Download Pediatric Dysrhythmias Board Review

Pediatric Dysrhythmias
Board Review
February 11, 2008
Brad Rodrigue, M.D.
Pediatric dysrhythmias
Treatment not required
Treatment is required
Sinus arrhythmia
Supraventricular tachycardia
Wandering atrial pacemaker
Isolated premature atrial
contractions
Isolated premature
ventricular contractions
First degree AV block
Ventricular tachycardia
Third degree AV block with
symptoms
Reproduced from Zitelli’s Atlas of Pediatric physical diagnosis, 2007, pg 140.
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?
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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
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Sinus arrhythmia
Wandering atrial pacemaker
Atrial pacemaker shifts from sinus node to
another atrial site
 Normal variant, irregular rhythm
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Isolated PAC’s
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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)
Isolated PAC’s
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
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PVC’s
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If unifocal, disappear with exercise, and
associated with structurally and functionally
normal heart, then considered benign, no
therapy needed
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
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First degree AV block
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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
First degree AV block
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Diseases that can be associated with first
degree AV block: rheumatic fever, rubella,
mumps, hypothermia, cardiomyopathy,
electrolyte disturbances
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
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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
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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
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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 peaks @ 8-10 and in
adolescense
 Rapid, regular, usually narrow QRS
rhythm, originating above the ventricles
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SVT
Figure 5-42 Supraventricular tachycardia. Note a normal QRS complex
tachycardia at a rate of 214 beats/minute without visible P waves.
SVT
Paroxysmal, sudden onset & offset
 Rates of SVT vary with age
 Overall average rate for all ages: 235 bpm
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– 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
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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
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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
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– 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
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SVT - Treatment
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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
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Observation and expectant management
Medications
– Digoxin and beta blockers as first line
– Flecainide, sotalol, amiodarone
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
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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.
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
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V-Tach
Treatment: IV lidocaine, procainamide,
amiodarone
 If critically ill: synchronized cardioversion
 Long term: meds, ablation, or defibrillator
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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
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V-fib
Brugada syndrome – inherited arrhythmia,
autosomal dominant person goes into vfib, faints, dies suddenly
 Treatment: defibrillator, careful screening
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That’s all!