TachydysrrhythmTachydysrrhythmiasias

Lisa Campfens MD, FRCPC, Lisa Campfens MD, FRCPC, FACEPFACEP

Generation of Generation of DysrrhythmiasDysrrhythmiasTwo fundamental causesTwo fundamental causes

Disturbances of automaticityDisturbances of automaticity Disturbances of conductionDisturbances of conduction

AV blockAV block ReentryReentry

PresentationPresentation

Multiple symptoms:Multiple symptoms:FatigueFatigue Chest painChest pain

Dyspnea DizzinessDyspnea Dizziness

PresyncopePresyncopePalpitationsPalpitations

Patients can be symptomatic even Patients can be symptomatic even with single premature beats or non-with single premature beats or non-sustained atrial arrhythmiassustained atrial arrhythmias

ComplicationsComplications

SVTs common but persistentSVTs common but persistent Rarely life-threatening but present Rarely life-threatening but present

sig problems in patient managementsig problems in patient management A fib/A flutter: Stroke 2°to A fib/A flutter: Stroke 2°to

embolizationembolization Persistence of tachycardia :Persistence of tachycardia :

Dilated cardiomyopathyDilated cardiomyopathy CHFCHF

ReferralReferral

All patients with wide complex All patients with wide complex tachycardia of unknown origintachycardia of unknown origin

Resistant/intolerant to Resistant/intolerant to pharmacological therapypharmacological therapy

WPW SyndromeWPW Syndrome

Classification ofClassification ofAntidysrrhythmic DrugsAntidysrrhythmic Drugs

Vaughan Williams classificationVaughan Williams classification Class I: Na channel blockersClass I: Na channel blockers Class II: B blockersClass II: B blockers Class III: K channel blockersClass III: K channel blockers Class IV: Ca channel blockersClass IV: Ca channel blockers Other: adenosine, digoxin, and Other: adenosine, digoxin, and

ibutilideibutilide

Class I: Na Channel Class I: Na Channel BlockersBlockers

Class IAClass IA Quinidine, Quinidine, ProcainamideProcainamide

Class IB Class IB Lidocaine, Phenytoin, Lidocaine, Phenytoin, MexilitineMexilitine

Class IC Class IC Flecainide, PropafenoneFlecainide, Propafenone

ProcainamideProcainamide

Therapeutic useTherapeutic use Ventricular tachycardiaVentricular tachycardia SVT with aberrancySVT with aberrancy Pre-excitation SyndromesPre-excitation Syndromes

Class II: Beta Class II: Beta BlockersBlockers

Metoprolol, Atenolol, EsmololMetoprolol, Atenolol, Esmolol

Therapeutic useTherapeutic use Slow ventricular rate (A fib/ A Slow ventricular rate (A fib/ A

flutter)flutter) Terminate SVT caused by an AV Terminate SVT caused by an AV

nodal reentrant circuitnodal reentrant circuit

Class II: Beta Blockers Class II: Beta Blockers (cont’d)(cont’d) Adverse effectsAdverse effects

Heart blockHeart block Heart failureHeart failure AV blockAV block Sinus arrestSinus arrest HypotensionHypotension Bronchospasm Bronchospasm

(asthma/COPD)(asthma/COPD)

Class III: K Channel Class III: K Channel BlockersBlockers

AmiodaroneAmiodarone

Therapeutic useTherapeutic use Life-threatening ventricular Life-threatening ventricular

dysrrhythmiasdysrrhythmias SVT with aberrancySVT with aberrancy Pre-excitation SyndromesPre-excitation Syndromes

.

