Leonard Steinberg, MD Timothy Knilans, MD The Heart Center Children’s Hospital Medical Center...
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Transcript of Leonard Steinberg, MD Timothy Knilans, MD The Heart Center Children’s Hospital Medical Center...
Leonard Steinberg, MDTimothy Knilans, MD
The Heart CenterChildren’s Hospital Medical Center
Cincinnati, OH
The diagnosis and management of supraventricular tachycardia in
infantsPart I: Establishing a diagnosis
Overview
General information
Categorizing tachycardia
Diagnosis
Therapy (part II)
General information
Occurs in 1 in 250 to 1000 children50% of cases occur in infantsmost present in first 3 months
Low recurrence rate in infantsAP mediated tachycardia recurrences
uncommon by 1 year
some infants have no recurrences at least 30% of infants with an accessory
pathway are non-inducible at 1 year no known predictive factors for recurrence
automatic atrial tachycardias less likely to resolve
Low death rateparticularly if structurally normal heart
Possible presentations
Incidental findingLethargyCongestive heart failure
hydrops diaphoresis tachypnea poor feeding growth failure
ShockStructural heart disease
Heart disease associated with SVT
Accessory pathways Ebstein’s anomaly tricuspid atresia mitral atresia (hypoplastic left heart syndrome) corrected transposition of the great arteries
(L-TGA)
Automatic atrial tachycardias cardiomyopathy / myocarditis
ANY incessant tachycardia can CAUSE cardiomyopathy
Atrial fibrillation always associated with congenital heart
disease
Associated with VERY poor prognosis
Other diseases associated with SVT
Chaotic (or other automatic) atrial tachycardia
RSV
tachycardia unrelated to ß-agonists or hypoxia
patients with structurally normal hearts do not have recurrences
cocaine (in utero)
Categorizing tachycardia
MechanismLocationFrequency
Loc
atio
n
Mechanism
Re-entrant AutomaticAtrial Atrial flutter
Atrial fibrillationAutomatic atrial tachycardiaChaotic atrial tachycardia
AV Node andHis Bundle
AV node re-entry Junctional tachycardia
Atrium andVentricle
WPWConcealed APPJRTMahaim
Classifying tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
(4) atrial fibrillation
Automatic
(1) automatic atrial tachycardia(2) automatic junctional tachycardia(3) chaotic (multifocal)
atrial tachycardia
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromic
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
Categorizing tachycardia: mechanism
x
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
Categorizing tachycardia: mechanism
Slow
Fast
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical
Categorizing tachycardia: mechanism
Slow
Fast
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
(4) atrial fibrillation
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
(4) atrial fibrillation
Automatic
(1) automatic atrial tachycardia
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
(4) atrial fibrillation
Automatic
(1) automatic atrial tachycardia(2) automatic junctional tachycardia
Categorizing tachycardia: mechanism
Re-entrant
(1) reentrant atrial tachycardia (atrial flutter)
(2) AV reentry a. WPW
orthodromicantidromic“two pathway”
b. concealed accessory pathway c. PJRT d. Mahaim
(3) AV node reentry a. typical b. atypical
(4) atrial fibrillation
Automatic
(1) automatic atrial tachycardia(2) automatic junctional tachycardia(3) chaotic (multifocal)
atrial tachycardia
Classifying tachycardia: location
Atrium automatic atrial tachycardia reentrant atrial tachycardia chaotic atrial tachycardia atrial fibrillation
AVN and His bundle AV node reentry tachycardia automatic junctional
tachycardia
Atrium and ventricle accessory pathway tachycardia concealed WPW PJRT Mahaim
Classifying tachycardia: frequency
Common: AV reentry
Less common: atrial
Uncommon: AV node reentry
Rare: other
Frequencyaccessory pathway SVT
Concealed
WPW
PJ RT
Frequencyatrial tachycardias
Atrial reentry
Automatic atrial
Frequencyrare tachycardias
AV node re-entry:frequency uncertain
Frequencyrare tachycardias
Atrial fibrillation
Chaotic atrial
Automatic junctional tachycardia
Mahaim
Differential diagnosisECG analysis
Rate
Atrial activity
AV relationship
Rhythm perturbations
QRS morphology
ECG analysis: rate
200
250
150
300
500
600A
tria
l R
ate
Automatictachycardias
Atrial reentry
PJRT
AVNRT
AVRT
ECG analysis: rate
200
250
150
300
500
600A
tria
l R
ate
Automatictachycardias
Atrial reentry
PJRT
AVNRT
AVRT
Constant rate Variable rate
PJRT
ECG analysis: atrial activity
Where on the ECG shorter diastolic interval compare QRS high frequency activity in T waves look for 2:1 conduction
Where in the atrium (p wave axis) inferior: must be primary atrial
tachycardia superior axis indicates pathology check V1 & V2 when tachycardia looks
like sinus rhythm variable: chaotic atrial tachycardia
ECG analysis: AV relationship
More A’s than V’s
AV reentry •
AV node reentry •Junctional tachycardia •
Primary atrial tachycardia •
More V’s than A’s
•AV reentry•Primary atrial tachycardia
•AV node reentry
•Junctional tachycardia. Wide complex is ventricular until proven otherwise
Excluded
Unlikely
Probably
ECG analysis: the RP interval
Useful in distinguishing AV reentry from AV node reentry tachycardias
70 msec traditionally associated with AVNRT
> 70 msec accessory pathway
> PR interval PJRT or atypical AVNRT
ECG analysisrhythm perturbations
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
Sinus P PAC
ECG analysisrhythm perturbations
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
aVF
V1
Right Atrium
ECG analysisrhythm perturbations
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
P wave No P wave
ECG analysisrhythm perturbations
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
P wave No P wave
ECG analysisrhythm perturbations
Tachycardia onsetBundle branch blockTerminationVagal maneuversAdenosine response
ECG analysisrhythm perturbations
Considerations when terminating SVT
obtain rhythm recording
save vagal maneuvers for known diagnosis
adenosine response accessory pathway
watch for adenosine side effects
ECG analysisrhythm perturbations
ECG analysisQRS morphology
Narrow complex (normally conducted QRS) cannot be antidromic tachycardia
Wide complex any narrow complex tachycardia with aberrant
conduction (more frequently LBBB in infants) any narrow QRS tachycardia mechanism with an
antegrade bystander AP antidromic AV reentrant tachycardia (including Mahaim tachycardia-rare)
* VENTRICULAR TACHYCARDIA* ventricular complexes and aberrantly conducted
supraventricular complexes may have “narrow QRS” appearance
Diagnosisnoninvasive modalities
Holter and event monitors occasionally helpful in establishing
diagnosis evaluate therapeutic effect
Echocardiography incessant tachycardia diminished function structural heart disease prior to EP study
in utero tachycardia
Diagnosisminimally invasive modalities
Atrial electrogram
esophageal lead or atrial pacing wires
identify atrial activity evaluate antegrade conduction over an
accessory pathway effectiveness of therapy
pace terminate re-entrant arrhythmias
The EP study
Rarely requiredUsually performed in association with need
for definitive therapy
Indications refractoriness to multiple medical regimens hemodynamic compromise or poor function concurrent need for hemodynamic
catheterization impending loss of catheter access
ASD closurePalliation for complex congenital heart disease
Summary
Accurate diagnosis as a prelude to therapy
Classify
ECG
Other diagnostic modalities
Structural heart disease