pacemakers jonathan maccabe november 15, 2004 pacemaker indications acquired a/v block in adults...

PacemakersPacemakers

Jonathan MacCabeJonathan MacCabe

November 15, 2004November 15, 2004

Pacemaker IndicationsPacemaker Indications

Acquired A/V block in AdultsAcquired A/V block in Adults– Class I: Class I: There is general agreement that permanent There is general agreement that permanent

pacemakers should be implanted.pacemakers should be implanted. Complete heart blockComplete heart block, permanent or intermittent, at , permanent or intermittent, at

an anatomic level associated with any on of the an anatomic level associated with any on of the following complications:following complications:

– Symptomatic bradycardia. In the presence of complete Symptomatic bradycardia. In the presence of complete heart block symptoms must be presumed to be due the heart block symptoms must be presumed to be due the heart block unless proved otherwise heart block unless proved otherwise

– Congestive heart failure Congestive heart failure – Ectopic rhythms and other medical conditions that require Ectopic rhythms and other medical conditions that require

drugs that suppress the automaticity of escape rhythms drugs that suppress the automaticity of escape rhythms and result in symptomatic bradycardia. and result in symptomatic bradycardia.

– Documented periods of asystole >= 3.0 s or any escape Documented periods of asystole >= 3.0 s or any escape rate <40/min. in symptom free patients rate <40/min. in symptom free patients

– Confusional states that clear with temporary pacing Confusional states that clear with temporary pacing – Post A/V junctional ablation, myotonic dystrophy Post A/V junctional ablation, myotonic dystrophy


Acquired A/V block in AdultsAcquired A/V block in Adults– Class I: Class I: There is general agreement that There is general agreement that

permanent pacemakers should be implanted.permanent pacemakers should be implanted. Second degree A/V blockSecond degree A/V block permanent or permanent or

intermittent, regardless of the type or the site of the intermittent, regardless of the type or the site of the block, with symptomatic bradycardia.block, with symptomatic bradycardia.

Atrial fibrillation, Atrial flutter and rare cases of Atrial fibrillation, Atrial flutter and rare cases of SVT SVT with complete or advanced A/V block, with complete or advanced A/V block, bradycardia and any of the conditions in A1. The bradycardia and any of the conditions in A1. The bradycardia must be unrelated to digitalis or drugs bradycardia must be unrelated to digitalis or drugs known to impair A/V conduction.known to impair A/V conduction.


Acquired A/V block in AdultsAcquired A/V block in Adults– Class II:Class II: Conditions in which permanent pacemakers are Conditions in which permanent pacemakers are

frequently used but there is some divergence of opinion frequently used but there is some divergence of opinion about whether they are needed.about whether they are needed.

Asymptotic complete heart block, permanent or Asymptotic complete heart block, permanent or intermittent, at any anatomic site, with ventricular rates of intermittent, at any anatomic site, with ventricular rates of 40/min. or faster 40/min. or faster

Asymptomatic type ll second degree block, permanent or Asymptomatic type ll second degree block, permanent or intermittent intermittent

Asymptomatic type I second degree block at intra-His or Asymptomatic type I second degree block at intra-His or infra-His levels. infra-His levels.

– Class IIIClass III: Conditions in which there is general agreement : Conditions in which there is general agreement that pacemakers are not necessary.that pacemakers are not necessary.

First degree A/V block First degree A/V block Asymptomatic type 1 second degree A/V block at the supra-Asymptomatic type 1 second degree A/V block at the supra-

his level.his level.


AV Block Associated with Myocardial AV Block Associated with Myocardial Infarction:Infarction:– Class I:Class I: There is general agreement that There is general agreement that

permanent pacemakers should be implanted.permanent pacemakers should be implanted. Persistent advanced second degree A/V block or Persistent advanced second degree A/V block or

complete heart block after acute myocardial complete heart block after acute myocardial infarction with block in he His-Purkinje system infarction with block in he His-Purkinje system

Patients with transient advanced A/V block and Patients with transient advanced A/V block and associated bundle branch block associated bundle branch block


AV Block Associated with Myocardial AV Block Associated with Myocardial Infarction:Infarction:– Class II:Class II: Conditions in which permanent pacemakers Conditions in which permanent pacemakers

are frequently used but there is some divergence of are frequently used but there is some divergence of opinion about whether they are needed.opinion about whether they are needed.

