Cardiac Arrhythmia Emergencies

Cardiac Arrhythmia Emergencies

Anthony F. Rossi, MD

Director, Cardiac Critical Care Services

Miami Children’s Hospital

Miami, Fl

Anthony F. Rossi, MD

Director, Cardiac Critical Care Services

Miami Children’s Hospital

Miami, Fl

ECG BasicsECG Basics

Atrial Depolarization

HIS Bundle Depolarization

Ventricular Depolarization

NSRNSR

Arrhythmia Categories

Tachycardias» SVT» Junctional » Ventricular

Bradycardia» SND» HB

Asystolic

Mechanisms of Mechanisms of TachyarrythmiasTachyarrythmias

Reentry Abnormal automaticity After deploarizations

Reentrant Arrhythmias

Paroxysmal» Acute start» Acute termination» No warm up

Can be started/terminated with premature beat

Reentrant LoopReentrant Loop

PAC Causing ReentryPAC Causing Reentry

Abnormal AutomaticityAbnormal Automaticity

warms up / cools downswarms up / cools downs not initiated by extrastimulusnot initiated by extrastimulus not terminated by extra stimulusnot terminated by extra stimulus no overdrive suppressionno overdrive suppression

warms up / cools downswarms up / cools downs not initiated by extrastimulusnot initiated by extrastimulus not terminated by extra stimulusnot terminated by extra stimulus no overdrive suppressionno overdrive suppression

Abnormal AutomaticityAbnormal Automaticity

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-40-40thresholdpotential

thresholdpotential00

11 22

33

44

TP1TP1

TP2TP2

00

-40-40-60-60 aa

bbresting potentialresting potential

00 33

44

SVT

Most common treated arrhythmia in children

Almost never life-threatening in otherwise well children

Infancy common presentation age May resolve as child matures

SVT: Presentation

Infants» Poor feeding» Pallor» S+S of CHF

Older Children» Palpitations» Chest pain/discomfort

Orthodromic SVTOrthodromic SVT

ECG Dx of SVT

p r p r

-Short pr-long rp

-”fast-slow”

r p r

AV recip tach AVN reentry PJRT

SVT: Treatment

Adenosine» 50-500 mcg/kg» Rapid IV push» May transiently convert to NSR» Transient SND, PVCs» Systemic Vasodilatation most dangerous side

effect

Overdrive pacing (TEP or use atrial wires) Cardioversion

Malignant Wide Complex TachycardiaMalignant Wide Complex Tachycardia after Adenosine after Adenosine Administration to a Pediatric Postoperative Patient with Administration to a Pediatric Postoperative Patient with

Congenital Heart DiseaseCongenital Heart DiseaseKipel et al. Pediatr Cardiol. 1995 Jan-Feb;16(1):36-7.Kipel et al. Pediatr Cardiol. 1995 Jan-Feb;16(1):36-7.

SVT: Treatment

Synchronized Cardioversion Begin antiarrhythmic agents, then attempt

adenosine/cardioversion at later date Drugs:

» Digoxin (IV in sick babies)» Procainamide» Verapamil (contraindicated in pts < 1 yr)» B-blocker

WPWWPW

Short pr

Delta wave

WPWWPW

WPW

Ebstein’s (9%), L-TGA (1%), HCM (1%)Ebstein’s (9%), L-TGA (1%), HCM (1%) Narrow complex tachycardia most Narrow complex tachycardia most

commoncommon Digoxin is contraindicated (accelerated Digoxin is contraindicated (accelerated

ventricular response)ventricular response) B-blocker or amiodaroneB-blocker or amiodarone

Initiation of SVT in WPWInitiation of SVT in WPW

NSR with pre-excitationNSR with pre-excitation PACPAC Narrow Complex SVTNarrow Complex SVT

Antidromic SVTAntidromic SVT

WPW with A FibWPW with A Fib

Afib WPWAfib WPW

NSR?18 yo s/p Mustard operation presents “feeling tired”

Adenosine 6 mg iv push given

Diagnosis is atrial flutter (intra-atrial reentry)

-treatment options include

-cardioversion

-overdrive pacing (TEP or transvenous)

-medical cardioversion (class lll agent ibutilide)

SVT ?

NB infant with HR of 240 BPM

Adenosine 200 mcg/kg IV push

Atrial FlutterAtrial Flutter

Atrial FlutterAtrial Flutter

Most frequently seen in infants or older pts after atrial surgery (Mustard/Senning, Fontan)

Treatment depends on duration and degree of hemodynamic compromise

Is there evidence of SND?

