The causes listed are all potential causes for syncope in children. The most common causes are neurocardiogenic syncope, breath-holding spells, and seizures. Other important considerations include cardiac causes like long QT syndrome, hypertrophic cardiomyopathy, and aortic stenosis.

1. Pediatric Dysrhythmias
Dr.B.BALAGOBI

2. Pediatric dysrhythmias
Treatment not required Treatment is required
Sinus arrhythmia Supraventricular tachycardia
Wandering atrial pacemaker
Isolated premature atrial
contractions
Isolated premature Ventricular tachycardia
ventricular contractions
First degree AV block Third degree AV block with
symptoms
Reproduced from Zitelli’s Atlas of Pediatric physical diagnosis, 2007, pg 140.

3. Pediatric dysrhythmias
 Vital to be aware of arrhythmias that occur
in otherwise healthy children
 Management is individualized
 Does child have history of heart disease?
 Are symptoms present?

4. Sinus arrhythmia
 Most common irregularity of heart rhythm
seen in children
 Normal variant
 Reflects healthy interaction between
autonomic respiratory and cardiac control
activity in CNS
 Heart rate increases during inspiration and
decreases during respiration

5. Sinus arrhythmia

6. First degree AV block
 Commonly seen (up to 6% normal neonates)
 PR interval is greater than upper limits of normal
for a given age
 PR interval is age and rate dependent
 70-170 msec in newborns is normal
 80-220 msec in young children and adults
 Generally does not cause bradycardia since AV
conduction remains intact

7. First degree AV block
 Diseases that can be associated with first
degree AV block: rheumatic fever, rubella,
mumps, hypothermia, cardiomyopathy,
electrolyte disturbances

8. Third degree AV block
 AKA complete heart block
 Most common cause of abnormal
bradycardia in infants and children
 Complete disassociation between P
waves and QRS complexes

9. Third degree AV block
 Can be congenital – in this case it is
strongly associated with maternal SLE
 Mom of an infant should be worked up
 Most common structural heart defect
associated is corrected transposition of
great vessels

10. Third degree AV block
 May be asymptomatic – follow clinically
 Slower the heart rate, and wide QRS
escape rhythms place into high risk group
 May need implantable pacemaker:
significant bradycardias, syncope,
exercise intolerance, ventricular
dysrhythmias, or ventricular arrhythmias,
structural disease
 Possible acute treatment: isoproterenol

11. Supraventricular tachycardia
 Most common abnormal tachycardia seen
in pediatric practice
 Most common arrhythmia requiring
treatment in pediatric population
 Most frequent age presentation: 1 st 3
months of life, 2nd peaks @ 8-10 and in
adolescense
 Rapid, regular, usually narrow QRS
rhythm, originating above the ventricles

12. SVT
Figure 5-42 Supraventricular tachycardia. Note a normal QRS complex
tachycardia at a rate of 214 beats/minute without visible P waves.

13. SVT
 Paroxysmal, sudden onset & offset
 Rates of SVT vary with age
 Overall average rate for all ages: 235 bpm
– 1st 9 months of life: avg rate is 270 bpm
– Older children: avg rate is 210 bpm( 180-250)
 P waves difficult to define, but 1:1 with
QRS
 Important to differentiate from sinus tach

14. SVT
 Older kids can describe a sensation of a
fast heart rate, palpitations, or chest
tightness
 Hemodynamic compromise in newborns
and those with structural heart disease
 Those with typical symptoms would
benefit from cardiac consultation

15. SVT - Treatment
 Goal: identify unstable patients, differentiate from
sinus tachycardia, and terminate the rhythm
 Vagal maneuvers in stable patients(successful in 80%)
– Carotid sinus massage
– Ice pack on face
 Adenosine if IV access readily available(Rx of choice)
– Stop 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
 Transesophageal atrial pacing can also be performed

16. SVT - Treatment
 Need post conversion ECG – identify those with
WPW syndrome ( 25 % pts with SVT)
 Will also need an echo – identify structural problems
 Radiofrequency catheter ablation
– Frontline treatment
– Very effective
– Cutoff points usually are 5 y.o. and 15 kg, unless severe
SVT
 Observation and expectant management
 Medications
– Digoxin and beta blockers as first line
– Flecainide, sotalol, amiodarone

17. SVT - WPW
Figure 5-43 Wolff-Parkinson-White syndrome. Note the characteristic findings of a short P-R
interval, slurred upstroke of QRS (delta wave), and prolongation of the QRS interval.

18. Ventricular tachycardia
 Sustained V-tach is uncommon, needs
workup
 Regular wide complex tachycardia
 Atrioventricular dissociation
 Life threatening arryhthmia
 Often presents in those who have had
open heart surgical repair, or those with
cardiomyopathies, myocarditis, or tumors

19. V-Tach
 Treatment: IV lidocaine, procainamide,
amiodarone
 If critically ill: synchronized cardioversion
 Long term: meds, ablation, or defibrillator

20. Ventricular fibrillation
 Seen in children with EKG abnormalities
such as long QT syndrome, or Brugada
syndrome
 Cardiomyopathies, structural heart
disease causing ventricular dysfunction
 Treatment: immediate defibrillation, CPR

21.  Sinus tachycardia can be associated with :
 a) Fever
 b) Hemorrhage
 c) Exercise
 d) Breath holding
 e) Anxiety
 f)anaemia

22.  A 6-week-old infant is brought to the well-baby
visit. nurse discovers a rapid heart rate. The
ECG shows a regular, narrow QRS
tachycardia with a rate of 260 beats/minute.
Appropriate therapy for this problem could
include all of the following
 a) Intravenous administration of adenosine
 b) Placing an examination glove filled with ice
over the infant's forehead
 c) Intravenous administration of verapamil
 d) Application of gentle abdominal pressure to
mimic a Valsalva maneuver
 e)Cardioversion

23. T/F concerning congenital
complete heart bock
 a) It can be associated with maternal
systemic lupus erythematosus.
 b) It can be associated with complex
congenital heart disease.
 c) It is typically treated with a cardiac
pacemaker.
 d) The ECG typically demonstrates a
prolonged PR interval.
 E)associated with TGA

24. Causes for syncope in children
are?
 a) Severe aortic stenosis
 b) Long QT syndrome
 c) Seizure disorder
 d) Fluid depletion
 e) Hypoglycemia
 f)Breath-holding spells
 g) Hypertrophic cardiomyopathy
 h) Neurocardiogenic syncope