Class IV: Ca Channel Class IV: Ca Channel BlockersBlockers

Verapamil, DiltiazemVerapamil, Diltiazem

Therapeutic useTherapeutic use Slow ventricular rate (A fib/ A Slow ventricular rate (A fib/ A

flutter)flutter) Terminate SVT caused by an AV Terminate SVT caused by an AV

nodal reentrant circuitnodal reentrant circuit

Other Antidysrhythmic Other Antidysrhythmic DrugsDrugsAdenosineAdenosine

Half-life few secondsHalf-life few seconds Intense but transient AV block thereby Intense but transient AV block thereby

terminating tachycardiaterminating tachycardia Safe in patients with heart diseaseSafe in patients with heart disease Contraindications: asthma/COPDContraindications: asthma/COPD

Therapeutic useTherapeutic use termination of PSVTtermination of PSVT

PSVTsPSVTs

A FibrillationA Fibrillation A FlutterA Flutter AVNRTAVNRT AVRT (ORT)AVRT (ORT)

ReentryReentry

Most common Most common mechanismmechanism

Requires two Requires two separate paths of separate paths of conductionconduction

Requires an area Requires an area of slow conductionof slow conduction

Requires Requires unidirectional unidirectional blockblock

Regular SVT in AdultsRegular SVT in Adults

90% reentrant 90% reentrant 60% AVNRT60% AVNRT 30% AVRT (ORT)30% AVRT (ORT) 10% Atrial tachycardia10% Atrial tachycardia 2 to 5% involve WPW syndrome2 to 5% involve WPW syndrome

AV Nodal Reentrant AV Nodal Reentrant TachycardiaTachycardia

Re-entrant circuit Re-entrant circuit is small and is in is small and is in or closely related or closely related to the AV nodeto the AV node

Slow pathway

Fast pathway

AV Nodal Reentrant AV Nodal Reentrant TachycardiaTachycardia

3o % respond to vagal 3o % respond to vagal maneuvers maneuvers

Very responsive to AVN Very responsive to AVN blocking agents: B blocking agents: B blockers, CA channel blockers, CA channel blockers, adenosine.blockers, adenosine.

Recurrences are the Recurrences are the norm on medical norm on medical therapytherapy

Catheter ablation 95% Catheter ablation 95% successful with 1% successful with 1% major complication ratemajor complication rate

Orthodromic Orthodromic Reciprocating Reciprocating TachycardiaTachycardia

Anterograde over Anterograde over AV node and AV node and retrograde retrograde conduction of an conduction of an accessory pathway.accessory pathway.

Frequently Frequently presents in patients presents in patients with WPW as with WPW as narrow complex narrow complex tachycardiatachycardia

Up accessory pathway

Conduction down AVnode

ORTORT Amenable to AV Amenable to AV

nodal blocking nodal blocking agents in absence of agents in absence of WPW syndrome WPW syndrome (anterograde (anterograde conduction of conduction of pathway)pathway)

Amenable to catheter Amenable to catheter ablation with 95% ablation with 95% success and 1% rate success and 1% rate major complicationmajor complication

Conduction down AVnode

Up accessory pathway

Atrial TachycardiaAtrial Tachycardia

Atrial rate 150-250 bpmAtrial rate 150-250 bpm Does not require AVN or infranodal Does not require AVN or infranodal

conductionconduction P wave morphology different P wave morphology different PR interval PR interval >> 120 ms 120 ms

differentiating from junctional differentiating from junctional tachycardiatachycardia

Atrial TachycardiaAtrial Tachycardia

Left atrial focus- P wave upright Left atrial focus- P wave upright V1/negative in aVL V1/negative in aVL

Right atrial focus-P wave negative Right atrial focus-P wave negative V1/upright in aVL V1/upright in aVL

Adenosine may help with diagnosis Adenosine may help with diagnosis 70-80% will also terminate with 70-80% will also terminate with

Adenosine.Adenosine.

Atrial TachycardiaAtrial Tachycardia

Most are due to Most are due to abn automaticity abn automaticity and have right and have right atrial focusatrial focus

May be reentry in May be reentry in patients with prev patients with prev atriotomy scar, atriotomy scar, such as CABG or such as CABG or congenital repair congenital repair patientspatients

Atrial Tachycardia Atrial Tachycardia TherapyTherapy

AntiarrhythmicsAntiarrhythmics Class 1 : procainamide, quinidine, Class 1 : procainamide, quinidine,

flecainide Patients without structural flecainide Patients without structural heart disease.heart disease.

