1. Supra Ventricular Tachycardia (SVT)
Arrhythmias
Supra Ventricular Tachycardia (SVT)
May, 2017
Jai Udassi, MD, FAAP, FACC, FAHA
Associate Professor of Pediatrics
Director Pediatric Cardiac ICU
Division Chief Critical Care (A)
Sidra Medical & Research Center Doha, Qatar

2. Disclosure
No financial or any other conflict

3. Goals/Objectives
Recognize SVT (Garden Variety)
Manage SVT

4. Cardiac Conduction System
Bundle of His

5. Assess pulse Patient with arrhythmia Ensure ABCs Absent Asystole
Assess rhythm
V FIB
Pulse less V Tach
PEA
Absent
Assess pulse
Present
Normal
RBBB,
LBBB,
Low atrial rhythm,
Situs Inversus
WPW syndrome,
Fast
Irregular
Slow
Wide QRS
Narrow QRS
Sinus arrhythmia
Atrial FIB
PAC +/- Block
PVC
Sinus Bradycardia
Sick Sinus
AVN Block
V TACH
Aberrant SVT /Antidromic Tachycardia
V FIB
Sinus Tachycardia
SVT (PAT)
Ectopic Atrial Tachy / Chaotic AT
Atrial flutter/fib
JET

6. 2 years old with fever

7. 6 months old, very irritable for last few hours, HR= 214, stable BP

8. 9 y old, only 3 hours s/p sub AS (membrane) repair
9 y old, only 3 hours s/p sub AS (membrane) repair. HR change from 150 to 200 and not perfusing well

9. 3 years old after Fontan surgery

10. Supra Ventricular tachycardia- SVTs
Re-entry (garden variety)
A= AVRT-orthodromic
(ORT)
B= AVNRT
Automatic
E= JET
F= AT (EAT, Flutter, Fib)
PJRT-junctional to atrial septum
Mahaim fibers-atrial free wall to RV his purkinje system

11. Practical approach Continuous monitoring with good 12 lead EKG
What is the clinical context
History of previous cardiac surgery or acute post op
Classic SVT (garden variety);
Previously healthy
Babies feel irritable or uneasy
Older kids can describe a sensation of a fast heart rate, palpitations, or chest tightness
Fast HR with ‘P’ wave not clear, though 1:1 conduction
Narrow QRS complex (can be wide, if antidromic conduction or bundle branch block, rate dependent)
Most of the time BP is intact

12. SVT / PAT
The tachycardia collectively referred to as supraventricular tachycardia (SVT) or paroxysmal atrial tachycardia (PAT)
Represent the most common tachycardia in pediatric patients.
Abrupt onset and termination, normal QRS complexes, and usually an absence of clearly discernible P waves or flutter waves.

13. SVT
Most frequent age presentation: 1st 3 months of life, 2nd peaks 8-10 years and in adolescence
Rapid, regular, usually narrow QRS rhythm, originating above the ventricles
1st 9 months of life: average heart rate is 270 beats per minute
Older children: average heart rate is 210 beats per minute ( )

14. SVT - Treatment
Goal: identify unstable patients, differentiate from sinus tachycardia, and terminate the rhythm
Vagal maneuvers in stable patients, (ice bag with water and Straw)
Adenosine, need to have IV access readily available, as close to heart as possible
Stops conduction through AV node
Helps to define p waves if unsure of etiology
0.1 mg/kg (max 6 mg), repeat 0.2 mg/kg ( max 12 mg) in line closest to central circulation
Need continuous ECG and BP monitoring
Synchronized cardioversion
Amiodarone, Procainamide if above unsuccessful

17. SVT - Treatment
Need post conversion EKG – identify those with WPW syndrome
( 25 % patients with SVT )
Observation (admission) and Cardiology consult, will also need an echo – identify structural problems
Medications (started by Cardiologist)
Digoxin and beta blockers as first line
Flecainide, sotalol, amiodarone
Radiofrequency catheter ablation (EP Study)
Frontline treatment
Very effective

18. Other SVT’s
Atrial flutter, Atrial fib, ectopic atrial tachycardia, junctional tachycardia
Adenosine does not terminate these rhythms, originate above AV node
Treatments: Amiodarone or cardioversion

19. Administering Adenosine
Patient
3 way stopcock
Adenosine
10 mL flush

20. Adenosine Administration

21. Summary Patients with garden variety SVT usually are stable
Take your time to recognize/diagnosis properly, mostly with narrow QRS, some SVT can present with wide QRS
Always put patient on continuous monitor, be ready to protect airway
If stable try Vagal maneuvers
Put Defibrillation pads on before giving Adenosine
For Adenosine put PIV close to heart, flush well with 5 to 10 ml of saline
If electrical cardioversion is done, make sure sedate the patient