temporary pacemaker slides

PacemakersPacemakers

PacemakersPacemakers

Pacemakers are the electronic Pacemakers are the electronic devices that can be used to devices that can be used to initiate the heartbeat when the initiate the heartbeat when the heart’s intrinsic electrical system heart’s intrinsic electrical system cannot effectively generate a cannot effectively generate a rate adequate to support cardiac rate adequate to support cardiac outputoutput

Types of PacemakerTypes of Pacemaker

Temporary pacemakerTemporary pacemaker

Permanent pacemakerPermanent pacemaker

Temporary PacemakerTemporary Pacemaker

Temporary Pacemakers can be Temporary Pacemakers can be used temporarily , either used temporarily , either supportively or prophylactically, supportively or prophylactically, until the condition responsible until the condition responsible for the rate or conduction for the rate or conduction disturbance resolves .disturbance resolves .

IndicationsIndications

BradycardiaBradycardia• Sinus bradycardia and arrestSinus bradycardia and arrest• Sick sinus syndromeSick sinus syndrome• Heart blocksHeart blocks TachydysrhythmiasTachydysrhythmias• SupraventricularSupraventricular• VentricularVentricular Permanent pacemaker failurePermanent pacemaker failure Support cardiac output after cardiac surgerySupport cardiac output after cardiac surgery Diagnostic studiesDiagnostic studies• Electrophysiological studiesElectrophysiological studies• Atrial electrogramAtrial electrogram

The Pacemaker SystemThe Pacemaker System

A simple electrical circuit A simple electrical circuit consisting of consisting of

PULSE GENERATORPULSE GENERATOR

PACING LEAD PACING LEAD

Pulse GeneratorPulse Generator

Pacing pulse generatorPacing pulse generator

The pulse generator is designed to The pulse generator is designed to generate an electrical current that generate an electrical current that travels through pacing lead and exits travels through pacing lead and exits through electrode that is in direct through electrode that is in direct contact with the heart. This electrical contact with the heart. This electrical current initiates a myocardial current initiates a myocardial depolarization.depolarization.

The power source for a temporary The power source for a temporary external pulse generator is standard external pulse generator is standard 9-volt alkaline battery inserted into 9-volt alkaline battery inserted into the generatorthe generator

Pacing Lead SystemPacing Lead System

The pacing lead used for The pacing lead used for temporary pacing may be bipolar temporary pacing may be bipolar or unipolar or unipolar

Bipolar Pacing SystemBipolar Pacing System

In bipolar pacing system, two In bipolar pacing system, two electrodes (positive and electrodes (positive and negative) are located within the negative) are located within the heartheart

Bipolar Pacing SystemBipolar Pacing System The bipolar lead used in the The bipolar lead used in the

transvenous pacing as two transvenous pacing as two electrodeselectrodes

on one catheter.on one catheter. The distal , or negative , electrode The distal , or negative , electrode

is at the tip of the pacing lead and is at the tip of the pacing lead and is in the direct contact with the is in the direct contact with the heart, usually inside the right heart, usually inside the right atrium or ventricle. atrium or ventricle.

Bipolar pacing systemBipolar pacing system

Approximately 1 cm from the Approximately 1 cm from the negative electrode is a positive negative electrode is a positive electrode .electrode .

The negative electrode is attached The negative electrode is attached to the negative terminal, and the to the negative terminal, and the positive electrode is attached to positive electrode is attached to the positive terminal of the pulse the positive terminal of the pulse generator, either directly or via a generator, either directly or via a bridging cablebridging cable

Bipolar pacing systemBipolar pacing system

An epicardial lead system is often used for An epicardial lead system is often used for temporary pacing after cardiac surgerytemporary pacing after cardiac surgery

The bipolar epicardial lead system has two The bipolar epicardial lead system has two separate insulated wires (one negative separate insulated wires (one negative and one positive) that are loosely secured and one positive) that are loosely secured with sutures to the cardiac chambers to be with sutures to the cardiac chambers to be paced. Both electrodes are in contact with paced. Both electrodes are in contact with myocardial tissues, so either wire may be myocardial tissues, so either wire may be use as the negative, or ground electrodeuse as the negative, or ground electrode

Bipolar LeadBipolar Lead

Unipolar Pacing SystemUnipolar Pacing System

A unipolar pacing system has A unipolar pacing system has only one electrode (the negative only one electrode (the negative electrode) making contact with electrode) making contact with the heart.the heart.

In the case of unipolar epicardial In the case of unipolar epicardial lead system, the positive can be lead system, the positive can be formed by a piece of surgical formed by a piece of surgical steel wire sewn into the steel wire sewn into the sucutaneous tissue of the chest sucutaneous tissue of the chest

Unipolar LeadUnipolar Lead

Pacing RoutesPacing Routes

Transcutaneous pacingTranscutaneous pacing

Transthoracic pacingTransthoracic pacing

Epicardial pacingEpicardial pacing

Transvenous pacingTransvenous pacing

Transvenous pacingTransvenous pacing

It involves threading an electrode It involves threading an electrode catheter through a vein into the catheter through a vein into the right atrium or right ventricle. right atrium or right ventricle. Five different veins can be used.Five different veins can be used.

