preanesthetic evaluation of pacemakers 101 david a. cross, m.d. department of anesthesiology scott...

Preanesthetic Evaluation of Preanesthetic Evaluation of Pacemakers 101Pacemakers 101

David A. Cross, M.D.David A. Cross, M.D.Department of AnesthesiologyDepartment of Anesthesiology

Scott and White Memorial Hospital and ClinicScott and White Memorial Hospital and ClinicAssociate Professor, AnesthesiologyAssociate Professor, Anesthesiology

TX A&M Health Sciences CenterTX A&M Health Sciences CenterTemple, TXTemple, TXSHAZAM!!


ASA Practice Advisory:ASA Practice Advisory:

Anesthesiology Anesthesiology 2005;203:186.2005;203:186.


For information regarding a specific For information regarding a specific pacemaker during or after pacemaker during or after interrogation, go to:interrogation, go to:

www.medtronicconnect.com

and download their FREE and download their FREE “Pacemaker and ICD “Pacemaker and ICD Encyclopedia” into your handheld. Encyclopedia” into your handheld. Both Palm OS and Windows Both Palm OS and Windows versions are there.versions are there.


Why do we care? After all, the Why do we care? After all, the pacemaker is working fine and pacemaker is working fine and has been for…for…well… for how has been for…for…well… for how long now?? long now??

AHA!! Could that be a problem??AHA!! Could that be a problem??


Why ignore the pacemaker?Why ignore the pacemaker?““Too much trouble, and, besides…”Too much trouble, and, besides…”

““Been doing it this way for 20+ years… Been doing it this way for 20+ years… and…”and…”

““I don’t believe in…”I don’t believe in…”

““Nothing ever happens…”Nothing ever happens…”

““Not my problem, it’s cardiology’s Not my problem, it’s cardiology’s problem.”…and we all know cardiology problem.”…and we all know cardiology will will bail us out anytime, anywhere, on bail us out anytime, anywhere, on demand!demand!


Let me remind

you what part of your

anatomy is prominently exposed when your

head is buried in the sand!

IndicationsIndications

Levels of EvidenceLevels of EvidenceLevel I – solid medical evidence or Level I – solid medical evidence or general agreement that the procedure or general agreement that the procedure or treatment is beneficial, useful, and treatment is beneficial, useful, and effectiveeffectiveLevel II – conflicting evidence or Level II – conflicting evidence or divergence of opinion regarding a divergence of opinion regarding a procedure’s or treatment’s usefulness procedure’s or treatment’s usefulness and / or efficacyand / or efficacyLevel III – evidence or general agreement Level III – evidence or general agreement that a procedure or treatment is not that a procedure or treatment is not useful and in some cases may be harmful.useful and in some cases may be harmful.


Level ILevel I

Neurogenic syncope caused by light Neurogenic syncope caused by light carotid carotid stimulationstimulation

Symptomatic 2Symptomatic 2ndnd or 3 or 3rdrd degree A-V block degree A-V block

Asymptomatic 3Asymptomatic 3rdrd degree A-V block with degree A-V block with HRs 40 HRs 40 or belowor below

Fascicular blocks with intermittent Fascicular blocks with intermittent symptomatic 3symptomatic 3rdrd degree block or Type II degree block or Type II 22ndnd degree block with or without degree block with or without symptomssymptoms


Level I (con’t)Level I (con’t)

Sinus node dysfunction with Sinus node dysfunction with documented documented bouts of bouts of symptomatic bradycardiasymptomatic bradycardia

Cardiomyopathy with Cardiomyopathy with symptomatic bouts of symptomatic bouts of AV node AV node dysfunction or AV blocks with dysfunction or AV blocks with symptomatic bradycardiassymptomatic bradycardias


Level IILevel II

Asymptomatic 2Asymptomatic 2ndnd degree or 3 degree or 3rdrd degree with degree with HR > 40HR > 40

Sinus node dysfunction with HR Sinus node dysfunction with HR > 40> 40

Dilated cardiomyopathy with EF Dilated cardiomyopathy with EF <35%, QRS >130 ms, and Class <35%, QRS >130 ms, and Class 3-4 CHF3-4 CHF


Atrial Fibrillation:Atrial Fibrillation:?? VVI with history of ventricular ?? VVI with history of ventricular

bradycardiabradycardia?? DDDR with rate set at rate high ?? DDDR with rate set at rate high enough enough to try and inhibit the to try and inhibit the occurrence of AF.occurrence of AF.