Patients with persistent advanced block in the A/V node Patients with persistent advanced block in the A/V node – Class IIIClass III: Conditions in which there is general : Conditions in which there is general

agreement that pacemakers are not necessary.agreement that pacemakers are not necessary. Transient A/V conduction disturbances in the absence Transient A/V conduction disturbances in the absence

of intraventricular conduction defects of intraventricular conduction defects Transient A/V block in the presence of isolated left Transient A/V block in the presence of isolated left

anterior hemiblock anterior hemiblock Acquired left anterior hemiblock in the absence of A/V Acquired left anterior hemiblock in the absence of A/V

block.block.


Bifasicular and Trifasicular Block Bifasicular and Trifasicular Block (chronic)(chronic)– Class I:Class I: There is general agreement that There is general agreement that

permanent pacemakers should be implanted.permanent pacemakers should be implanted. Bifasicular block with intermittent complete Bifasicular block with intermittent complete

heart block associated with symptomatic heart block associated with symptomatic bradycardia bradycardia

Bifasicular or Trifasicular block with intermittent Bifasicular or Trifasicular block with intermittent type ll second degree A/V block without type ll second degree A/V block without symptoms attributable to the heart block. symptoms attributable to the heart block.


Bifasicular and Trifasicular Block (chronic)Bifasicular and Trifasicular Block (chronic)– Class II:Class II: Conditions in which permanent pacemakers Conditions in which permanent pacemakers

are frequently used but there is some divergence of are frequently used but there is some divergence of opinion about whether they are needed.opinion about whether they are needed.

Bifasicular or trifasicular block with syncope that is not Bifasicular or trifasicular block with syncope that is not proved to be due to complete heart block, but other proved to be due to complete heart block, but other possible causes for syncope are not identifiable possible causes for syncope are not identifiable

Markedly prolonged HV (>100ms) Markedly prolonged HV (>100ms) Pacing-induced infra-His block Pacing-induced infra-His block

– Class III:Class III: Conditions in which there is general Conditions in which there is general agreement that pacemakers are not necessary.agreement that pacemakers are not necessary.

Fasicular block without A/V block or symptoms Fasicular block without A/V block or symptoms Fasicular block with first degree block without symptomsFasicular block with first degree block without symptoms


Sinus Node Dysfunction:Sinus Node Dysfunction:– Class I:Class I: There is general agreement that There is general agreement that

permanent pacemakers should be implanted.permanent pacemakers should be implanted. Sinus node dysfunction with documented Sinus node dysfunction with documented

symptomatic bradycardia. In some patients this will symptomatic bradycardia. In some patients this will occur as a consequence of long-term (essential) drug occur as a consequence of long-term (essential) drug therapy of type and dose for which there are no therapy of type and dose for which there are no acceptable alternatives. acceptable alternatives.

– Class II:Class II: Conditions in which permanent Conditions in which permanent pacemakers are frequently used but there is some pacemakers are frequently used but there is some divergence of opinion about whether they are divergence of opinion about whether they are needed.needed.

Sinus node dysfunction occurring spontaneously or as Sinus node dysfunction occurring spontaneously or as a result of necessary drug therapy, with heart rates a result of necessary drug therapy, with heart rates <40/min. when a clear association between significant <40/min. when a clear association between significant symptoms consistent with bradycardia and the actual symptoms consistent with bradycardia and the actual presence of bradycardia has not been documented. presence of bradycardia has not been documented.