Intraatrial Reentry (flutter)Intraatrial Reentry (flutter)

A Flutter with 2:1 A Flutter with 2:1 ConductionConduction

Atrial FlutterAtrial Flutter

Rate control (ventricular response)» B-blocker» Ca channel blocker» Digoxin

Conversion» Cardioversion» Pharmacologic (acute, sub-acute, chronic)

Atrial FlutterAtrial Flutter

SNDSND» Need the ability to pace since SNRT may Need the ability to pace since SNRT may

be very prolonged after cardioversion be very prolonged after cardioversion (overdrive suppression of SN)(overdrive suppression of SN)

» Epicardial wiresEpicardial wires» Transvenous wiresTransvenous wires» TE wireTE wire

Atrial FlutterAtrial Flutter

Death» Prolonged pause after conversion» Rapid ventricular response in pt with

structural heart disease» Anesthesia induction (loss of sympathetic

tone leads to hypotension and coronary perfusion problem)

Atrial FibrillationAtrial Fibrillation

PJRTP

R

8 yo girl transferred to the ER with Dx of DCM, severe LV dysfunction

PJRTPJRT

Atypical or “fast-slow” type SVT Incessant nature May cause tachycardia induced

cardiomyopathy Resistant to drug therapy Terminates with adenosine, but only

transiently

PVC

QRS is prematureQRS is premature Morphology of QRS is different from Morphology of QRS is different from

baseline (did you see the po ECG?)baseline (did you see the po ECG?) QRS is prolongedQRS is prolonged ST abnormalitiesST abnormalities No PAC notedNo PAC noted

BigeminyBigeminy

V TachV Tach

V TachV Tach

V Tach

Accurate Dx is essential prior to Accurate Dx is essential prior to beginning Rxbeginning Rx» SVT with aberrant conductionSVT with aberrant conduction» Assume V TachAssume V Tach» 12 lead ECG if Stable12 lead ECG if Stable

– AV dissociation? Fusion bts? Rate < 250?AV dissociation? Fusion bts? Rate < 250?

MayMay be life threatening be life threatening

V Tach: Treatment

Clinical condition Underlying disease state

» Structurally normal heart» CHD» Myocarditis» DCM

Hemodynamically stable (sustained)» Procainamide» Amiodarone» Lidocaine

V Tach: Treatment         Am J Cardiol. 1996 Jul 1;78(1):82-3

Comparison of procainamide and lidocaine in terminating sustained monomorphic ventricular tachycardia.

Gorgels AP, van den Dool A, Hofs A, Mulleneers R, Smeets JL, Vos MA, Wellens HJ.

- Lidocaine converted 20% V tach-Procainamide converted 80% V tach

V Tach: Long QT

CongenitalCongenital» Intense emotions, Intense emotions,

vigorous activity, vigorous activity, awakeningawakening

» Auto Dom: Romano-Auto Dom: Romano-WardWard

» Auto Rec: Jervell and Auto Rec: Jervell and Lange-NielsenLange-Nielsen

» B-blocker, pacing, B-blocker, pacing, AICDAICD

AcquiredAcquired» Pause dependent, Pause dependent,

short-long-short QRS short-long-short QRS sequencesequence

» Antiarrhythmics, Antiarrhythmics, phenothiazines and phenothiazines and tricyclics, low K, low tricyclics, low K, low MgMg

» DC causative agent, DC causative agent, IV Mg, K, temp IV Mg, K, temp pacing, isoprelpacing, isoprel

V Tach: Treatment

Hemodynamically unstable» Cardioversion!!!

Torsade de Pointes

Long QtLong Qt

V Tach: Long QT

Acquired (drug induced)Acquired (drug induced)» QuinidineQuinidine» HypokalemiaHypokalemia

CongenitalCongenital

Arrhythmias After CHS

Occur in > 25% of patients (CHOP) <10% MCH (JET 0.9%, CHB requiring pacemaker

0.15%) Risk Factors

» “At Risk” myocardium (long standing hypertrophy, volume load, etc.)

