1. Pediatric emergency case conference Presented by R3 李智晃

2. General and triage information  Chart No. :7168xx9  Date of birth: 85/08/08  Gender: male  Body weight: 35kg  Time on arrival: 2006/06/19 PM 16:15  Vital signs: 36.3/200/20, BP not measurable  家屬主訴心悸，外院表示 tachycardia ，建議轉診

3. Chief complaint and present illness  C.C: palpitation since AM 10:00  Present illness Chest tightness and SOB was noted Activity: good No vomiting No cough, no fever  Past history: Similar episode last year

4. Physical examination  HEENT: no active lesion  Heart: tachycardia without murmur  Chest: clear breathing sound  Abdomen: sort and flat  Extremities: freely movable  Immediate EKG monitoring: tachycardia up to 200/min

5. Was the patient ill?  PAT Appearance- conscious clear, good activity Breathing- mild tachypnea Circulation- tachycardia, BP not measurable, strong peripheral pulsation, no cold or mottled skin

6. EKG on arrival

7. Initial management  Adenosine 3.5 mg IV stat  On 3-way lock  CBC/DC, CK-MB, Troponin-I, Ca, Na, K,BUN  Admission to ward  On EKG monitor

8. ECG after treatment

9. Final diagnosis  Paroxysmal supraventricular tachycardia  WPW syndrome

10. PSVT - Pathophysiology

11. Introduction and epidemiology  Prevalence around 1/250-1/25000  Most common form AVRT (including WPW syndrome) AVNRT

12. AV reentrant tachycardia (including WPW syndrome)  presence of an extranodal accessory pathway connecting the atrium and ventricle  Antegrade vs. retrograde  Antidromic vs. orthodromic

13. Antegrade versus retrograde Pre-excitation caused by antegrade conduction by accessory pathway. So-called Wolff-Parkinson-White (WPW) pattern.

14. Orthodromic tachycardia WPW

15. Antidromic tachycardia WPW

16. 12 lead ECG in antidromic AVRT WPW

17. PSVT - management

18. PALS algorithm for SVT

19. Hemodynamic assessment - PAT  Appearance- pallor, or decreased level of consciousness  Breathing- tachypnea, subcostal retraction, use of accessory muscle  Circulation- hypotension, heart failure, signs of shock,.  Signs in infants- irritability, tachypnea, and poor feeding.

20. Hemodynamic unstable  Cardioversion Direct current cardioversion at 0.5 to 2.0 J/kg, synchronized Use pediatric electrode paddles (surface area 21 cm2) Adequate sedation before the procedure

21. Diagnostic evaluation  History incompatible with sinus tachycardia  P waves absent or abnormal  Heart rate does not vary with activity  The presence of abrupt changes in heart rate  Rate usually >220 beats/min in infants and >180 beats/min in children

22. Vagal maneuvers  ECG should be continuously monitored  Infant and younger children Application of a bag filled with ice and cold water over the face for 15 to 30 seconds Rectal stimulation using a thermometer  Older children bearing down (Valsalva maneuver) for 15 to 20 seconds  Carotid massage and orbital pressure should not be performed in children

23. Antiarrhythmic drugs  Used while failure to convert the rhythm with vagal maneuvers  Drugs of choice Adenosine Verapamil Procainamide Amiodarone Digoxin was not suggested, especially under the suspicion of WPW syndrome

24. Adenosine  Mechanism Interact with A1 receptor of cardiac muscle Delay of AV nodal conduction Block the re-entry cycle  Dosage 0.1mg/kg, doubled if no response in 2 minutes 0.05mg/kg, increase by 0.05mg/kg every 2 minutes to total maximal dose of 0.25 to 0.35mg/kg or total 12mg is given

25. Verapamil  Mechanism to slow AV nodal conduction  Dosage intravenous infusion in a dose of 0.1 to 0.3 mg/kg with a maximum dose of 10 mg  Contraindications Infant less than one year old Children with heart failure Children suspected with WPW syndrome Children with wide QRS complex

26. Procainamide  No IV form in CGMH  Mechanism inhibiting phase 0 (sodium-dependent) depolarization and slows atrial conduction  Dosage Loading dose  Infant- 7 to 10 mg/kg is given over 30 to 45 minutes  Oldr children- 15 mg/kg continuous infusion of procainamide starting at 40 to 50 mcg/kg per minute

27. Amiodarone  Used for SVT refractory to other anti-arrhythmic agents  Can be used safely in patient with WPW syndrome  Mechanism prolongs the refractory period of the AV node and the duration of the action potential and the refractory period of both atrial and ventricular myocardium  Dosage bolus infusion of 5 mg/kg over 20 to 60 minutes, repeated up to a total of 20 mg/kg Continuous infusion of 10 to 15 mg/kg per day.

28. Chronic therapy  ECG after acute episode should be performed to look for evidence of WPW syndrome  Medications Digoxin  Radiofrequency ablation

29. Reference  Up to date. Ver. 14.2 Supraventricular tachycardia in children: AV reentrant tachycardia (including WPW) and AV nodal reentrant tachycardia Management of supraventricular tachycardia in children  Pediatric advanced life support (PALS), 2nd edition