Sinus Node Dysfunction:Sinus Node Dysfunction:– Class III:Class III: Conditions in which there is general Conditions in which there is general

agreement that pacemakers are not necessary.agreement that pacemakers are not necessary. Sinus node dysfunction in asymptomatic Sinus node dysfunction in asymptomatic

patients including those in whom substantial patients including those in whom substantial sinus bradycardia (heart rate < 40/min.) is a sinus bradycardia (heart rate < 40/min.) is a consequence of long-term drug treatment consequence of long-term drug treatment

Sinus node dysfunction in patients in whom Sinus node dysfunction in patients in whom symptoms suggestive of bradycardia are clearly symptoms suggestive of bradycardia are clearly documented not to be associate with a slow documented not to be associate with a slow heart rate.heart rate.


Hypersensitive Carotid Sinus and Hypersensitive Carotid Sinus and Neurovascular SyndromesNeurovascular Syndromes– Class I:Class I: There is general agreement that permanent There is general agreement that permanent

pacemakers should be implanted.pacemakers should be implanted. Recurrent syncope associates with clear, spontaneous Recurrent syncope associates with clear, spontaneous

events provoked by carotid sinus stimulation; minimal events provoked by carotid sinus stimulation; minimal carotid sinus pressure induces asystole of >3 sec. carotid sinus pressure induces asystole of >3 sec. duration in the absence of a medication that depresses duration in the absence of a medication that depresses the sinus node or A/V node the sinus node or A/V node

– Class II:Class II: Conditions in which permanent pacemakers Conditions in which permanent pacemakers are frequently used but there is some divergence of are frequently used but there is some divergence of opinion about whether they are needed.opinion about whether they are needed.

Recurrent syncope without clear, provocative events Recurrent syncope without clear, provocative events and with a hypersensitive cadrioinhibitory response. and with a hypersensitive cadrioinhibitory response.

Syncope with associated bradycardia reproduced by a Syncope with associated bradycardia reproduced by a head-up tilt with or without isoproterenol or other forms head-up tilt with or without isoproterenol or other forms of provocative maneuvers and in which a temporary of provocative maneuvers and in which a temporary pacemaker and second provocative test can establish pacemaker and second provocative test can establish the likely benefits of a permanent pacemaker the likely benefits of a permanent pacemaker


Hypersensitive Carotid Sinus and Hypersensitive Carotid Sinus and Neurovascular SyndromesNeurovascular Syndromes– Class III:Class III: Conditions in which there is general Conditions in which there is general

agreement that pacemakers are not necessary.agreement that pacemakers are not necessary. A hyperactive cardioinhibitory response to carotid A hyperactive cardioinhibitory response to carotid

sinus stimulation in the absence of symptoms. sinus stimulation in the absence of symptoms. Vague symptoms, such s dizziness or light-Vague symptoms, such s dizziness or light-

headedness or both, with a hyperactive headedness or both, with a hyperactive cardioinhibitory response to carotid sinus stimulation. cardioinhibitory response to carotid sinus stimulation.

Recurrent syncope, light-headedness or dizziness in Recurrent syncope, light-headedness or dizziness in the absence of a cardioinhibitory response.the absence of a cardioinhibitory response.

TheNASPE / BPEGGeneric (I.C.H.D.)

The NASPE/BPEG Generic (NBG) CodePosition

Category

LettersUsed

Manufac-turer’sDesignationOnly

I II III

Chamber(s)Paced

Chamber(s)Sensed

Responseto Sensing

Programmability,rate modulation

Antitachy-arrhythmiaFunction(s)

O-None

P-SimpleProgrammable

M-Multi-Programmable

C-Communicating

R-Ratemodulation

O-None

A-Atrium

V-Ventricle

D-Dual(A+V)

S- Single(A or V)

S- Single(A or V)

O-None

A-Atrium

V-Ventricle

D-Dual(A+V)

O-None

T-Triggered

I-Inhibited

D-Dual(T+I)

O-None

P-Pacing(antitachy-arrhythmia)

S-Shock

D-Dual(P+S)