Class III : sotalol, amiodarone, dofetilideClass III : sotalol, amiodarone, dofetilide

AVN blocking agents for rate control AVN blocking agents for rate control

Catheter ablation effective in 70-80%Catheter ablation effective in 70-80%

Atrial FlutterAtrial Flutter Rate 250 to 350 bpmRate 250 to 350 bpm Rotates counter-Rotates counter-

clockwise around right clockwise around right atrium using a protected atrium using a protected isthmus isthmus

Negative saw-tooth Negative saw-tooth pattern leads II , III, AVF pattern leads II , III, AVF and positive in lead V1and positive in lead V1

Treatment similar to Treatment similar to atrial tachycardia but atrial tachycardia but rate control more rate control more difficultdifficult

Atrial Flutter and Risk of Atrial Flutter and Risk of StrokeStroke

Although risk of stroke historically Although risk of stroke historically thought tothought to

be low, multiple instances of stroke be low, multiple instances of stroke with with

cardioversion lead to similar indication cardioversion lead to similar indication forfor

anticoagulation as AFanticoagulation as AF

42 year old smoker presents to the ED 42 year old smoker presents to the ED with palpitations. BP 100/60. with palpitations. BP 100/60.

A. Emergent cardioversion for A. Emergent cardioversion for polymorphicpolymorphic VTVT

B. IV procainamideB. IV procainamide C. IV lidocaineC. IV lidocaine D. IV diltiazem to obtain rate control.D. IV diltiazem to obtain rate control.

AnswerAnswer

WPW with AF and a rapid WPW with AF and a rapid ventricular response. He is stable, ventricular response. He is stable, thus IV procainamide indicated to thus IV procainamide indicated to slow conduction down the slow conduction down the accessory pathwayaccessory pathway

Diltiazem contraindicatedDiltiazem contraindicated Lidocaine will have no effect, as is Lidocaine will have no effect, as is

not VTnot VT

Epidemiology of AFEpidemiology of AF

Affects 2-4% of populationAffects 2-4% of population Increases to 5-10 % >80 yrsIncreases to 5-10 % >80 yrs 2-fold increased risk of death2-fold increased risk of death 15-25% of all strokes in US 15-25% of all strokes in US

attributed to AFattributed to AF Risk of thromboembolism approx Risk of thromboembolism approx

5%/yr but may be as high as 20% in 5%/yr but may be as high as 20% in high risk groups not anticoagulatedhigh risk groups not anticoagulated

Management of Atrial Management of Atrial FibrillationFibrillation

Symptom relief by rate and rhythm Symptom relief by rate and rhythm controlcontrol

Reduce risk of thromboembolism by Reduce risk of thromboembolism by anticoagulationanticoagulation

Prevent tachycardia-mediated Prevent tachycardia-mediated cardiomyopathycardiomyopathy

Acute Management of AFAcute Management of AF

Focus on rate controlFocus on rate control

DC cardioversion or pharmacologic DC cardioversion or pharmacologic conversion if <48 hrs or following TEE on conversion if <48 hrs or following TEE on Heparin without evidence of left atrial Heparin without evidence of left atrial thrombusthrombus

Following cardioversion anticoagulate for Following cardioversion anticoagulate for 4 wks with goal INR of 2-3 until atrial fx 4 wks with goal INR of 2-3 until atrial fx normalizes**normalizes**

Acute Management of AFAcute Management of AF

50% spontaneously convert <24 50% spontaneously convert <24 hourshours

Digoxin used heavily in past for Digoxin used heavily in past for prevention/ conversion, ineffective prevention/ conversion, ineffective at eitherat either

May be profibrillatory as May be profibrillatory as decreases atrial refractory perioddecreases atrial refractory period

Acute Management of Acute Management of Atrial FibrillationAtrial Fibrillation

Rate control: Ca channel blockers or B Rate control: Ca channel blockers or B blockers in patients with normal LV fxblockers in patients with normal LV fx

Cautious use of Ca channel blockers if Cautious use of Ca channel blockers if depressed LV fx. Associated with depressed LV fx. Associated with increased mortality in long term.increased mortality in long term.

Avoid Beta blockers in acutely Avoid Beta blockers in acutely decompensated CHF patients with AFdecompensated CHF patients with AF

AF and Depressed LV FxAF and Depressed LV Fx

Digoxin and amiodarone may be Digoxin and amiodarone may be effective if LV dysfx and effective if LV dysfx and decompensated CHF to slow decompensated CHF to slow ventricular response.ventricular response.

