supraventricular tachycardia in infancy and childhood terrence chun, md pediatric electrophysiology...
TRANSCRIPT
Supraventricular Supraventricular TachycardiaTachycardia
in Infancy and Childhoodin Infancy and Childhood
Terrence Chun, MDTerrence Chun, MD
Pediatric Electrophysiology and PacingPediatric Electrophysiology and Pacing
Cardiac electrical anatomyCardiac electrical anatomy
SVT - OverviewSVT - Overview
Rapid rhythm that involves or is Rapid rhythm that involves or is driven by structures in the upper driven by structures in the upper heartheart
Incidence up to 1:250 childrenIncidence up to 1:250 children Generally well-tolerated, even fast Generally well-tolerated, even fast
ratesrates Risk of life-threatening arrhythmias Risk of life-threatening arrhythmias
is uncommonis uncommon
Narrow vs. Wide QRSNarrow vs. Wide QRS
Not all narrow QRS complex Not all narrow QRS complex tachycardia is supraventricular tachycardia is supraventricular tachycardiatachycardia
Not all wide QRS complex Not all wide QRS complex tachycardia is ventricular tachycardia is ventricular tachycardiatachycardia
SVT Mechanisms - SVT Mechanisms - OverviewOverview
Reentrant rhythmsReentrant rhythms Automatic rhythmsAutomatic rhythms
SVT mechanisms –SVT mechanisms –
Automatic RhythmsAutomatic Rhythms
Originate from a particular focusOriginate from a particular focus ““Warm-up” and “cool-down” behaviorWarm-up” and “cool-down” behavior Respond to drugs and maneuvers Respond to drugs and maneuvers
that affect myocardial automaticitythat affect myocardial automaticity May be suppressed by faster ratesMay be suppressed by faster rates Usually do not respond to Usually do not respond to
cardioversion (typically pause, then cardioversion (typically pause, then restart)restart)
SVT mechanisms –SVT mechanisms –
Automatic RhythmsAutomatic Rhythms
Left atrial focusLeft atrial focus 2:1 AVN conduction2:1 AVN conduction
SVT mechanisms –SVT mechanisms –
Reentrant rhythmsReentrant rhythms
Requires a “circuit” of tissue to Requires a “circuit” of tissue to create repetitive activationcreate repetitive activation
Must have appropriate conditions to Must have appropriate conditions to perpetuate reentrant rhythmperpetuate reentrant rhythm
Usually abrupt onset and Usually abrupt onset and terminationtermination
Regular, with little variation in rateRegular, with little variation in rate Often will respond to cardioversionOften will respond to cardioversion
SVT mechanisms –SVT mechanisms –
Reentrant rhythmsReentrant rhythms
Diagnostic methodsDiagnostic methods
12-lead electrocardiogram ! ! !12-lead electrocardiogram ! ! ! Post-op atrial/ventricular pacing Post-op atrial/ventricular pacing
wireswires Esophageal pacing leadsEsophageal pacing leads Adenosine can be diagnosticAdenosine can be diagnostic Invasive electrophysiology studyInvasive electrophysiology study
Diagnostic methodsDiagnostic methods
AlwaysAlways AlwaysAlways AlwaysAlways record a record a rhythm striprhythm strip
during any intervention during any intervention (adenosine, cardioversion, (adenosine, cardioversion, Valsalva, etc.)Valsalva, etc.)
Diagnostic methodsDiagnostic methods
Record a rhythm stripRecord a rhythm strip
ECG clues to diagnosisECG clues to diagnosis
Wide vs. narrow complexWide vs. narrow complex Regular vs. irregularRegular vs. irregular Abrupt vs. gradualAbrupt vs. gradual P wave relationship to QRSP wave relationship to QRS
Parade of RhythmsParade of Rhythms
Automatic ArrhythmiasAutomatic Arrhythmias
Automatic rhythms –Automatic rhythms –
Sinus TachycardiaSinus Tachycardia
Sinus node – fish-shaped structure Sinus node – fish-shaped structure with “head” at SVC-RA junction and with “head” at SVC-RA junction and “tail” extending along RA wall“tail” extending along RA wall
S-tach usually due to increased S-tach usually due to increased sympathetic discharge, fever, sympathetic discharge, fever, anemia, hypovolemia, anemia, hypovolemia, hyperthyroidism, etc.hyperthyroidism, etc.