IV V

Codes Are Combined Codes Are Combined To Describe:To Describe: The mode of pacingThe mode of pacing The mode of sensingThe mode of sensing How the pacemaker will respond to the How the pacemaker will respond to the

presence or absence of intrinsic beatspresence or absence of intrinsic beats

- AOOAOO

- AAIAAI

- VOOVOO

- VVIVVI

The NASPE/BPEG Generic (NBG) CodePosition

Category

LettersUsed

Manufac-turer’sDesignationOnly

I II III

Chamber(s)Paced

Chamber(s)Sensed

Responseto Sensing

Programmability,rate modulation

Antitachy-arrhythmiaFunction(s)

O-None

P-SimpleProgrammable

M-Multi-Programmable

C-Communicating

R-Ratemodulation

O-None

A-Atrium

V-Ventricle

D-Dual(A+V)

S- Single(A or V)

S- Single(A or V)

O-None

A-Atrium

V-Ventricle

D-Dual(A+V)

O-None

T-Triggered

I-Inhibited

D-Dual(T+I)

O-None

P-Pacing(antitachy-arrhythmia)

S-Shock

D-Dual(P+S)

IV V

VOO

Ventricular lead

• Ventricular pacing

• Ventricular asynchronous pacing at lower programmed pacing rate

*

• No sensing

AOO

*Atrial lead

• Atrial asynchronous pacing at lower programmed pacing rate

• Atrial pacing

• No sensing

VVI

*Ventricular lead

• Sensed intrinsic QRS inhibits ventricular pacing

• Ventricular pacing

• Ventricular sensing

AAI

*Atrial lead

• Intrinsic P wave inhibits atrial pacing

• Atrial pacing

• Atrial sensing

Dual Chamber Pacing

T / I

*

*Atrial lead

Ventricular Lead

• Pacing in both the atriumand ventricle

• Sensing in both the atrium and ventricle

• Intrinsic P wave and intrinsic QRS can inhibit pacing

• Intrinsic P Wave can “trigger” a paced QRS

DDD

I

DDD pacing DDD pacing

Dual-chamber pacing capable of Dual-chamber pacing capable of pacing and sensing in both the atrial pacing and sensing in both the atrial and ventricular chambers of the heartand ventricular chambers of the heart

4 distinct patterns can be observed 4 distinct patterns can be observed with DDD pacingwith DDD pacing– Sensing in the atrium and sensing in the ventricleSensing in the atrium and sensing in the ventricle– Pacing in the atrium and sensing in the ventriclePacing in the atrium and sensing in the ventricle– Sensing in the atrium and pacing in the ventricle Sensing in the atrium and pacing in the ventricle

(“P wave tracking”)(“P wave tracking”)– Pacing in the atrium and pacing in the ventriclePacing in the atrium and pacing in the ventricle

DDD pacingDDD pacing

Example of sensing in both the Example of sensing in both the atrium and the ventricle atrium and the ventricle (inhibiting in both the atrium and (inhibiting in both the atrium and the ventricle)the ventricle)


Example of pacing in the atrium Example of pacing in the atrium with sensing (inhibition of pacing) with sensing (inhibition of pacing) in the ventriclein the ventricle


Example of sensing in the atrium Example of sensing in the atrium (inhibition of atrial pacing) and pacing (inhibition of atrial pacing) and pacing in the ventriclein the ventricle

Also known as “P wave tracking”Also known as “P wave tracking”


Example of atrial pacing and Example of atrial pacing and ventricular pacing (no inhibition ventricular pacing (no inhibition of pacing)of pacing)

DDD PacingDDD Pacing

Adapts to changes post-implantAdapts to changes post-implant May resemble AAI, VAT, VDD, DVI May resemble AAI, VAT, VDD, DVI

modesmodes Will strive to maintain AV Will strive to maintain AV

synchrony with variable atrial synchrony with variable atrial rates and AV conductionrates and AV conduction