Evidence suggestive of longer Evidence suggestive of longer bouts of bouts of NSR and fewer embolic NSR and fewer embolic phenomena. phenomena. May have DDDR set May have DDDR set to VVIR with a to VVIR with a mode switch.mode switch.


We’re concerned about five broad intra-We’re concerned about five broad intra-operative possibilities regarding the operative possibilities regarding the pacemaker:pacemaker:

1)1) Will it quit during surgery?Will it quit during surgery?

2)2) Will the patient die if it quits?Will the patient die if it quits?

3)3) Will the pacemaker cause a Will the pacemaker cause a dysrhythmia?dysrhythmia?

4)4) Will the patient get shocked if he / she Will the patient get shocked if he / she has an ICD?has an ICD?

5)5) Will the ICD cause a dysrhythmia?Will the ICD cause a dysrhythmia?


So, we need to know:So, we need to know:1)1) What kind of pacemaker does What kind of pacemaker does

the patient have?the patient have?2)2) To what mode it is set?To what mode it is set?3)3) Is it functioning properly?Is it functioning properly?4)4) Does it need to be reset to a Does it need to be reset to a

different mode for surgery?different mode for surgery?5)5) Is it likely to stop functioning Is it likely to stop functioning

during surgery?during surgery?


6)6) What is the patient’s underlying What is the patient’s underlying rhythm?rhythm?

7)7) Is there an ICD?Is there an ICD?

8)8) Does the ICD need to be inhibited Does the ICD need to be inhibited or turned off?or turned off?

9)9) What is the magnet response of What is the magnet response of the pacemaker?the pacemaker?

10)10) Will a magnet be needed or will it Will a magnet be needed or will it help?help?

Types of PacemakersTypes of PacemakersMany types, but at S&W, mostly two types, Many types, but at S&W, mostly two types,

with an occasional third.with an occasional third.

1)1) St. JudeSt. Jude

2)2) MedtronicMedtronic

3)3) Guidant (Boston Scientific) (see these Guidant (Boston Scientific) (see these rarely)rarely)

If the pacemaker was put in at S&W before If the pacemaker was put in at S&W before a couple of years ago, it is most likely a a couple of years ago, it is most likely a Medtronic. More recently, it may be a Medtronic. More recently, it may be a St. Jude. We occasionally see Guidants St. Jude. We occasionally see Guidants placed elsewhere.placed elsewhere.

How To Tell the TypeHow To Tell the Type

1)1) Take a chance—pick an Take a chance—pick an interrogator. If it senses the interrogator. If it senses the pacemaker, that’s the brand. pacemaker, that’s the brand. Won’t hurt the pacemaker if you Won’t hurt the pacemaker if you try to interrogate it with the wrong try to interrogate it with the wrong interrogator. It just won’t sense it.interrogator. It just won’t sense it.

2)2) Take a Chest X-ray. Every brand Take a Chest X-ray. Every brand has an X-ray identifiable marker has an X-ray identifiable marker for its brand of pacemaker.for its brand of pacemaker.

Preanesthetic EvaluationPreanesthetic EvaluationPresently, we only have two Presently, we only have two

interrogators available to us in the interrogators available to us in the OR area: St. Jude and Medtronic. OR area: St. Jude and Medtronic.

If neither of these will interrogate the If neither of these will interrogate the pacemaker, you’ll have to call the pacemaker, you’ll have to call the pacemaker clinic (4-9155 / 4-1083) pacemaker clinic (4-9155 / 4-1083) to do the interrogation.to do the interrogation.

Some pacemakers are wireless, and Some pacemakers are wireless, and the interrogator will ask you to the interrogator will ask you to remove the magnet head to remove the magnet head to interrogate.interrogate.

