management of supraventricular tachycardias
DESCRIPTION
Management of Supraventricular Tachycardias. Sandeep K. Jain, M.D. Cardiac Electrophysiology. May 31, 2008. History. Pattern of symptoms / palpitations Triggers Caffeine, tobacco, alcohol Nasal decongestants Emotional events Syncope. Physical Exam. AV dissociation Split S2 - PowerPoint PPT PresentationTRANSCRIPT
Management of Supraventricular Management of Supraventricular TachycardiasTachycardias
Sandeep K. Jain, M.D.Sandeep K. Jain, M.D.Cardiac ElectrophysiologyCardiac Electrophysiology
May 31, 2008
HistoryHistory
Pattern of symptoms / palpitationsPattern of symptoms / palpitations
TriggersTriggers Caffeine, tobacco, alcoholCaffeine, tobacco, alcohol Nasal decongestantsNasal decongestants Emotional eventsEmotional events
SyncopeSyncope
Physical ExamPhysical Exam
AV dissociationAV dissociation
Split S2Split S2
More than one arrhythmia can yield More than one arrhythmia can yield similar exam findings so not as useful for similar exam findings so not as useful for making a diagnosismaking a diagnosis
SVT mechanismsSVT mechanisms Sinus tachycardiaSinus tachycardia Atrial flutterAtrial flutter Atrial fibrillationAtrial fibrillation Junctional tachycardiaJunctional tachycardia Atrial tachycardiaAtrial tachycardia AV node reentry tachycardia (AVNRT)AV node reentry tachycardia (AVNRT) Accessory pathway mediated tachycardia Accessory pathway mediated tachycardia (AVRT)(AVRT)
ECGECG
Are P-waves present?Are P-waves present?What are atrial and ventricular rates and What are atrial and ventricular rates and are they the same ?are they the same ?Regular or Irregular ?Regular or Irregular ?Is the PR or RP constant ?Is the PR or RP constant ?
Carotid Sinus MassageCarotid Sinus MassageIncreases vagal toneIncreases vagal toneSinus slowing and prolongs AV nodal Sinus slowing and prolongs AV nodal refractorinessrefractoriness
Sinus tach – gradually slows then returns Sinus tach – gradually slows then returns to rate prior to massageto rate prior to massageAVNRT or AVRT can terminateAVNRT or AVRT can terminateAT, AF and AFL ventricular response AT, AF and AFL ventricular response slowsslows
Sinus TachycardiaSinus Tachycardia
Gradual change in heart rateGradual change in heart rateNormal P-wave contourNormal P-wave contourConstant PR interval before each QRS Constant PR interval before each QRS unless there is AV block (long RP)unless there is AV block (long RP)Carotid massage or Valsalva will gradually Carotid massage or Valsalva will gradually slow rate and then resume to original rateslow rate and then resume to original rate
Almost always secondaryAlmost always secondaryManagement is to treat underlying causeManagement is to treat underlying cause
Rarely, inappropriate sinus tachycardia in Rarely, inappropriate sinus tachycardia in which case beta-blockers, Ca-blockers can which case beta-blockers, Ca-blockers can be utilizedbe utilizedSinus node reentry tachycardia is abrupt in Sinus node reentry tachycardia is abrupt in onset, anxiety related and can be treated onset, anxiety related and can be treated with RF ablationwith RF ablation
Atrial FlutterAtrial FlutterMacro-reentrant rhythm in the atriaMacro-reentrant rhythm in the atriaUsually associated with underlying heart Usually associated with underlying heart diseasediseaseTypical flutter is in the right atrium and can Typical flutter is in the right atrium and can travel in counterclockwise and clockwise travel in counterclockwise and clockwise directionsdirectionsIncisional scars from prior cardiac surgery / Incisional scars from prior cardiac surgery / congenital abnormalitiescongenital abnormalitiesAtrial rate is typically 250-350 beats/minAtrial rate is typically 250-350 beats/minVentricular rate of 150 – look out for 2:1 Ventricular rate of 150 – look out for 2:1 flutterflutter
Counterclockwise Clockwise
Diagnostic maneuvers - AdenosineDiagnostic maneuvers - Adenosine
Atrial Flutter - ManagementAtrial Flutter - ManagementRate control / anticoagulationRate control / anticoagulation Beta-blocker, Ca-blocker, DigoxinBeta-blocker, Ca-blocker, Digoxin Stroke risk likely not much different than atrial Stroke risk likely not much different than atrial
fibrillationfibrillationCardioversionCardioversion DCCV with low energies possible (50-100J)DCCV with low energies possible (50-100J) Ibutilide successful in 60-90%Ibutilide successful in 60-90%
Prolongs QT and need to be monitored 4-6 hoursProlongs QT and need to be monitored 4-6 hours post administrationpost administration
