1. Pediatric Dysrhythmias Board Review
February 11, 2008
Brad Rodrigue, M.D.

2. Pediatric dysrhythmias
Treatment not required
Treatment is required
Sinus arrhythmia
Supraventricular tachycardia
Wandering atrial pacemaker
Isolated premature atrial contractions
Isolated premature ventricular contractions
Ventricular tachycardia
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. Wandering atrial pacemaker
Atrial pacemaker shifts from sinus node to another atrial site
Normal variant, irregular rhythm

7. Isolated PAC’s Premature atrial contractions
Benign in absence of underlying heart dz
Common in newborn period
Early p wave, sometimes with different morphology than a sinus p wave
Can be either:
Not conducted to ventricle, apparent pause
Conducted to ventricle with aberrant or widened QRS complex ( careful not to mix up with PVC’s)

8. Isolated PAC’s

9. Premature Ventricular Contractions (PVC’s)
Not very commonly seen in children
Incidence of 0.3 to 2.2 %
Early, wide QRS complexes
T waves in opposite direction of QRS
Unifocal PVC’s are most encountered type
Bigeminy, sinus beat followed by PVC, repeating as a pattern, also frequently seen

10. PVC’s
If unifocal, disappear with exercise, and associated with structurally and functionally normal heart, then considered benign, no therapy needed

11. PVC’s evaluation 12 lead EKG, Echocardiogram Perhaps Holter monitoring
Brief exercise in office to see if ectopy suppressed or more frequent
Multifocal or paired PVC’s more worrisome
Medications usually not needed
Advise patients to avoid caffeine and other stimulants

12. 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
msec in newborns is normal
msec in young children and adults
Generally does not cause bradycardia since AV conduction remains intact

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

14. 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

15. 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

16. 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

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

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

19. 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( )
P waves difficult to define, but 1:1 with QRS
Important to differentiate from sinus tach

20. 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

21. SVT - Treatment
Goal: identify unstable patients, differentiate from sinus tachycardia, and terminate the rhythm
Vagal maneuvers in stable patients
Adenosine if IV access readily available
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

22. SVT - Treatment
Need post conversion EKG – 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

23. Other SVT’s
A flutter, A fib, ectopic atrial tachycardia, junctional tachycardias
Not commonly seen in pediatric patients
Adenosine does not terminate these rhythms, originate above AV node
Treatments: procainamide, amiodarone, cardioversion, or ablation

24. 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.

25. 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

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

27. 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

28. V-fib
Brugada syndrome – inherited arrhythmia, autosomal dominant person goes into v-fib, faints, dies suddenly
Treatment: defibrillator, careful screening

29. That’s all!