Digoxin alone rarely effective when Digoxin alone rarely effective when patient sympathetically drivenpatient sympathetically driven

Avoid high dose digoxin with Avoid high dose digoxin with amiodarone as digoxin levels increase amiodarone as digoxin levels increase 2-fold with amiodarone2-fold with amiodarone

Chronic Management of Chronic Management of AFAF

Maintenance of sinus similar with Maintenance of sinus similar with class I and class III drugs-50% class I and class III drugs-50% recurrence at 1 yearrecurrence at 1 year

Recurrence of AF 80% at 1 year Recurrence of AF 80% at 1 year without treatmentwithout treatment

Chronic Management of Chronic Management of AFAF

Recent large trials reveal no benefit of Recent large trials reveal no benefit of rhythm vs rate controlrhythm vs rate control

Trend of increased mortality in rhythm arm Trend of increased mortality in rhythm arm

Patients unable to tolerate AF due to Patients unable to tolerate AF due to symptoms were not enrolled in these symptoms were not enrolled in these studies and are increasingly undergoing studies and are increasingly undergoing ablation , catheter and surgical proceduresablation , catheter and surgical procedures..

Wide Wide ComplexTachycardiasComplexTachycardias

Ventricular TachycardiaVentricular Tachycardia SVT with aberrancy (functional SVT with aberrancy (functional

bundle branch block)bundle branch block) SVT with underlying bundle branch SVT with underlying bundle branch

blockblock SVT with pre-excitationSVT with pre-excitation

Additional Mimimics of Additional Mimimics of Wide Complex Wide Complex TachycardiasTachycardias

SVT with severe hyperkalemiaSVT with severe hyperkalemia SVT with use of antiarrhythmic SVT with use of antiarrhythmic

agents particularly 1C agentsagents particularly 1C agents SVT with acute MISVT with acute MI

Wide-Complex Wide-Complex TachycardiaTachycardia

Majority are SVT with BBBMajority are SVT with BBB

In higher risk population VT until In higher risk population VT until proven otherwiseproven otherwise

Differentiating VT from SVT Differentiating VT from SVT with Aberrancywith Aberrancy

Leads to correct initial therapyLeads to correct initial therapy Verapamil may ppt hemodynamic Verapamil may ppt hemodynamic

collapsecollapse Hemodynamic status or rate not Hemodynamic status or rate not

a clue to mechanism a clue to mechanism In higher risk population VT until In higher risk population VT until

proven otherwiseproven otherwise ECG criteria for diagnosisECG criteria for diagnosis

The Brugada CriteriaThe Brugada Criteria

Table I.

Diagnosis Of Wide QRS Complex Tachycardia With A Regular Rhythm

Step 1. Is there absence of an RS complex in all precordial leads V1 – V6?

If yes, then the rhythm is VT. Sens 0.21 Spec 1.0

Step 2. Is the interval from the onset of the R wave to the nadir of the Swave greater than 100 msec in any precordial leads?

If yes, then the rhythm is VT. Sens 0.66 Spec 0.98

Step 3. Is there AV dissociation?

If yes, then the rhythm is VT.

Sens 0.82 Spec 0.98

Step 4. Are morphology criteria for VT present? See Table II.

If yes, then the rhythm is VT. Sens 0.99 Spec 0.97

Morphology Criteria for Morphology Criteria for VTVT

Table II.

Morphology Criteria for VT

Right bundle type requires waveform from both V1 and V6.

V1 V6

Monophasic R wave QS or QR

QR or RS R/S <1

Left bundle type requires any of the below morphologies.

V1or V2 V6

R wave > 30 msec

Notched downstroke S wave.

Greater than 60msec nadir S wave.

QR or QS

Adapted from Brugada et al. A new approach to the differential diagnosis of regular tachycardia with a wide QRS complex.Circulation 1991; 83:1649-59.