Cardiac Output = Stroke Volume x Heart Rate

AV SynchronyAV Synchrony

Facilitates venous returnFacilitates venous return Increases LVEDPIncreases LVEDP Maintains appropriate opening and Maintains appropriate opening and

closing closing of A-V valvesof A-V valves

Loss of AV Loss of AV SynchronySynchrony

Pacemaker SyndromePacemaker Syndrome

Shortness of breathShortness of breath FatigueFatigue HeadacheHeadache SyncopeSyncope VertigoVertigo CHF, Pulmonary CHF, Pulmonary

EdemaEdema

DizzinessDizziness PalpitationsPalpitations Pulsations in the Pulsations in the

neckneck Chest painChest pain Near SyncopeNear Syncope ConfusionConfusion

Loss of atrial Loss of atrial contributioncontribution

Decrease in stroke Decrease in stroke volumevolume

Decrease in cardiac Decrease in cardiac outputoutput

Decrease in cerebral Decrease in cerebral perfusionperfusion

Decrease in coronary Decrease in coronary blood flowblood flow

Dual-chamber pacingDual-chamber pacing Normal atrial sensing Normal atrial sensing

& capture& capture Appropriate AV DelayAppropriate AV Delay

HemodynamicHemodynamic Penalties From Penalties From

Loss Of AV Loss Of AV SynchronySynchrony

Treatment of Pacemaker Syndrome

Goals of Choosing a Goals of Choosing a Pacing ModePacing Mode

Desire to maintain AV synchronyDesire to maintain AV synchrony– DDD mode is best to provide AV DDD mode is best to provide AV

synchronysynchrony Preservation of AV synchrony Preservation of AV synchrony

requires:requires:– Viable atrium andViable atrium and– Patient must not have chronic/permanent Patient must not have chronic/permanent

atrial tachyarrhythmiasatrial tachyarrhythmias

Optimal Pacing Mode Decision Tree

Pacemaker is indicated

What is the condition of the SA Node?

Is the patientchronotropically incompetent?

VVIR VVI

VentricularPacing


DDDR

DDD

AV Synchrony

Is AV conductionadequate?



DDDR DDD AAIR AAI

AV Synchrony

Y N

N Y

Y N

Y NY N

Chronic atrial fibrillationunexcitable atrium Normal or sinus

bradycardia

AV Synchrony - DDD(R)


What is the condition of the SA node??

Is AV conductionadequate?


DDDR DDD

N

Y N

Normal or sinusbradycardia

• Benefits– AV synchrony– Normal sinus response

• Risks– Loss of AV conduction

Ventricular Pacing


What is the condition of the SA node?


VVIR VVI

Y N

Chronic atrial fibrillationunexcitable atrium

• Benefits– Maintain minimum cardiac output– Single-lead implantation

• Risks– Loss of AV synchrony– Retrograde conduction– Increased incidence of atria arrhythmias

Rate Modulation/Rate Rate Modulation/Rate Responsive ModeResponsive Mode

Rate Rate Responsiveness/Adaptive-Responsiveness/Adaptive-Rate PacingRate Pacing In Rate Responsive pacing (modes ending with In Rate Responsive pacing (modes ending with

“R”), sensor(s) in pacemaker are used to detect “R”), sensor(s) in pacemaker are used to detect changes in physiologic needs and increase the changes in physiologic needs and increase the pacing rate accordinglypacing rate accordingly

The sensorThe sensor– Sensors are used to detect changes in metabolic demandSensors are used to detect changes in metabolic demand– Sensors sense motion (piezoelectric crystal or Sensors sense motion (piezoelectric crystal or

accelerometer) or use a physiologic indicator, e.g., accelerometer) or use a physiologic indicator, e.g., minute ventilation minute ventilation

The algorithm The algorithm – Within the software of the pacemaker Within the software of the pacemaker – Uses the input from the sensor to determine the Uses the input from the sensor to determine the

appropriate paced heart rate for the activityappropriate paced heart rate for the activity

