Ahmad Hersi Consultant Electrophysiologist Assistant Professor

1. Dysrhythmias Ahmad Hersi Consultant Electrophysiologist Assistant Professor

2. Sinus Tachycardia • Atrial Tachycardia • Atrial Flutter • Atrial Fibrillation • AVRT • AVNRT • Junctional Tachycardia • Ventricular Tachycardia (VT) • Ventricular Fibrillation (VF) • Torsade de point • Polymorphic VT

3. Atrial fibrillation accounts for 1/3 of all patient discharges with arrhythmia as principal diagnosis. • 6% PSVT • 6% PVCs • 18% Unspecified 2% VF • 4% Atrial Flutter • 9% SSS • 34% Atrial Fibrillation • 8% Conduction Disease • 10% VT • 3% SCD Data source: Baily D. J Am Coll Cardiol. 1992;19(3):41A.

4. Outline Atrial FibrillationDescription • Chaotic and disorganized atrial activity • Irregular heartbeat • Can be paroxysmal, persistent or permanent (chronic) • Most common sustained arrhythmia • Can be symptomatic or asymptomatic • Incidence increases with age

5. Atrial Fibrillation Demographics by Age U.S. populationx 1000 Population with AFx 1000 Population withatrial fibrillation 30,000 20,000 10,000 0 500 400 300 200 100 0 U.S. population <5 5-9 10-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80-84 85-89 90-94 >95 Age, yr Adapted from Feinberg WM. Arch Intern Med. 1995;155:469-473.

6. Atrial Fibrillation • Common and age-dependent 2 - 4% over age 60 • Significant risk of stroke 4% per year (Framingham Study) • High risk of embolism with cardioversion

7. Incidence of AF • The Framingham Study 1982, New England Journal of Medicine • Annual Incidence 0.1% Per Year

8. Atrial Fibrillation: Causes • Cardiac • Non-cardiac • “Lone” atrial fibrillation

9. Atrial Fibrillation: Cardiac Causes • Hypertensive heart disease • Ischemic heart disease • Valvular heart disease • Rheumatic: mitral stenosis • Non-rheumatic: aortic stenosis, mitral regurgitation • Pericarditis • Cardiac tumors: atrial myxoma • Sick sinus syndrome • Cardiomyopathy • Hypertrophic • Idiopathic dilated (? cause vs. effect) • Post-coronary bypass surgery

10. Atrial Fibrillation: Non-Cardiac Causes • Pulmonary • COPD • Pneumonia • Pulmonary embolism • Metabolic • Thyroid disease: hyperthyroidism • Electrolyte disorder • Toxic: alcohol (‘holiday heart’ syndrome)

11. “Lone” Atrial Fibrillation • Absence of identifiable cardiovascular, pulmonary, or associated systemicdisease • Approximately 0.8 - 2.0% of patients with atrial fibrillation (Framingham Study)1 • In one series of patients undergoing electrical cardioversion, 10% had lone AF.2 1 Brand FN. JAMA. 1985;254(24):3449-3453.2 Van Gelder IC. Am J Cardiol. 1991;68:41-46.

12. Forms of AF • Paroxysmal • Paroxysmal lasting less than 48 hours, transient • Persistent • An episode of AF lasting greater than 48 hours, which can still be cardioverted to sinus rhythm • Permanent • Inability of pharmacologic or non-pharmacologic methods to restore sinus rhythm

13. Symptoms • Palpitations • Presyncope • Fatigue • Chest pain • Dyspnea • Syncope

14. Work-up • EKG • ECHO • TFT • 24 h Holter • Others…..

15. ECG Recognition • Atrial Rate: > 300 bpm • Rhythm: Irregular • Ventricular Rate: Variable • Dependent upon: • AV node conduction properties • Sympathetic and parasympathetic ton • Recognition: Absence of P waves

16. Atrial Fibrillation: Clinical Problems • Embolism and stroke (presumably due to LA clot) • Acute hospitalization with onset of symptom • Congestive heart failure • Loss of AV synchrony • Loss of atrial “kick” • Rate-related cardiomyopathy due to rapid ventricular response • Rate-related atrial myopathy and dilatation • Chronic symptoms and reduced sense of well-being

17. Management Strategies • Prevention of Thromboembolis • Rate control • Restoration of sinus rhythm

18. Therapeutic Approaches to Atrial Fibrillation • Anticoagulation • Antiarrhythmic suppression • Control of ventricular response • Pharmacologic • Catheter modification/ablation of AV node • Curative procedures • Surgery (maze) • Catheter ablation

19. Prevention of Thromboembolis

20. Atrial Fibrillation and Stroke • Risk: 5 - 8% per year in high-risk patients • Anticoagulant therapy is clearly indicated and beneficial in rheumatic atrial fibrillation. • In non-rheumatic atrial fibrillation, major randomized trials have provided useful guidelines for identifying and treating patients at risk.