» Myocardial ischemia, cardioplegia» Ventriculotomy» Electrolyte Disturbances

Majority of clinically significant arrhythmias occur with first 48 hours of surgery –Marino BS, et al Circulation 2000

–Hoffman TM, et al Ped Cardiol 2002–Fishberger SB, et al Cardiol Young 2007

Acute Arrhythmias Acute Arrhythmias Associated with CH Associated with CH

SurgerySurgery

V Tach (early or late)V Tach (early or late)» Older pts (re-do po TOF, history of ventriculotomy)Older pts (re-do po TOF, history of ventriculotomy)» Sicker heartsSicker hearts» Coronary perfusion problems (ischemia)Coronary perfusion problems (ischemia)

JET (early ONLY)JET (early ONLY)» NB and infantsNB and infants» VSD closure (any VSD including TOF, TGA/VSD)VSD closure (any VSD including TOF, TGA/VSD)» FontanFontan

Acute Arrhythmias Acute Arrhythmias Associated with CH Associated with CH

SurgerySurgery Atrial Flutter/Fib (usually late)Atrial Flutter/Fib (usually late)

» History of Mustard/Senning, FontanHistory of Mustard/Senning, Fontan» History of ASD repair (usually older pt)History of ASD repair (usually older pt)» Fontan operationFontan operation

SND (late or early)SND (late or early)» All above plus:All above plus:» AVC AVC » BiGlenn BiGlenn

CHB (early or late)CHB (early or late)» VSD closure (any type)VSD closure (any type)» L-TGA (any intra-cardiac surgery)L-TGA (any intra-cardiac surgery)

IV AmiodaroneIV Amiodarone

2-5 mg/kg IV over 30 mins» hypotension: volume, Ca++, slow infusion» Bradycardia early and LATE! Dangerous w/o ability

to pace (cause SND) repeat in 1 hour if arrhythmia control is not

satisfactory AV pace if ventricular rate allows add procainamide if poor response cool to 35o C

2-5 mg/kg IV over 30 mins» hypotension: volume, Ca++, slow infusion» Bradycardia early and LATE! Dangerous w/o ability

to pace (cause SND) repeat in 1 hour if arrhythmia control is not

satisfactory AV pace if ventricular rate allows add procainamide if poor response cool to 35o C

CHB

Congenital» 1/20,000 births

Acquired» Post surgery

– Usually related to VSD closure

» CHD: L-TGA» myocarditis

Bradycardias

SNDSND Second degree heart blockSecond degree heart block

» Mobitz 1Mobitz 1» Mobitz 2Mobitz 2

Complete heart blockComplete heart block

Sinus BradycardiaSinus Bradycardia

Most common bradyarrhythmia in the ICUMost common bradyarrhythmia in the ICU Usually related to hypoxia and airway Usually related to hypoxia and airway

problemsproblems» Treat underlying causeTreat underlying cause» AtropineAtropine» Epinephrine Epinephrine » Isuprel Isuprel

Seen in pts with increased ICPSeen in pts with increased ICP» Treat underlying causeTreat underlying cause

SNDSND Most commonly seen in pts with a previous history ofMost commonly seen in pts with a previous history of

» Mustard/Senning OperationMustard/Senning Operation» Fontan operationFontan operation» BiGlennBiGlenn

Occasionally noted acutely following surgeryOccasionally noted acutely following surgery Often associated with atrial arrhythmias (flutter:tachy-brady Often associated with atrial arrhythmias (flutter:tachy-brady

syndrome)syndrome) Important historically because drug therapy may exacerbateImportant historically because drug therapy may exacerbate Pauses of > 3 sec often noted after termination of tachycardiaPauses of > 3 sec often noted after termination of tachycardia

Mobitz 1 (WenckebachMobitz 1 (Wenckebach)

Increasing PR interval leading to blockIncreasing PR interval leading to block Shortest PR after blocked beatShortest PR after blocked beat Block occurs in AV node (above HIS)Block occurs in AV node (above HIS) May be related to drugs which block the AV May be related to drugs which block the AV

node, or increased vagal tonenode, or increased vagal tone Usually benignUsually benign Rarely requires treatmentRarely requires treatment Occurs in pts with normal conduction systemOccurs in pts with normal conduction system

Mobitz II

No PR prolongation Block occurs below AVN (distal to HIS) Pathologic

» Requires close observation» May progress» May require treatment

CHBCHB

CHBCHB

Treatment» Depends on symptoms» Acute treatment includes

– Atropine– Epinephrine– Isuprel– Pacing

» Post surgical CHB requires permanent pacing» Transient HB in PO period may progress to CHB

later in life

Trifascicular BlockTrifascicular Block

PR=0.221. Ist degree AVB

2. RBBB

3. LAHB

Electrical AlternansElectrical Alternans

Large Pericardial EffusionLarge Pericardial Effusion