Inappropriate sinus tachycardia - rareInappropriate sinus tachycardia - rare
Automatic rhythms – Automatic rhythms –
Sinus TachycardiaSinus Tachycardia
DxDx Rate greater than normal range, but Rate greater than normal range, but
usually less than 200usually less than 200 P wave axis normal (0 ~ +90P wave axis normal (0 ~ +90°°)) PR interval normalPR interval normal
TxTx Treat the causeTreat the cause
Automatic rhythms – Automatic rhythms –
Automatic Atrial Automatic Atrial TachycardiaTachycardia
Originates from a focus in either the Originates from a focus in either the right or left atrium, or atrial septumright or left atrium, or atrial septum
Commonly from atrial appendages, Commonly from atrial appendages, crista terminalis, pulmonary veinscrista terminalis, pulmonary veins
Can also be due to central lines, etc.Can also be due to central lines, etc. Also called “ectopic atrial tachycardia”Also called “ectopic atrial tachycardia”
although any automatic rhythm other although any automatic rhythm other than sinus rhythm is technically “ectopic”than sinus rhythm is technically “ectopic”
Automatic rhythms – Automatic rhythms –
Automatic Atrial Automatic Atrial TachycardiaTachycardia
DxDx Speeds-up and slows-down, rates varySpeeds-up and slows-down, rates vary P wave axis abnormalP wave axis abnormal PR interval may be abnormal (it is a PR interval may be abnormal (it is a
function of distance from focus to AVN)function of distance from focus to AVN) May see 2May see 2° AV block (e.g. Wenckebach ° AV block (e.g. Wenckebach
or 2:1 at higher atrial rates)or 2:1 at higher atrial rates) Adenosine Adenosine P waves “march through” P waves “march through”
despite AV blockdespite AV block
Automatic rhythms – Automatic rhythms –
Automatic Atrial Automatic Atrial TachycardiaTachycardia
Automatic rhythms – Automatic rhythms –
Automatic Atrial Automatic Atrial TachycardiaTachycardia
TxTx Remove source (check CXR and pull Remove source (check CXR and pull
back PICC)back PICC) Beta-blockersBeta-blockers
Esmolol infusion in ICU settingEsmolol infusion in ICU setting propranolol, atenololpropranolol, atenolol
Amiodarone, othersAmiodarone, others Catheter ablationCatheter ablation
Automatic rhythms – Automatic rhythms –
Junctional TachycardiaJunctional Tachycardia
Originates from around the AV Originates from around the AV junctionjunction
Also called “JET” (Junctional Ectopic Also called “JET” (Junctional Ectopic Tachycardia), because it sounds coolTachycardia), because it sounds cool
Rate 170-200+Rate 170-200+ Most commonly seen post-Most commonly seen post-
operatively, usually self-limitedoperatively, usually self-limited Congenital forms, more persistentCongenital forms, more persistent
Automatic rhythms – Automatic rhythms –
Junctional TachycardiaJunctional Tachycardia
DxDx AV dissynchronyAV dissynchrony
Sinus P wave at different rate than narrow Sinus P wave at different rate than narrow QRSQRS
Atrial wire ECG (in post-op with pacing Atrial wire ECG (in post-op with pacing wires)wires)
““Cannon a-waves” on CVP monitorCannon a-waves” on CVP monitor Retrograde P waves (abnormal Pw axis)Retrograde P waves (abnormal Pw axis)
May be on top, before, or after QRSMay be on top, before, or after QRS
Automatic rhythms – Automatic rhythms –
Junctional TachycardiaJunctional Tachycardia
Cannon a-wavesCannon a-waves
Automatic rhythms – Automatic rhythms –
Junctional TachycardiaJunctional Tachycardia
TxTx Reduce catecholaminesReduce catecholamines
Decrease inotropic dripsDecrease inotropic drips Pain control and sedationPain control and sedation
Cooling/hypothermiaCooling/hypothermia Drugs (amiodarone)Drugs (amiodarone) ECMOECMO Catheter ablation(?)Catheter ablation(?)