Therapy for VTTherapy for VT

Stable-chemical or DC Stable-chemical or DC ccardioversion ardioversion

Unstable-DC cardioversionUnstable-DC cardioversion

Amiodarone 150 mg IV over 10 mins, Amiodarone 150 mg IV over 10 mins, max 2.2 gm/24 hrs class IIA max 2.2 gm/24 hrs class IIA recommendationrecommendation

New ACLS AlgorithmNew ACLS Algorithm

VT with Depressed LV FxVT with Depressed LV Fx

Amiodarone drug of choiceAmiodarone drug of choice mortality neutral or beneficialmortality neutral or beneficial Initial dose 150 mg IV. over 10 minsInitial dose 150 mg IV. over 10 mins effective in VF using 300 mg bolus with effective in VF using 300 mg bolus with

improved arrival to hospital.improved arrival to hospital. DC cardioversion always acceptable DC cardioversion always acceptable

optionoption Procainamide contraindicatedProcainamide contraindicated

VT with Preserved LV VT with Preserved LV FxFx

DC cardioversionDC cardioversion Amiodarone 1Amiodarone 1stst line RX according to line RX according to

ACLSACLS ProcainamideProcainamide LidocaineLidocaine Avoid use of combination Avoid use of combination

antiarrhythmic agentsantiarrhythmic agents

AVRT Extranodal Accessory AVRT Extranodal Accessory Pathways and WPW Pathways and WPW

SyndromeSyndrome Extremely symptomatic but rarely Extremely symptomatic but rarely

observedobserved In the presence of AF, VF can occur In the presence of AF, VF can occur

if the refractory period of the if the refractory period of the accessory pathway is <250 msecaccessory pathway is <250 msec

WPWWPW

Not an arrhythmia but a clinical Not an arrhythmia but a clinical syndromesyndrome

ECG: PR<.12 sec, QRS>.10 sec, delta ECG: PR<.12 sec, QRS>.10 sec, delta wavewave

Many types of arrhythmiasMany types of arrhythmias

‘‘Is AVN an integral part or an Is AVN an integral part or an innocent bystander?’innocent bystander?’

WPWWPW

AV Node IntegralAV Node Integral AVRT-OrthodromicAVRT-Orthodromic

AV blocking diagnostic and AV blocking diagnostic and therapeutictherapeutic

AVRT-AntidromicAVRT-AntidromicRegularRegular

AV blocking diagnostic and therapeuticAV blocking diagnostic and therapeutic

WPWWPW

AV Node Innocent BystanderAV Node Innocent Bystander

AFAF

Can be serious problemCan be serious problem

Polymorphic VT Polymorphic VT

Immediate defibrillation Immediate defibrillation

IV Lidocaine , AmiodaroneIV Lidocaine , Amiodarone

Usually result of severe metabolic Usually result of severe metabolic disturbance or cardiac ischemia.disturbance or cardiac ischemia.

Monomorphic VT in Monomorphic VT in Patients with Normal LV FxPatients with Normal LV Fx

No structural heart diseaseNo structural heart disease

Present as palpitations, syncope Present as palpitations, syncope but rarely as sudden deathbut rarely as sudden death

Monomorphic VT in Monomorphic VT in Patients with Normal LV FxPatients with Normal LV Fx

RV outflow tachycardia RV outflow tachycardia LBB morphology inferior axisLBB morphology inferior axis adenosine, Calcium channel , occ beta adenosine, Calcium channel , occ beta

blockersblockers Amenable to AblationAmenable to Ablation

Idiopathic LV tachycardiaIdiopathic LV tachycardia RBB superior axisRBB superior axis Verapamil and adenosine sensitiveVerapamil and adenosine sensitive Amenable to AblationAmenable to Ablation

Torsades de PointesTorsades de Pointes

Polymorphic VT assoc with long QTPolymorphic VT assoc with long QT QTc >440msec , QT > 500 msecQTc >440msec , QT > 500 msec

Frequently initiated after pause Frequently initiated after pause IatrogenicIatrogenic

hypoK, hypoMg, Hypo Ca, Drugs, hypoK, hypoMg, Hypo Ca, Drugs, CombinationCombination

CongenitalCongenital

QT Prolonging or Torsadogenic Drugs

The following drugs have been shown to prolong the QT interval or have documented clinical Torsades de Pointes reported in the literature

Amantadine Quetiapine Aminophylline Quinidine Amiodarone Risperdone Barium Salmeterol Bepridil Thioridazine