Pacemaker NomenclaturePacemaker Nomenclature

II IIII IIIIII IVIV VVChambeChamber Pacedr Paced

ChambeChamber Sensedr Sensed

Response Response to Sensingto Sensing

Rate Rate Modulation, Modulation, ProgrammabilitProgrammabilityy

Anti-Anti-tachycardia tachycardia FeaturesFeatures

A=AtriuA=Atriumm

A=AtriuA=Atriumm

T=TriggerT=Triggereded

P=Simple Rate P=Simple Rate and Outputand Output

P=PacingP=Pacing

V=VentV=Vent V=VentV=Vent I=InhibiteI=Inhibitedd

M=Multi-M=Multi-programmableprogrammable

S=ShockS=Shock

D=DualD=Dual D=DualD=Dual D=DualD=Dual R=Rate R=Rate AdaptiveAdaptive

D=DualD=Dual

O=NoneO=None O=NoneO=None O=NoneO=None C=CommunicatC=Communicating (telemetry)ing (telemetry)

O=NoneO=None

Defibrillator Defibrillator NomenclatureNomenclature

Position Position II

Position Position IIII

Position Position IIIIII

Position Position IVIV

(or use (or use pacemaker pacemaker

code)code)

Shock Shock ChamberChamber

AntitachycarAntitachycardia Pacing dia Pacing ChambersChambers

Tachycardia Tachycardia DetectionDetection

AntibradycarAntibradycardia Pacing dia Pacing ChambersChambers

O=noneO=none O=noneO=none EE=Electric=Electricalal

O=noneO=none

A=AtrialA=Atrial A=AtrialA=Atrial HH=Hemod=Hemodyn.yn.

A=AtrialA=Atrial

V=VentriV=Ventriclecle



D=DualD=Dual D=DualD=Dual D=DualD=Dual

Pacemaker Pacemaker NomenclatureNomenclature

Examples:Examples:

VOO – ventricle asynchronously paced VOO – ventricle asynchronously paced at set at set rate.rate.

VVI – Ventricle paced, Ventricle VVI – Ventricle paced, Ventricle sensed, sensed, pacing inhibited if pacing inhibited if sensed.sensed.

VVIR – Ventricle paced, Ventricle VVIR – Ventricle paced, Ventricle sensed, sensed, pacing inhibited if pacing inhibited if sensed, rate sensed, rate response to response to exercise.exercise.

Pacemaker Pacemaker NomenclatureNomenclature

DOO – asynchronous Atrio-Ventricular DOO – asynchronous Atrio-Ventricular pacing pacing at preset rate.at preset rate.

DDD – Atrium and Ventricle DDD – Atrium and Ventricle synchronously synchronously paced, both paced, both sensed, pacing sensed, pacing triggered in triggered in each chamber if each chamber if underlying pacer not detectedunderlying pacer not detected

DDDR – as above, with rate DDDR – as above, with rate responsiveness to responsiveness to exercise.exercise.

Rate-variable…how?Rate-variable…how?

Most will detect respiratory rate Most will detect respiratory rate variability and vary the heart rate variability and vary the heart rate in response to an increase in in response to an increase in ventilatory rate.ventilatory rate.

Suggested by some to increase the Suggested by some to increase the programmed HR in the programmed HR in the pacemaker for surgery to pacemaker for surgery to compensate for metabolic compensate for metabolic demand.demand.

Pacemaker ModePacemaker Mode

Problems with asynchronous mode Problems with asynchronous mode pacing:pacing:

Works against atria and a-v valve Works against atria and a-v valve openingopening

Lowers cardiac output unless:Lowers cardiac output unless:

in AFin AF

33rdrd degree block with a VERY degree block with a VERY slow vent slow vent rate.rate.

Intraoperative Intraoperative MonitoringMonitoring

Always have the monitor setup set Always have the monitor setup set to “Monitor,” and not “ESU,” so to “Monitor,” and not “ESU,” so you can see the pacing spike. you can see the pacing spike. May cause problems if there is May cause problems if there is undue interference in the room, undue interference in the room, or when the surgeon uses a or when the surgeon uses a unipolar electrocautery.unipolar electrocautery.

The InterrogationThe Interrogation

Device DataDevice Data

Device – Patient Interaction DataDevice – Patient Interaction Data

Patient DataPatient Data

The InterrogationThe Interrogation

Intraoperative ProblemsIntraoperative Problems

ElectrocauteryElectrocautery

Can reprogram the pacemakerCan reprogram the pacemaker

Can inhibit the pacemakerCan inhibit the pacemaker

Can cause an ICD to perform Can cause an ICD to perform tachytherapytachytherapy

Can cause pacemaker damage (very rare)Can cause pacemaker damage (very rare)

Can induce VFCan induce VF

Can cause a rise in capture threshold by Can cause a rise in capture threshold by causing causing a burn at the site of lead a burn at the site of lead implantation (rare)implantation (rare)

Problematic SolutionsProblematic Solutions

Magnets are useful, but not Magnets are useful, but not utopian!utopian!