Parade of RhythmsParade of Rhythms
Reentrant ArrhythmiasReentrant Arrhythmias
Reentrant rhythms – Reentrant rhythms –
Pathway Mediated Pathway Mediated TachycardiaTachycardia
Bypass tract of conductive tissue Bypass tract of conductive tissue connects atrium to ventricleconnects atrium to ventricle
Most common mechanism of SVT in Most common mechanism of SVT in childrenchildren
Rate 180-240Rate 180-240 May be “manifest” (e.g. WPW) or May be “manifest” (e.g. WPW) or
concealed (no preexcitation)concealed (no preexcitation) Pathway can be anywhere on mitral or Pathway can be anywhere on mitral or
tricuspid annuli, usually left-sidedtricuspid annuli, usually left-sided
Reentrant rhythms – Reentrant rhythms –
Pathway Mediated Pathway Mediated TachycardiaTachycardia
Orthodromic reciprocating tachycardiaOrthodromic reciprocating tachycardia ““Runs correctly” with normal conductionRuns correctly” with normal conduction Down AV node (narrow QRS)Down AV node (narrow QRS) Up accessory pathway (retrograde)Up accessory pathway (retrograde) Retrograde P waves may be visible after QRSRetrograde P waves may be visible after QRS
Antidromic reciprocating tachycardiaAntidromic reciprocating tachycardia ““Runs against” normal conductionRuns against” normal conduction Down accessory pathway (wide QRS)Down accessory pathway (wide QRS) Up AV node (retrograde)Up AV node (retrograde) Less commonLess common
Reentrant rhythms – Reentrant rhythms –
Pathway Mediated Pathway Mediated TachycardiaTachycardia
DxDx ElectrocardiogramElectrocardiogram Rhythm strips of start and stop of SVTRhythm strips of start and stop of SVT
Reentrant rhythms – Reentrant rhythms –
Pathway Mediated Pathway Mediated TachycardiaTachycardia
TxTx Valsalva maneuvers, Ice to faceValsalva maneuvers, Ice to face Adenosine (technique matters!)Adenosine (technique matters!) Antiarrhythmic drugsAntiarrhythmic drugs
Beta blockers (watch blood glucose in Beta blockers (watch blood glucose in infants!)infants!)
Digoxin (limited value; digitalization only in Digoxin (limited value; digitalization only in difficult situations)difficult situations)
Others (Verapamil, Flecainide, Sotolol, etc.)Others (Verapamil, Flecainide, Sotolol, etc.) Catheter ablationCatheter ablation
Reentrant rhythms – Reentrant rhythms –
Wolff-Parkinson-White Wolff-Parkinson-White SyndromeSyndrome
Electrocardiogram findingsElectrocardiogram findings Short PR intervalShort PR interval Wide QRS complexWide QRS complex Delta waveDelta wave
Reentrant rhythms – Reentrant rhythms –
Wolff-Parkinson-White Wolff-Parkinson-White SyndromeSyndrome
Reentrant rhythms – Reentrant rhythms –
Wolff-Parkinson-White Wolff-Parkinson-White SyndromeSyndrome
Clinical symptomsClinical symptoms PalpitationsPalpitations SVTSVT
Note narrow QRS and lack of delta wave!Note narrow QRS and lack of delta wave!
Reentrant rhythms – Reentrant rhythms –
Wolff-Parkinson-White Wolff-Parkinson-White SyndromeSyndrome
Sudden death(!)Sudden death(!) Atrial fibrillationAtrial fibrillation Rapid conduction over bypass tractRapid conduction over bypass tract Ventricular fibrillationVentricular fibrillation Risk 0.1-0.6% per yearRisk 0.1-0.6% per year
Reentrant rhythms – Reentrant rhythms –
Wolff-Parkinson-White Wolff-Parkinson-White SyndromeSyndrome
TxTx Tachycardia controlTachycardia control
RecognitionRecognition ±±Drugs (patient/family choice)Drugs (patient/family choice) Digoxin generally contraindicatedDigoxin generally contraindicated
Risk stratificationRisk stratification HolterHolter Exercise testingExercise testing Invasive electrophysiology testingInvasive electrophysiology testing
Catheter ablationCatheter ablation
Reentrant rhythms – Reentrant rhythms –
AV Node Reentry AV Node Reentry TachycardiaTachycardia
More common in teens and adultsMore common in teens and adults Tachycardia circuit contained within Tachycardia circuit contained within