Overdrive atrial pacing if availableOverdrive atrial pacing if available
Atrial Flutter - ManagementAtrial Flutter - Management
AntiarrhythmicsAntiarrhythmics Class Ia and Ic agents – convert and maintain Class Ia and Ic agents – convert and maintain
sinus rhythmsinus rhythm Class III – amiodarone, sotalol, dofetilideClass III – amiodarone, sotalol, dofetilide
Need to have AV nodal agent on board to Need to have AV nodal agent on board to prevent 1:1 flutter prevent 1:1 flutter Flutter rate slows and allows 1:1 conductionFlutter rate slows and allows 1:1 conduction Class IA agents also have a vagolytic effectClass IA agents also have a vagolytic effect
Flecainide administrationFlecainide administration
Atrial Flutter - ManagementAtrial Flutter - Management
Radiofrequency AblationRadiofrequency Ablation High success rates for typical flutterHigh success rates for typical flutter Atypical circuits can be approached Atypical circuits can be approached
percutaneously with advanced mapping percutaneously with advanced mapping systemssystems
Significant proportion of patients eventually Significant proportion of patients eventually develop atrial fibrillation indicating develop atrial fibrillation indicating underlying substrate is the issueunderlying substrate is the issue
Atrial FibrillationAtrial Fibrillation
Multiple wavelets propagating in different Multiple wavelets propagating in different directions directions No effective atrial contractionNo effective atrial contractionMost common arrhythmiaMost common arrhythmia 1% of those older than 601% of those older than 60 5% of those older than 695% of those older than 69
Mutliple causes – consider mechanical such Mutliple causes – consider mechanical such as from an RA catheteras from an RA catheter
Atrial FibrillationAtrial FibrillationRate vs Rhythm ControlRate vs Rhythm Control No benefit of either if asymptomaticNo benefit of either if asymptomatic
AnticoagulationAnticoagulation Congestive Heart FailureCongestive Heart Failure HypertensionHypertension Age > 65Age > 65 DiabetesDiabetes StrokeStroke
Maintenance of sinus rhythm does not necessarily Maintenance of sinus rhythm does not necessarily eliminate stroke riskeliminate stroke risk
Atrial FibrillationAtrial FibrillationRate ControlRate Control Ca-blocker, Beta-blocker, digoxinCa-blocker, Beta-blocker, digoxin
ConversionConversion DCCVDCCV Class I : Procainamide, Flecainide, PropafenoneClass I : Procainamide, Flecainide, Propafenone Class III: Amiodarone, Sotalol (both poor as converting Class III: Amiodarone, Sotalol (both poor as converting
agents), ibutilideagents), ibutilide
Maintenance of sinus rhythmMaintenance of sinus rhythm Same as above + dofetilideSame as above + dofetilide 50-70% efficacy at 1 year50-70% efficacy at 1 year RF ablation is an emerging toolRF ablation is an emerging tool
Atrial TachycardiaAtrial Tachycardia
Rapid, focal discharge in the atriumRapid, focal discharge in the atriumRate generally 150-200 bpm Rate generally 150-200 bpm P-wave contour different from sinusP-wave contour different from sinusP-waves generally found in second half of P-waves generally found in second half of tachycardia cycle (long RP / short PR)tachycardia cycle (long RP / short PR)
Most commonly in those with structural Most commonly in those with structural heart disease but also seen in those without heart disease but also seen in those without any cardiac abnormalityany cardiac abnormality
Atrial TachycardiaAtrial Tachycardia
Adenosine ResponseAdenosine Response
Terminates tachycardia with an ‘R’ waveTerminates tachycardia with an ‘R’ wave
OROR
Tachycardia persists with AV BlockTachycardia persists with AV Block
Atrial Tachycardia - ManagementAtrial Tachycardia - Management
Beta- and Ca- blockersBeta- and Ca- blockersClass I antiarrhythmics in normal heartsClass I antiarrhythmics in normal heartsClass III antiarrhythmics in abnormal heartsClass III antiarrhythmics in abnormal hearts
Radiofrequency ablation for those who are Radiofrequency ablation for those who are refractory / intolerant to medicationsrefractory / intolerant to medications
AV Node Reentry TachycardiaAV Node Reentry TachycardiaRegular, sudden onset and termination at Regular, sudden onset and termination at rates between 150-250 bpm rates between 150-250 bpm QRS usually normal unless aberrancy is QRS usually normal unless aberrancy is presentpresentReentry within the AV nodeReentry within the AV nodeP-wave seen just prior to or just after the P-wave seen just prior to or just after the QRS complex (Short RP tachycardia)QRS complex (Short RP tachycardia)Usually occurs without any structural heart Usually occurs without any structural heart diseasedisease