ChloralhydrateSparfloxacinChloroquineSumatriptanCiprofloxacinTacrilimusCisaprideTamoxifenSertralineChlorpromazine

DisopyramideTizanideDofetilideTrimethorprimSulfaDoxepineVenlafaxineDroperidolVistarilSotalol

FlecanideFluoxetineFoscarnetFosphentoinGatifloxinHalofantrineHaloperidolIbutilideImipramineIndipamide

IsradapineKetaconazoleLevofloxacinLevomethadylMesoridazineMoexitine/HctzMoxifloxicinNaratripanNicardipineOctreotide

PentamidinePimozideProbucolErythromycinZolmitriptanFelbamateClarithromycinTerfenadineDesipramine

Treatment of Torsades Treatment of Torsades de Pointesde Pointes

Goal to shorten QTGoal to shorten QT

Remove offending agentRemove offending agent

Replete KReplete K

IV Mg even if normal levelIV Mg even if normal level

Treatment of Torsades Treatment of Torsades de Pointesde Pointes

Overdrive pacingOverdrive pacing isoproterenolisoproterenol PacingPacing

DC CardioversionDC Cardioversion Rarely requiredRarely required May be refractoryMay be refractory

Sudden Death with Sudden Death with Normal Normal

LV FxLV Fx

Brugada SyndromeBrugada Syndrome Incompete RBB ST elevation V1V2Incompete RBB ST elevation V1V2

RV DysplasiaRV Dysplasia Delayed RV activationDelayed RV activation Epsilon wave , deep precordial Twave Epsilon wave , deep precordial Twave

inversioninversion

Sudden Death with Sudden Death with Normal Normal LV FXLV FX

Hypertrophic CardiomyopathyHypertrophic Cardiomyopathy Major cause in U.S. in young patients Major cause in U.S. in young patients

without CADwithout CAD Risk factorsRisk factors ICD effectiveICD effective

67 yr old male with prior infarct and LV dysfx 67 yr old male with prior infarct and LV dysfx presents with palpitations and dizziness. BP is presents with palpitations and dizziness. BP is

80/4080/40

A. Synchronized cardioversion for VTA. Synchronized cardioversion for VT B. IV Procainamide for AF with WPW B. IV Procainamide for AF with WPW

syndromesyndrome C. Synchronized cardioversion for C. Synchronized cardioversion for

unstable SVT with aberrancy.unstable SVT with aberrancy. D. IV Amiodarone for SVT with D. IV Amiodarone for SVT with

aberrancy in a patient with LV dysfxaberrancy in a patient with LV dysfx

AnswerAnswer

This patient has VT. An RS interval This patient has VT. An RS interval >100 msec clearly visible. In >100 msec clearly visible. In addition, by history this patient is addition, by history this patient is overwhelmingly likely to present overwhelmingly likely to present with VT with a wide complex rhythmwith VT with a wide complex rhythm

Unstable with relative hypotension Unstable with relative hypotension requiring immediate cardioversion requiring immediate cardioversion as opposed to pharmacologic as opposed to pharmacologic therapy.therapy.

46 yr old alcoholic, on methadone, with 46 yr old alcoholic, on methadone, with schizophrenia. She began feeling dizzy schizophrenia. She began feeling dizzy after starting a fluoroquinalone for a after starting a fluoroquinalone for a

UTIUTI

A. Administer IV Procainamide A. Administer IV Procainamide B. Consult EP for placement of a ICDB. Consult EP for placement of a ICD C. Discontinue antibiotic and C. Discontinue antibiotic and

antipsychotic, treat with IV Mg, and antipsychotic, treat with IV Mg, and consider temporary pacingconsider temporary pacing

D. Administer IV AmiodaroneD. Administer IV Amiodarone

AnswerAnswer

Torsades de Pointes with classic Torsades de Pointes with classic polymorphic VT and prolonged QT polymorphic VT and prolonged QT demonstrated on bottom strip. demonstrated on bottom strip.

Procainamide or amiodarone would Procainamide or amiodarone would worsen this rhythm. worsen this rhythm.

ICD is not indicated .ICD is not indicated .