Many pacemakers will respond Many pacemakers will respond by resetting by resetting to an “OO” mode to an “OO” mode with a magnet at a HR with a magnet at a HR acceptable (65-85).acceptable (65-85).

NOT ALL….that’s why you need NOT ALL….that’s why you need to to download the “Pacemaker download the “Pacemaker Encyclopedia.”Encyclopedia.”

Problematic SolutionsProblematic SolutionsMagnet rate response in an “OO” Magnet rate response in an “OO”

mode dependent on brand and mode dependent on brand and battery life.battery life.

Magnets will cause most DDDs to Magnets will cause most DDDs to convert to DOO at about 85 with a convert to DOO at about 85 with a BOL (beginning of life) battery, and BOL (beginning of life) battery, and to VOO at a rate of about 65 at ERI to VOO at a rate of about 65 at ERI (effective replacement interval) is (effective replacement interval) is reached to conserve power.reached to conserve power.

Manufacturer variability…download Manufacturer variability…download the encyclopedia!the encyclopedia!


Useful to put a magnet on the patient’s Useful to put a magnet on the patient’s pacemaker IF:pacemaker IF:

Pacemaker dependentPacemaker dependent

Surgeon won’t or can’t use a bipolar Surgeon won’t or can’t use a bipolar ESUESU

Cannot place the pad distal to the Cannot place the pad distal to the unipolar unipolar ESUESU

Closer than the general “6-inch” rule.Closer than the general “6-inch” rule.

There is NO ICDThere is NO ICD


Magnet potentially harmful IF:Magnet potentially harmful IF:

The patient’s underlying rhythm is very The patient’s underlying rhythm is very close to close to the pacemaker’s setting. If you the pacemaker’s setting. If you reprogram reprogram the pacemaker to an “OO” the pacemaker to an “OO” mode, you might mode, you might cause a pacemaker cause a pacemaker stimulus at the wrong point stimulus at the wrong point on the on the patient’s cycle and induce VT or VF.patient’s cycle and induce VT or VF.

There is an ICD. All ICDs are inhibited by There is an ICD. All ICDs are inhibited by the the magnet (Guidant problem), but no magnet (Guidant problem), but no pacemakers pacemakers with ICDs are affected by with ICDs are affected by the magnet.the magnet.


If the patient’s underlying rhythm is If the patient’s underlying rhythm is close to the pacemaker’s set close to the pacemaker’s set rhythm, leave the pacemaker alone. rhythm, leave the pacemaker alone. If it’s inhibited, it won’t matter.If it’s inhibited, it won’t matter.

Consider placing external pacemaker Consider placing external pacemaker electrodes just in case.electrodes just in case.


Alternatively, reprogram Alternatively, reprogram pacemaker to AAI with the pacemaker to AAI with the output very low so it doesn’t output very low so it doesn’t capture.capture.

Problematic if patient’s underlying Problematic if patient’s underlying rhythm becomes severely rhythm becomes severely bradycardic intraoperatively.bradycardic intraoperatively.


As a general rule, disable or turn off As a general rule, disable or turn off all ICDs prior to surgery by all ICDs prior to surgery by reprogramming or by using a reprogramming or by using a magnet.magnet.

Can read ESU as VF and shock Can read ESU as VF and shock patient. Hurts like hell if patient patient. Hurts like hell if patient awake, and can cause real VT, VF, or awake, and can cause real VT, VF, or Torsade des Pointes if happens on Torsade des Pointes if happens on the wrong part of the patient’s the wrong part of the patient’s underlying cycle.underlying cycle.


Many ICDs have built-in VOO Many ICDs have built-in VOO pacemakers. If the patient has pacemakers. If the patient has no pacemaker implanted, the no pacemaker implanted, the built-in ICD pacemaker will built-in ICD pacemaker will become active in the event that a become active in the event that a shock is delivered and the shock is delivered and the patient goes into asystole.patient goes into asystole.

Rate is usually minimal, at about Rate is usually minimal, at about 40 or so.40 or so.


Guidant ICDs – CAREFUL!!Guidant ICDs – CAREFUL!!

