on Refractory Period

16. Class I I I - Amiodarone • EVERYTHINGSkip Side Effects and Drug Interactions. We’ll come back.

17. Class IV: Calcium Channel Blockers • Verapamil • Diltiazem • Dihydropyridines

18. Class I V • Effect on SA node • Effect on AV node • Effect on Conduction / Automaticity • Effect on Refractory Period • Used for A. Fib rate control and SVT

19. “Others” • Digoxin • Vagal Side Effect • Slows SA and AV Node (A.Fib Rate Control) • Problem: It can be overridden by sympathetic stimulation • Adenosine • Slows S-A and A-V node • Lasts minutes • Vasodilates • SE: Chest tightness, tingling, apprehension, hypotension

21. Which node is the pacemaker

23. What does the AV node do?

25. Name a calcium blocker that would not be used in A.Fib

26. HOW ARE WE DOING? What was the muddiest point?

27. Common Arrhythmias

28. Atrial Fibrillation

29. 300 to 600 /Minute Atrial Fibrillation Usually 2:1 or 3:1 Irregularly Irregular SA AV

30. http://www.tist.org/tist/aboutus/origins.php Rate Rhythm ?

31. Normal Sinus Rhythm A. Fib rate=250 A Fib rate= 100 http://www.learntheecg.com/ekg_strips

32. A. Fib: Rate vs. Rhythm • Two Options for Chronic A.Fib management • Maintain Normal Sinus Rhythm • Control Ventricular Rate • Double blind Trial to Compare • 21.3% vs 23.8% mortality with more hospitalizations in rhythm control group.

33. A. Fib: Rate vs. Rhythm • Equal Mortality • Rate control much less toxicity and trouble than rhythm control • However, Rate control does require warfarin (more later)

34. What is Rate control in A.Fib

35. What is Rhythm control in A.Fib

36. A. Fib: Rate vs. Rhythm • If you decide to do Rhythm anyway

37. Acute Conversion Options: • Propafenone (Rhythmol)1x 600mg oral dose • Ibutilide 1mg IV over 10 minutes MRx1 (proarrhythmic) • Amiodarone (various IV regimens) • Dofetilide (requires documented training TdP )

38. How do you recognize “hemodynamically unstable”?

39. Acute Conversion of A Fib • Torsades de Pointes is always a risk • Perhaps lowest risk with amiodarone

40. Torsades caused by other drugs • Tricyclics • Erythromycin • TMP/SMX • Haldol and other antipsychotics? • Quinine • Moxifloxacin

41. Rate vs. Rhythm • Chronic Rhythm Control Drugs • Amiodarone • Propafenone • Class 1a

42. Rate vs. Rhythm • Rate Control Drugs • Beta Blockers • Calcium Blockers (Non-) • Digoxin • NOT ADENOSINE • Why?

43. Atrial Fibrllation Cookbook • Disclaimers • Recommendation 1: Rate control preferred

44. Atrial Fibrllation Cookbook • Recommendation 2: Anticoagulate almost everyone (more on that in a minute)

45. Atrial Fibrllation Cookbook • Recommendation 3: Rate control drugs: • atenolol, • metoprolol, • diltiazem, • verapamil • (drugs listed alphabetically by class). • Digoxin is a second line agent

46. Why is digoxin second line?

47. Atrial Fibrllation Cookbook • Recommendation 4: For those patients who elect to undergo acute cardioversion • Shock or Poison

48. Atrial Fibrllation Cookbook • Recommendation 5: Do a trans-esophageal echo to rule out a clot OR anticoagulate three weeks prior to cardioversion.

49. Atrial Fibrllation Cookbook • Recommendation 6: In a selected group of patients whose quality of life is compromised by atrial fibrillation, the recommended pharmacologic agents for rhythm maintenance are amiodarone, disopyramide, propafenone, and sotalol (drugs listed in alphabetical order). The choice of agent predominantly depends on specific risk of side effects based on patient characteristics.

50. Atrial Fibrllation • If you don’t die of ventricular tachycardia, what is the next worst thing caused by A. Fib? • Why?