21. Predictors of Thromboembolic Risk in Atrial Fibrillation • Congestive Heart Failure • Hypertension • Age ≥75 years • Diabetes • Stroke or TIA CHADS2

22. CHADS2 Score and Risk of Stroke JAMA 2001;285:2864

23. Restoration of sinus rhythm

24. Antiarrhythmic Drugs to SuppressAtrial Fibrillation • Class I agents • IA: quinidine, procainamide, disopyramide • IC: flecainide, propafenone • Class III agents • amiodarone, sotalol

25. Timing of Cardioversion for Atrial Fibrillation • Chronic 1 month coumadin  cardioversion (CV) • Uncertain duration Stable  1 month coumadin  CV Unstable  TEE  CV • Acute no clot CV  coumadin Heparin  TEE coumadin  repeat TEE  CV clot

26. Rate control

27. Control of Ventricular Rate in Atrial Fibrillation • Digoxin • Calcium channel blockers Verapamil, diltiazem • Beta blockers

28. Sinus Tachycardia (ST)

29. Fever Volume depletion Anemia Sepsis (due to profound vasodilatation  reflex tachycardia) Pain / anxiety Hypoxemia (PE / COPD) Cardiac conditions  decreased cardiac output (CHF / MI) Medications (B2 agonists) Drugs (crack / ephedrine) Hyperthyroidism Clinical Conditions Associated with Persistent Sinus Tachycardia

30. Rx – Sinus Tachycardia • Sinus tachycardia is almost always a physiologic response to a given stimulus or disease state • In most situations, do not treat sinus tachycardia, treat the underlying process

31. Focal Atrial Tachycardia

32. Causes – Atrial Tachycardia • Onset is often precipitated by increased sympathetic stimulation • Specific examples: • Digoxin toxicity (especially if AV block noted) • Theophylline (beta-agonist) • EtOH • Myocardial ischemia • Hypoxia

33. Rx – Atrial Tachycardia • Rhythm often spontaneously resolves with normalization of sympathetic tone • If rhythm recurs repeatedly, consider Rx: • Step #1 – beta-blockers (BB) • Step #2 – amiodarone (not if dig toxic) • Step #3 – radio-frequency ablation is curative Kowey PR. Arch Int Med. 1998; 158: 325

34. Atrial Flutter with 2:1 AV block

35. Background - Atrial Flutter • Underlying mechanism – large “macro re-entrant circuit” in the atrium, typically moves counter-clockwise • Atrial rate range: 250-350 bpm • Ventricular response depends on the degree of AV block: • 2:1 block  ventricular rate = 150 bpm • 3:1 block  100 bpm • 4:1 block  75 bpm

36. Causes – Atrial Flutter • Most commonly occurs in male patients with dilated or distended atria with elevated left atrial pressure • Clinical scenarios: • Systolic CHF with low EF • Mitral regurgitation (MR)

37. Rx – Atrial Flutter • Unstable pt (i.e. low BP / CP / AMS): • Synchronized cardioversion as per ACLS • 50J  100J  200J  300J  360J • Stable pt: • Rate control - just like atrial fibrillation (AFib) • Elective cardioversion - just like AFib • Anti-coagulation – just like AFib

38. Atrioventricular Nodal Re-entrant Tachycardia (AVNRT) or AVRT

39. AVNRT or AVRT

40. Rx – AVNRT / AVRT • Unstable: • Synchronized cardioversion start @ 50J (avoid if EF < 40%) • Stable: • Step #1 – attempt to terminate rhythm with vagal maneuvers (carotid massage / Valsalva) • Step #2 – adenosine 6mg IVP  12mg 2min later  18mg 2min later • Step #3 – AV nodal blocking agents (BB / CCB > digoxin) • Step #4 – amiodarone 150mg IV over 10min  1mg/min x 6hrs  0.5mg/min x 18hrs (max dose 2.2g/24hrs) • Step #5 – in pts with bypass tracts not tolerating the medications, consider radio-frequency ablation ACLS 2000 / Wang YS, et al. JACC. 1991; 18:1711

41. Wolf-Parkinson-White (WPW) Syndrome

42. Take Home Messages - WPW • Syndrome features: • Short PR • Broad irregular QRS complexes due to Delta waves • Ventricular rates up to 300 bpm • Conduction along the accessory pathway: • Orthodromic – conduction to ventricles over normal AV node-His-Purkinje path • Antidromic – conduction to ventricles via accessory path • Medical Rx: • 1st choice – procainamide 20mg/min IV (max 17mg/kg) • Drugs to avoid – AV nodal blocking agents!!! • Radio-frequency ablation curative > 95% cases ACLS 2000 / Krahn AD. Ann Intern Med. 1992; 116: 456

43. So What Is Actually Meant By Supraventricular Tachycardia? • Arrhythmias of supraventricular origin using a re-entrant mechanism with abrupt onset & termination • AVNRT (60%) • AVRT (30%) • Atrial tachycardia (10%)

44. Ventricular Tachycardia (VT)

45. Brugada EKG Criteria for VT • AV dissociation • R-S interval > 100 ms • No RS morphology in pre-cordial leads Dr. Brugada (Cardiology) @ Noon Conference – The Methodist Hospital 9/00

46. Classification - VT • Duration: • Sustained VT (> 30 seconds or hemodynamic compromise) • non-Sustained VT (< 30 seconds) • Risk factor for sudden death among pts with heart dz • QRS morphology: • Monomorphic (common in pts with CAD) • Polymorphic (usually associated with a prolonged QT) ACP - MKSAP 12. Cardiovascular Medicine: 24

47. Rx – VT • Hemodynamically Unstable: • Unsynchronized cardioversion as per ACLS protocol for VF / pulseless VT • Unstable (CP / AMS): • Synchronized cardioversion as per ACLS protocol

48. Rx – VT • Stable: • Rx ischemia • Correct electrolytes (K / Mg / Ca) • Consider cardioversion (yes even in stable pts!!) • EF > 40%: • Procainamide / sotalol (class IIa) • amiodarone (class IIb) • EF < 40%: • amiodarone (class IIa)

49. Torsades de Pointes

50. Causes – Torsades de Pointes • Underlying Mechanism – prolongation of the QT interval coupled with R-on-T phenomenon • Medications (Class Ia anti-arrhythmics / TCAs) • Electrolyte abnormalities (Mg / K) • Bradycardia (usually s/p inferior MI)