1) Some Guidants were installed 1) Some Guidants were installed with the with the magnet response magnet response switch turned OFF. switch turned OFF. Placing a Placing a magnet on the ICD may not magnet on the ICD may not turn off the ICD.turn off the ICD.

2) How to tell? The tell-tale 2) How to tell? The tell-tale beeping soundbeeping sound


Most Guidant ICDs have a very low volume Most Guidant ICDs have a very low volume ‘beeping’ sound in conjunction with the ‘beeping’ sound in conjunction with the HR. If you place a magnet over the ICD for HR. If you place a magnet over the ICD for 90 sec or so, you will hear the tone convert 90 sec or so, you will hear the tone convert to a constant tone IF the ICD has been to a constant tone IF the ICD has been effectively disabled by the magnet. You can effectively disabled by the magnet. You can then remove the magnet and it’ll stay then remove the magnet and it’ll stay disabled.disabled.

At the end of the case, do the reverse. The At the end of the case, do the reverse. The magnet will restore the beeping sound magnet will restore the beeping sound after about 90 sec IF the ICD has been re-after about 90 sec IF the ICD has been re-enabled. You can then remove the magnet.enabled. You can then remove the magnet.


If you have:If you have:

1) a sensing pacemaker and ICD, 1) a sensing pacemaker and ICD,

2) the patient is pacemaker 2) the patient is pacemaker dependent, anddependent, and

3) there is no way to prevent the ESU 3) there is no way to prevent the ESU current from going across the current from going across the

pacemaker, pacemaker,

it must be reprogrammed to the ICD off, it must be reprogrammed to the ICD off, and the pacemaker to an “OO” mode.and the pacemaker to an “OO” mode.

Other Surgery-related Other Surgery-related ProblemsProblems

LithotripsyLithotripsyKeep the generator out of shock pathKeep the generator out of shock path

ECTECTConvert to non-sensing mode, unless set Convert to non-sensing mode, unless set

close to patient’s underlying rhythmclose to patient’s underlying rhythmNerve Stimulator, TENS Nerve Stimulator, TENS

Watch placement with regard to Watch placement with regard to generatorgenerator

MRIMRIAbsolute contraindication to MRIAbsolute contraindication to MRI

CASESCASES

CasesCases

72 year-old male with DDDR 72 year-old male with DDDR pacemaker pacing at 74/min. pacemaker pacing at 74/min. Patient’s underlying rhythm is Patient’s underlying rhythm is sinus at 68/min. Patient is to sinus at 68/min. Patient is to have a left carotid have a left carotid endarterectomy.endarterectomy.

CasesCases

68 year old male with DDDR 68 year old male with DDDR pacemaker and ICD to have a pacemaker and ICD to have a mediastinoscopy, bronchoscopy, mediastinoscopy, bronchoscopy, and possible right upper and possible right upper lobectomy. Patient is pacemaker lobectomy. Patient is pacemaker dependent with no underlying dependent with no underlying ventricular rate during the ventricular rate during the pacemaker test inhibition (2 pacemaker test inhibition (2 sec). sec).

CasesCases

55 year old female having a left 55 year old female having a left hip replacement. She has hip replacement. She has chronic atrial fibrillation with a chronic atrial fibrillation with a VVI pacemaker in place pacing at VVI pacemaker in place pacing at 70 / min. Her underlying rhythm 70 / min. Her underlying rhythm is AF with an irregularly is AF with an irregularly irregular ventricular response irregular ventricular response rate of 40-70.rate of 40-70.

CasesCases

82 year old man with a 10% EF to 82 year old man with a 10% EF to undergo CABG. He has a DDIR undergo CABG. He has a DDIR biventricular pacemaker in. His biventricular pacemaker in. His underlying rhythm is AF with no underlying rhythm is AF with no detectable ventricular activity for detectable ventricular activity for the duration of pacemaker the duration of pacemaker inhibition on testing. inhibition on testing.

CasesCases

75 year old woman in atrial 75 year old woman in atrial fibrillation with a DDIR fibrillation with a DDIR pacemaker functioning as a VVIR pacemaker functioning as a VVIR at 60 / min to undergo a Maze at 60 / min to undergo a Maze Procedure for her AF and CABG.Procedure for her AF and CABG.


QUESTIONS??QUESTIONS??

preanesthetic evaluation of pacemakers 101 david a. cross, m.d. department of anesthesiology scott...

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