The document discusses various pediatric arrhythmias including tachycardias and bradycardias. It provides details on normal heart rates at different ages and describes common supraventricular tachycardias like AV nodal reentrant tachycardia, accessory pathway mediated tachycardias. It also discusses idiopathic ventricular tachycardia and management strategies for different arrhythmias including medication and ablation. Congenital complete heart block is described along with its association with maternal autoimmune conditions.

1. Pediatric Arrhythmia 台大醫院小兒部 邱舜南醫師

2. Newborn 1 week to 3 months 3 months to 2 years 2 years to 10 years 10 years to adult 100-180 100-220 80-170 70-110 55-90 80-160 80-200 70-120 60-90 50-90 Up to 220 Up to 220 Up to 200 Up to 200 Up to 200 Age Resting (awake) Resting (sleeping) Exercise, fever Heart Rate (beats per min) Normal heart rates for infants and children

3. Pediatric Arrhythmia Tachycardia: PSVT VT Bradycardia: Sinus bradycardia AV block

4. Paroxysmal supraventricular tachycardia

5. Supraventricular tachycardia in pediatric patients * HR 215-350 (mean 280) in infants * 98% narrow QRS * Atrial fibrillation 0.4% 1-4% in infants with preexcitation

6. Josephson Wu D Gillette Ko Wu M Naheed (adult) (adult) (Ped) (Ped) (Ped) (Fetal) AVNRT 51 72 24 13 18 - AVRT 34 13 33 73 72 73 Atrial 15 15 42 14 10 27

7. PSVT in children AVRT AVNRT EAT

8. AVRT in Pediatric Patients * Peak age: young infants 5- 8 yr >13 yr * The younger the onset age, the less the recurrences ~ JACC 16(5):1215-20, 1990

9. AVRT * Manifest (delta wave) 0.06-0.3% general population 0.3-1% congenital heart disease * Concealed 57% for all AP (68% for left AP, 42% for right AP) * Ebstein’s anomaly * l –TGA * ? Heterotaxy syndrome

10. WPW WPW ~ A Population Study of the Natural History of Wolff-Parkinson-White Syndrome in Olmsted Count, Minnesota, 1953-1989(Circulation 1993;87:866-873

11. Preexcitation and Wolff-Parkinson-White Syndrome Bundle branch block with short PR interval in healthy young people prone to paroxysmal tachycardia Wolff L, Parkinson J, White PD. Am Heart J 1930:5:686-692.

12. Preexcitation Syndrome Pre-excitation : an anomalous atrioventricular connection capable of antegrade and usually retrograde conduction. WPW syndrome : patients with both pre-excitation in the surface ECG and symptoms caused by arrhythmias, either regular (circus movement tachycardias) or irregular (atrial fibrillation).

13. Tachycardia in WPW syndrome

14. Clinical manifestation of AVRT in infants & children Risk of Af (Vf): 1.5/1000 patient years, increases in the 2 nd decade 42 cases with cardiac arrest due to WPW, median 10 yr, 1day to 21yrs, mortality 36%, sequalae 33% Risk factor: shortest RR at Af < 250 (220) ms, multiple AC ,

15. AV Nodal Reentrant Tachycardia (AVNRT) Dual AV nodal pathway (AH jump for 50 ms), but may be innocent Rare in children younger than 5 years of age Slow-fast AVNRT

18. Atrial Tachycardia (AT) Warm-up & cool-down in ectopic AT, but reentry in postop intra-atrial reentry tachycardia May associated variable AV conduction or BBB A propensity to secondary cardiomyopathy

19. Management of SVT Vagal maneuver Adenosine Rapid flush from IV cath nearest to heart 0.1 then 0.2mg/kg (max. 6 then 12mg) Verapamil : 0.1 mg/kg, contraindicate in infant, use careful in young child, not use in manifest WPW Digoxin, ß-blocker, Procainamide, Amiodarone Cardioversion if hemodaynamically unstable

21. Treatment strategies of SVT in pediatric patients: medical or ablation * Natural history- prefer medication at age <6y/o * Complications- Potential lesion growth, coronary injury, AV block, vessel injury, … * Ablation efficacy and safety

22. Initial Success of RFCA of SVT in Children Without CHD AVRT 91% (2816/3110) AVNRT 96% (885/920) 98% (60/61) 100% (15/15) PRCAR NTUH-P Favor able factors left lateral AP(95%) experience (> 20 cases) Unfavorable factors Right free wall AP(86%) Septal AP (87%) decreased BW

23. Probability of supraventricular tachycardia recurrence in pediatric patients Wu et al. Cardiology. 85(5):284-9, 1994. 90 patients with initial SVT episode before 15 yr (f/u 2-228; median, 215 months). Mobidity: CHF 14 (16%), CVA 1. SVT recurrence were associated with an older age at initial SVT episodes (p < 0.001). Even though, about 40% of the patients whose initial attacks occurred during infancy had recurrences 5 years later.