AV Node Reentry TachycardiaAV Node Reentry Tachycardia
Antegrade limb is the slow pathwayRetrograde limb is the fast pathway
BaselineBaseline
AV Node Reentry TachycardiaAV Node Reentry Tachycardia
AVNRT 2:1AVNRT 2:1
AV Node Reentry - ManagementAV Node Reentry - Management
IV adenosine, vagal maneuvers, carotid massageIV adenosine, vagal maneuvers, carotid massageCa, Beta-blockers, rarely antiarrhythmicsCa, Beta-blockers, rarely antiarrhythmicsOverdrive atrial or ventricular pacingOverdrive atrial or ventricular pacing
RF ablation is usually treatment of choice for chronic RF ablation is usually treatment of choice for chronic management – cost-effective and high success management – cost-effective and high success rate (~1% incidence of AV block requiring rate (~1% incidence of AV block requiring permanent pacemaker)permanent pacemaker)
Accessory PathwaysAccessory PathwaysMuscular connections outside of the specialized Muscular connections outside of the specialized conduction system connecting the atrium and conduction system connecting the atrium and ventricle while bypassing the AV nodeventricle while bypassing the AV node
Can be manifest (WPW) or concealed (retrograde Can be manifest (WPW) or concealed (retrograde only conduction)only conduction)
Concealed pathways not apparent on ECGConcealed pathways not apparent on ECG
Manifest pathways have a delta wave representing Manifest pathways have a delta wave representing pre-excitation of ventricular tissue prior to pre-excitation of ventricular tissue prior to activation via the His-purkinje systemactivation via the His-purkinje system
Concealed Accessory PathwaysConcealed Accessory Pathways30% of people with SVT referred for EP evaluation30% of people with SVT referred for EP evaluationCan present with syncopeCan present with syncope
Normal baseline 12-lead ECGNormal baseline 12-lead ECG
Orthodromic atrioventricular reentry tachycardia is the Orthodromic atrioventricular reentry tachycardia is the mechanism of SVT (down the AV node and up the mechanism of SVT (down the AV node and up the accessory pathway)accessory pathway)
Will often see a retrograde P-wave during SVT – short Will often see a retrograde P-wave during SVT – short RP unless slowly conducting pathwayRP unless slowly conducting pathway
Orthodromic AV reentry tachycardiaOrthodromic AV reentry tachycardia
Most common arrhythmia with presence of an accessory pathway
Macro-reentrant circuit in which the impulse travels down the AV node andup the accessory pathway
Narrow QRS interval
Accessory PathwaysAccessory Pathways
Accessory PathwaysAccessory Pathways
Response to BBB AberrationResponse to BBB Aberration
Does VA interval increase with development of BBB?Does VA interval increase with development of BBB?
An increase in VA interval indicates the presence and An increase in VA interval indicates the presence and participation of a bypass tract on the side of the blocked participation of a bypass tract on the side of the blocked bundlebundle
Concealed Accessory PathwaysConcealed Accessory Pathways
Same management as for AV node reentrySame management as for AV node reentry
RF ablation should be considered early in RF ablation should be considered early in symptomatic patientssymptomatic patients
Atrial fibrillation in conjunction with a concealed Atrial fibrillation in conjunction with a concealed pathway does not pose a risk of sudden death pathway does not pose a risk of sudden death and IV Ca-blocker not contraindicated as the and IV Ca-blocker not contraindicated as the pathway does not conduct antegradepathway does not conduct antegrade
Pre-excitation syndrome - WPWPre-excitation syndrome - WPWWPW syndrome is when tachycardia is WPW syndrome is when tachycardia is associated with the finding of a delta wave on the associated with the finding of a delta wave on the ECGECGIncidence is 1.5 per thousandIncidence is 1.5 per thousandEbstein’s anomaly associated with multiple Ebstein’s anomaly associated with multiple bypass tractsbypass tractsBaseline ECG findingsBaseline ECG findings PR interval < 120msPR interval < 120ms QRS > 120ms with a slurred, slowly rising onset (delta QRS > 120ms with a slurred, slowly rising onset (delta
wave) and usually normal terminal portion of QRSwave) and usually normal terminal portion of QRS Secondary ST-T changes in opposite direction of delta Secondary ST-T changes in opposite direction of delta
