Approach to Childhood Arrhythmias

1. Approach to Childhood Arrhythmias • Tachyarrhythmias • Classification • Diagnostic approach • Immediate treatment strategies • Long term management of tachyarrhythmias • Bradyarrhythmias

2. Non invasive diagnosis of tachycardia Classification of tachycardia • conventional SVT / VT • electrophysiological re-entry / automatic • appearance normal QRS / wide QRS • age infancy / childhood • behaviour paroxysmal / incessant • structural normal / post-op • significance Bland / nasty • substrate e.g. accessory connection • Mechanism e.g. orthodromic AV re-entry

3. Typical responses! Panic is an unnecessary and inappropriate response because most childhood arrhythmias are associated with stable hemodynamics

4. Arrhythmia Management: Basic Rule • Diagnosis before treatment • A variety of incorrect practices in management of arrhythmias result from a failure to respect this simple rule Unless it is an emergency resist the urge to treat the arrhythmia before being sure what it is!

5. Diagnostic Approach for Tachyarrhythmias Traditional Classification Broad QRS Often unstable hemodynamics Ventricular /supraventricular Narrow QRS Usually stable hemodynamics Supraventricular

6. Diagnosis of tachycardia Classification of tachycardia

7. Diagnosis of tachycardia essential information • history - age of onset, symptoms, etc • ECG in tachycardia • ECG in sinus rhythm • ECG with adenosine administration

8. Arrhythmias – clinical features • Irregular heart beat • Inappropriate heart rate for the situation • Unexplained CHF • Diseases associated with arrhythmias • Syncope/palpitations • Family history

9. Arrhythmias: The First Step • Connect the child to an ECG machine • Get a 12 lead ECG • If the child is uncooperative, at least get the limb leads

10. The Monitor Can Mislead • Single non-standard lead • P waves are not often clearly seen • Interpretation of QRS morphology • Regular vs. Irregular rhythm • Difficult to document response to intervention

11. Non invasive diagnosis of tachycardia ECG analysis - normal QRS • are the QRS complexes regular? • are P waves seen? • what is the AV or VA relationship? • where is the P wave in the RR interval?

12. Irregular Atrial fibrillation Multifocal or chaotic atrial tachycardia Flutter with varying conduction Regular Sinus tachycardia Atrial Flutter AV nodal re-entrant tachycardia Tachycardias based on bypass tracts Narrow QRS Tachycardia • Ectopic atrial tachycardia • Junctional ectopic tachycardia

14. Irregular Narrow QRS Tachycardia

15. Fast AF in patient with ASD

16. Irregular Narrow QRS Tachycardia A Flutter with varying conduction Ectopic atrial tachycardia MAT

17. P wave morphology I II III

18. 12 Lead ECG: P-QRS Relationship A-V dissociation: JET

19. Sinus Tachycardia

20. Sinus Tachycardia: A Cause Can Almost Always be Found • Anxiety • Fever • Hypovolemia • Hyperthyroidism • Bronchodilators

21. Sinus Tachycardia: In the ICU • “Light” sedation • Inotropes and chronotropes • Low output • Fever (rectal temp) • Hypovolemia

22. Sinus Tachycardia • Rates can be as high as 240/min • Subtle variations in rate • Treating cause brings down the rate • When in doubt: 12 lead ECG • If doubts persist: adenosine

23. Narrow QRS Tachycardia: P Waves are not always Seen…..

24. Diagnosis of tachycardia • Recording response to adenosine • Ultra short acting • Blocks conduction across the AV node • Terminates tachyarrhythmias where AV node is a part of the circuit • Temporarily slows heart rates if circuit above AV node

25. Administering Adenosine Saline bolus, fast push 10 cm extn. Reliable proximal IV line Adenosine 50-200 mcg/kg, fast push

27. Sudden termination No effect Slow and unmask AVNRT AVRT Sinus tachy, Junctional ectopic tachycardia Flutter, ectopic atrial tachy Stable Narrow QRS tachycardia Adenosine 140 mcg/kg bolus

28. Response to Adenosine Tachycardia Sinus AV nodal re-entrant tachycardia: Sudden termination with adenosine

29. Atrial Atrial Surface Response to Adenosine Tachyarrhythmia after Senning + Rastelli (LTGA, VSD, PS) Abrupt restoration to Sinus Rhythm after adenosine

30. Response to Adenosine Narrow QRS tachycardia @ 200/min Unmasking of atrial activity (Flutter waves)

31. Alternatives to Adenosine • Ice bag on face; effects similar to adenosine • Older children and teens: • Carotid sinus massage, supine valsalva • Verapamil 0.1 mg / kg slow (only for narrow QRS tachycardias • Cardioversion: Synchronized DC shock - 0.5 – 1 J/kg. First line for unstable narrow QRS tachycardia

32. Response to DC Shock Responders: all re-entrant arrhythmias A Flutter, AVRT, AVNRT, reentrant VT Non-responders: all tachycardias based on automatic foci JET, EAT, Sinus tachycardia, MAT

33. After the Event: ECG in Sinus Rhythm

34. Sinus Tachycardia Flutter Ectopic atrial Tachycardia Cardioversion Beta Blockade Digoxin Amiodarone Treat the Cause Digoxin, Betablockade Rarely Amiodarone Failure of the tachycardia to terminate after adenosine

35. Tachycardiomyopathy • Certain incessant tachycardia in children can present clinically with heart failure and LV dysfunction like “myocarditis or DCM” • Permanent Junctional Re-entrant tachycardia: RF ablation • Ectopic atrial tachycardia: Antiarrhythmic medications / RF ablation

36. Non invasive diagnosis of tachycardia ECG analysis - wide QRS • what is the QRS morphology in sinus rhythm? • is the QRS pattern LBBB, RBBB, pre-excited, other? • are the QRS complexes regular? • are P waves seen? • what is the AV / VA relationship?

41. TORSADES DE POINTES

42. Wide QRS tachycardia Unstable Stable • If 1:1 P-QRS relation, try adenosine • If AV dissociation, IV Lignocaine 1 mg/kg or IV amiodarone 5 mg/kg • If no response, DC shock DC shock CPR

43. VT • Synchronized DC shock 0.5-2 J/kg • VF • Unsynchronized DC shock 2-4 J/kg Unstable Wide QRS Tacharrhythmia

44. ECG After the Event…….. Long QT syndrome