24. Complications of RFCA of SVT in Children Without CHD AV block 0.68% (25) 1% (1) Perforation 0.66% (10) 0 (0) brachial palsy 0.27% (10) 2% (2, transient) emboli 0.22% (8) 0 (0) pneumothorax 0.19% (7) 0 (0) death 0.11% (4) 0 (0) Risk factors : BW <15 kg, left free AP, experience AV block risk factors : anteroseptal AP, AVNRT, BW < 15 kg PRCAR NTUH-P 3.2% (118) 3 (3)

25. RFCA of SVT in Children Without CHD Recurrences AVRT 23 % 12 % AVNRT 29 % 7 % Unfavorable factors right free wall septal pathway PRCAR NTUH-P

26. Result of PSVT ≦ 5y/o Final success rate of RFCA for all diagnoses was 94%. Total recurrence rate was 13%. Atrial tachycardia in postoperative CHD was associated with the lowest success rate (57%) and highest recurrence rate (25%). RFCA of SVT in those less than 6 years-old has comparable success and recurrence rate. But for AVNRT or paraHisian accessory pathway, conservative treatment is still suggested Int J Cardiol 72 (2000) 221–227

27. Ventricular Tachycardia

28. Etiology Relative rare in pediatric patients. Congenital- congenital long QT syndrome, Brugada syndrome?, Arrhythmogenic RV dysplasia Idiopathic VT Acquired Myocarditis, HCM, DCM hypoxemia, acidosis, e- imbalance, toxin CHD postoperatively as TOF s/p Myocardial tumor

29. Congenital Long QT Syndromes Romano-Ward (1963) & Jerwell-Lange-Nelson (1957) Ion channel defects

30. ß-blocker therapy Left cardiac sympathetic denervation ICD implantation

31. Idiopathic VT Idiopathic RV VT vs. Idiopathic LV VT The younger onset age, more spontaneous resolution Syncope, heart failure (cardiomyopathy) 15% Medication, RFCA ~ JACC 33(7): 2062-72, 1999

32. 86 VT patients in our institution (M/F 49/37) Infant Child(1-10yr) Adolescent p value VT spon. resolution 4/5(80%) 0/10(0%) 1/20(5%) <0.05(I. vs C.) <0.05(I. vs A.) Ablation 0/0(0%) 4/10(40%) 16/20(80%) 0.11(I. vs C.) <0.05(I vs A.) Recur After Ablation 1/4(25%) 3/16(18%) 0.79 Idiopathic LV RV P-value Initial success 17/18(94%) 2/3(67%) 0.271 Recurrence 3/17(17%) 2/2(100%) 0.058

33. Management of VT Amiodarone : 5 mg/kg over 20-60 min, max 15mg/kg Prolong QT, hypotension Procainamide : 15 mg/kg over 30-60 min. Prolong QT, induce polymorphic VT, AV block, myocardial suppression Lidocaine : 1mg/kg then 20-50ug/kg/min Most effective in VT caused by myocardial ischemia Vasopressin : 0.4-1U/kg/dose then 0.005-0.1 U/kg/hr No more recommend in child DC cardioversion : 0.5~1 J/kg then 2 J/kg.

36. Bradyarrhythmia Sinus bradycardia Sinus node dysfunction (SSS) rare in children except CHD postoperatively (Senning, TCPC) Hypoxemia, hypothermia, acidosis, e- imbalance, toxin, … AV block

37. Atrioventricular block Acquired: surgery (VSD, LVOTO, L-TGA), myocarditis Congenital: transplacental autoimmune injury l -TGA

38. CAVB associated with myocarditis Return of AV conduction in 67% of young myocarditis with advanced AV block patients. The average time of recovery is 3.3 ± 2.8 days. persistent AV block > 1 week indicates the need for permanent cardiac pacing. ~ Pediatr Cardiol 24:495–497, 2003

39. Congenital AV block 1/15,000 –20,000 live birth Maternal SLE with SSA/anti-Ro, SSB/anti-La (+) May associated with LQTS Usually irreversible and need a pacemaker Pacemaker free survival rate

40. Congenital AV block Epicardial VVI® pacemaker Transvenous VDD pacemaker

41. F/U of congenital CAVB Lead problems- fracture SCD due to prolonged QT DCM

42. Bradyarrhythmias – treatment Atropine 0.02 mg/kg IV (IO or ET) Minimum: 0.1 mg Maximum: 0.5 mg in children; 1 mg in adolescent. May repeat once. Epinephrine Isoprotenolol Transcutaneous pacing

44. Thanks for your attention!