wavewave
Accessory pathwaysAccessory pathways
Left free wall most common, then posteroseptal, right free wall and anteroseptal
Pre-excitation syndromesPre-excitation syndromes
Pre-excitation syndrome - WPWPre-excitation syndrome - WPW
Most common tachycardia is Orthodromic AVRT Most common tachycardia is Orthodromic AVRT as seen in concealed bypass tractsas seen in concealed bypass tracts
Major difference is the capacity for anterograde Major difference is the capacity for anterograde conduction over the pathway during atrial conduction over the pathway during atrial fibrillation (15-30%) or atrial flutter (5%) and thus fibrillation (15-30%) or atrial flutter (5%) and thus the rare incidence of sudden cardiac deaththe rare incidence of sudden cardiac death
Some children lose conduction in the pathway Some children lose conduction in the pathway but usually persists if present at age 5but usually persists if present at age 5
Pre-excitation syndromesPre-excitation syndromes
Pre-excitation syndromesPre-excitation syndromes
WPW - TreatmentWPW - Treatment
ECG abnormality only without arrhythmias ECG abnormality only without arrhythmias may may notnot require EP evaluation require EP evaluation
Symptomatic patients should receive treatmentSymptomatic patients should receive treatment Ablation – Electrical or SurgicalAblation – Electrical or Surgical
Good success rates but with procedural risksGood success rates but with procedural risks PharmacologicPharmacologic
Drugs prolong conduction and/or refractoriness in the AV Drugs prolong conduction and/or refractoriness in the AV node, accessory pathway, or bothnode, accessory pathway, or bothSome agents can suppress premature atrial contractions Some agents can suppress premature atrial contractions which can induce arrhythmiaswhich can induce arrhythmias
WPW - TreatmentWPW - Treatment
Prolong conduction time and refractoriness in AV Prolong conduction time and refractoriness in AV node: node: Adenosine, verapamil, beta-blockers, digoxinAdenosine, verapamil, beta-blockers, digoxin
Prolong refractory period in accessory pathway:Prolong refractory period in accessory pathway: Class IA and IC drugsClass IA and IC drugs
Affect both AP and AV node:Affect both AP and AV node: Class IC drugs, amiodarone, and sotalolClass IC drugs, amiodarone, and sotalol
WPW – Acute EpisodeWPW – Acute EpisodeNormal QRS, regular R-R intervals, retrograde p-Normal QRS, regular R-R intervals, retrograde p-waveswaves Approach same as AVNRT – vagal maneuvers, Approach same as AVNRT – vagal maneuvers,
adenosine, IV Ca-blockeradenosine, IV Ca-blocker Note, atrial fibrillation can occur after drug Note, atrial fibrillation can occur after drug
administration, so external defibrillator back-up should administration, so external defibrillator back-up should be ready be ready
Atrial Fibrillation or Flutter with irregular R-R Atrial Fibrillation or Flutter with irregular R-R intervals and abnormal QRS complexesintervals and abnormal QRS complexes Agents which affect AV node and pathway Agents which affect AV node and pathway
(procainamide with beta blocker)(procainamide with beta blocker) Any signs of hemodynamic impairment – electrical Any signs of hemodynamic impairment – electrical
cardioversion is initial treatment of choicecardioversion is initial treatment of choice
WPW - TreatmentWPW - Treatment
DRUGS NOT TO USE in AF/AFL with WPWDRUGS NOT TO USE in AF/AFL with WPW:: DigoxinDigoxin has varying effects on the accessory pathway has varying effects on the accessory pathway
and can shorten refractoriness and speed ventricular and can shorten refractoriness and speed ventricular response to atrial fibrillationresponse to atrial fibrillation
IV IV LidocaineLidocaine can also increase ventricular response can also increase ventricular response raterate
IV IV VerapamilVerapamil can precipitate ventricular fibrillation in can precipitate ventricular fibrillation in this circumstance (may not happen with oral)this circumstance (may not happen with oral)
CatecholaminesCatecholamines
Supraventricular TachycardiasSupraventricular Tachycardias
Short RP / Long PRShort RP / Long PR
AV node reentryAV node reentryAV reentryAV reentry
Long RP / Short PRLong RP / Short PR
Atrial tachycardiaAtrial tachycardiaSinus node reentrySinus node reentryAtypical AV node Atypical AV node
reentryreentryAV reentry with a slowly AV reentry with a slowly
conducting pathwayconducting pathway