atrioventricular nodeatrioventricular node Activates atria at the “top” of the Activates atria at the “top” of the
circuit, ventricles at “bottom” of circuit, ventricles at “bottom” of circuit, nearly simultaneouslycircuit, nearly simultaneously
Rate 200-250Rate 200-250 Usually cannot see retrograde P Usually cannot see retrograde P
waveswaves
Reentrant rhythms – Reentrant rhythms –
AV Node Reentry AV Node Reentry TachycardiaTachycardia
Reentrant rhythms – Reentrant rhythms –
AV Node Reentry AV Node Reentry TachycardiaTachycardia
TxTx AdenosineAdenosine CardioversionCardioversion ±±PharmacotherapyPharmacotherapy
Beta blockersBeta blockers DigoxinDigoxin OthersOthers
Catheter ablationCatheter ablation
Reentrant rhythms – Reentrant rhythms –
Atrial FlutterAtrial Flutter
““Flutter” circuit Flutter” circuit around anatomic around anatomic structures in structures in atriumatrium Eustachian valveEustachian valve Crista terminalisCrista terminalis Fossa ovalisFossa ovalis Surgical incisionsSurgical incisions
Reentrant rhythms – Reentrant rhythms –
Atrial FlutterAtrial Flutter
Atrial rate ~300 (higher in Atrial rate ~300 (higher in neonates)neonates)
Ventricular rate depends on AV Ventricular rate depends on AV node conductionnode conduction 1:1 1:1 300/min 300/min 2:1 2:1 150/min 150/min 3:1 3:1 100/min 100/min May be 3:1 then 2:1 then…May be 3:1 then 2:1 then…
Reentrant rhythms – Reentrant rhythms –
Atrial FlutterAtrial Flutter
Sawtooth “flutter” waves (may or Sawtooth “flutter” waves (may or may not be helpful)may not be helpful)
Reentrant rhythms – Reentrant rhythms –
Atrial FlutterAtrial Flutter
DxDx ElectrocardiogramElectrocardiogram Adenosine blocks AV node; flutter Adenosine blocks AV node; flutter
waves continuewaves continue TxTx
Rate control – digoxin, beta blockers, Rate control – digoxin, beta blockers, etc.etc.
Overdrive pacingOverdrive pacing DC cardioversionDC cardioversion Catheter ablationCatheter ablation
Threatening RhythmsThreatening Rhythms
Atrial fibrillation in high-risk WPWAtrial fibrillation in high-risk WPW Danger of ventricular fibrillationDanger of ventricular fibrillation
Persistent prolonged SVTPersistent prolonged SVT Tachycardia induced cardiomyopathy Tachycardia induced cardiomyopathy
(reversible)(reversible) SVT in compromised cardiac statusSVT in compromised cardiac status
Syncope or cardiovascular collapseSyncope or cardiovascular collapse
Treatment PearlsTreatment Pearls
AdenosineAdenosine
0.1-0.4 mg/kg/dose0.1-0.4 mg/kg/dose Very short half-life (seconds)Very short half-life (seconds) Central administration can be Central administration can be
helpful, but not necessaryhelpful, but not necessary RapidRapid saline bolus (5-10 ml) saline bolus (5-10 ml)
essentialessential Stopcock on venous access is Stopcock on venous access is
helpfulhelpful
DC CardioversionDC Cardioversion
DoseDose Cardioversion 0.25-1 J/kgCardioversion 0.25-1 J/kg Defibrillation 1-2 J/kgDefibrillation 1-2 J/kg
Synchronized (avoids making worse)Synchronized (avoids making worse) Paddles – front+apexPaddles – front+apex PatchesPatches
Front+apexFront+apex Front+backFront+back
Catheter AblationCatheter Ablation
Multiple cathetersMultiple catheters Size limitationsSize limitations
Ideally > 15 kg, but can be done in Ideally > 15 kg, but can be done in infants if necessaryinfants if necessary
Can be curativeCan be curative ~95% success rate in children~95% success rate in children
Record a Rhythm Strip!Record a Rhythm Strip!
Especially during interventionsEspecially during interventions Most SVT in infants and children is Most SVT in infants and children is
hemodynamically well-toleratedhemodynamically well-tolerated Proper diagnosis can guide Proper diagnosis can guide
appropriate therapyappropriate therapy RA/LA/RL/LL limb leads give 6 RA/LA/RL/LL limb leads give 6
electrograms (I, II, III, aVL, aVR, electrograms (I, II, III, aVL, aVR, aVF)aVF)