DDDR PacingDDDR Pacing

Example of Dual-Chamber Rate-Example of Dual-Chamber Rate-Responsive pacingResponsive pacing

DDDRDDDR

A DDDR pacemaker has two or A DDDR pacemaker has two or more indicators of a patient’s more indicators of a patient’s metabolic need:metabolic need:– Sinus node – the best indicator, as it Sinus node – the best indicator, as it

is physiologicis physiologic– Input from the sensor(s) within the Input from the sensor(s) within the

pacemakerpacemaker

Pacemaker Timing Pacemaker Timing and Functionand Function

LRL LRL LRL

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

Lower Rate LimitLower Rate Limit

LRL 60 ppm

VTL 120 ppm

AVD 150 ms

PVARP 250 msDDD-09

Ventricular Ventricular Tachycardia Limit Tachycardia Limit (Upper Rate Limit)(Upper Rate Limit)

VTL VTL VTL

AV AV AV

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

A-V DelayA-V Delay

AVD AVDAVD

AVsAVp

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

Avs 150 ms

Min. Adap. A-V 88 ms

PVARP 250 ms

A-V DelayA-V Delay

AVD PVARPTARP

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

TARP 450 ms

Atrial Refractory Atrial Refractory PeriodsPeriods

PVARP = Post Ventricular Activation Refractory Period

TARP = Total Atrial Refractory Period

TARP = AVD + PVARP

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

AVs 150 ms


PVARP 250 ms DDD-16

Atrial Refractory Atrial Refractory PeriodsPeriods

Note: this P wave does not trigger ventricular pacing because it falls within the PVARP

PVARP

Pacemaker Pacemaker MalfunctionsMalfunctions

DDD-22

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

Failure to CaptureFailure to Capture

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 msDDD-23

Failure to CaptureFailure to Capture

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

TARP 450 ms DDD-02

Failure to SenseFailure to Sense

LRL 60 ppm

VTL 120 ppm

AVD 150 ms

PVARP 350 ms

DDD-12

Pacemaker Associated Pacemaker Associated Heart BlockHeart Block

LRL 60 ppm

VTL 120 ppm

AVD 150 ms

PVARP 250 ms

DDD-14

Pacemaker Associated Pacemaker Associated Heart BlockHeart Block

Note: AVD is extended to preserve the upper rate limit

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

AVs 150 ms


PVARP 250 ms DDD-15

““Pacemaker Pacemaker Wenkebach”Wenkebach”

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

AVs 150 ms


PVARP 250 msDDD-17

Pacemaker Associated Pacemaker Associated TachycardiaTachycardia

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

AVs 150 ms


PVARP 250 msDDD-18

Pacemaker Associated Pacemaker Associated TachycardiaTachycardia

continuous

LRL 60 ppm AVs 150 ms

VTL 100 ppm Min. Adap. A-V 88 ms

AVp 200 ms PVARP 250 ms

DDD-19

LRL 60 ppm

VTL 120 ppm

AVp 200 ms

AVs 150 ms


PVARP 250 ms DDD-20

OversensingOversensing

LRLLRL 60 ppm 60 ppm

VTLVTL 120 ppm120 ppm

AVpAVp 200 ms200 ms

AVsAVs 150 ms150 ms

Min. Adap. A-VMin. Adap. A-V 88 ms 88 ms

PVARPPVARP 250 ms250 ms DDD-21

Oversensing with Oversensing with Safety PacingSafety Pacing

Is This a Pacemaker Is This a Pacemaker Malfunction?Malfunction?

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 msDDD-08

Normal DDD PacingNormal DDD Pacing

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

TARP 450 ms DDD-01


LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 msDDD-07


LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 msDDD-05

FusionFusion

DDD-04

LRL 60 ppm

VTL 120 ppm

AVD 200 ms

PVARP 250 ms

TARP 450 MS

Safety PacingSafety Pacing

The EndThe End

pacemakers jonathan maccabe november 15, 2004 pacemaker indications acquired a/v block in adults...

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