Antecubital approachAntecubital approach Femoral approachFemoral approach SubclavianSubclavian Internal jugularInternal jugular External jugularExternal jugular

Pacemaker terminologyPacemaker terminology

Fixed rate (Asynchronous)Fixed rate (Asynchronous)

Delivers a pacing stimulus at a set Delivers a pacing stimulus at a set (fixed) rate regardless of the (fixed) rate regardless of the occurrence of spontaneous occurrence of spontaneous myocardial depolarization; occurs myocardial depolarization; occurs in non-sensing modes. It delivers in non-sensing modes. It delivers an electrical impulse at a present an electrical impulse at a present fixed rate to the heart and fixed rate to the heart and functions independently of cardiac functions independently of cardiac activity. activity.

Pacemaker TerminologyPacemaker Terminology

Demand (synchronous)Demand (synchronous) Delivers a pacing stimulus only when Delivers a pacing stimulus only when

the heart’s intrinsic pacemaker fails the heart’s intrinsic pacemaker fails to function at a predetermined rate; to function at a predetermined rate; the pacing stimulus is either inhibited the pacing stimulus is either inhibited or triggered by the sensing of intrinsic or triggered by the sensing of intrinsic activity. activity.

The pulse generator delivers artificial The pulse generator delivers artificial stimulus only when needed or on stimulus only when needed or on demand and therefore does not demand and therefore does not compete with patient’s rhythmcompete with patient’s rhythm

Pacemaker TerminologyPacemaker Terminology

Atrioventricular (AV) Sequential Atrioventricular (AV) Sequential (Dual(Dual

Chamber)Chamber)

Delivers a pacing stimulus to Delivers a pacing stimulus to both the atrium and ventricle in both the atrium and ventricle in physiologic sequence with physiologic sequence with sufficient AV delay to permit sufficient AV delay to permit adequate ventricular fillingadequate ventricular filling

Examples of Temporary Examples of Temporary Pacing ModesPacing Modes

Asynchronous UniversalAsynchronous Universal

AOO DDD AOO DDD

VOOVOO

DOODOO Synchronous Synchronous

AAIAAI

VVIVVI

DVIDVI

Pacemaker SettingsPacemaker Settings

RATERATE

OUTPUTOUTPUT

SENSITIVITYSENSITIVITY

RATERATE

It regulates the number of impulse that It regulates the number of impulse that can be delivered to the heart per can be delivered to the heart per minute.minute.

The rate setting depend on the The rate setting depend on the physiological needs of the patient, but physiological needs of the patient, but it is generally maintained between 60-it is generally maintained between 60-80 beats/min.80 beats/min.

If the pacemaker is operating in dual-If the pacemaker is operating in dual-chamber mode, the ventricular control chamber mode, the ventricular control rate also regulate the atrial rate. rate also regulate the atrial rate.

OUTPUTOUTPUT

It is the amount of electrical It is the amount of electrical current (measured in milliamperes current (measured in milliamperes [mA]) that is delivered to the heart [mA]) that is delivered to the heart to initiate depolarization.to initiate depolarization.

The point at which depolarization The point at which depolarization occurs is termed threshold and is occurs is termed threshold and is indicated by a myocardial indicated by a myocardial response to the pacing stimulus response to the pacing stimulus (capture) (capture)

SENSITIVITYSENSITIVITY

The sensitivity control regulates The sensitivity control regulates the ability of the pacemaker to the ability of the pacemaker to the heart’sthe heart’s

intrinsic electrical activity.intrinsic electrical activity. Sensitivity is measured in Sensitivity is measured in

millivolts (mV) and determines millivolts (mV) and determines the size of the intracardiac signal the size of the intracardiac signal that generator will recognize that generator will recognize

PACINING ARTIFACTSPACINING ARTIFACTS

All patients with temporary All patients with temporary pacemaker require continuous ECG pacemaker require continuous ECG monitoring.monitoring.

The pacing artifact is the spike that The pacing artifact is the spike that is seen on the ECG tracing as the is seen on the ECG tracing as the pacing stimulus is delivered to the pacing stimulus is delivered to the heart.heart.

A P wave is visible after the pacing A P wave is visible after the pacing artifact if atrium is being paced.artifact if atrium is being paced.

Pacing ArtifactsPacing Artifacts

Pacing artifactsPacing artifacts

Pacing ArtifactPacing Artifact

ADVERSE EFFECTSADVERSE EFFECTS

Muscle stimulationMuscle stimulation PneumothoraxPneumothorax Ectopic beats like PVC’sEctopic beats like PVC’s Ventricular perforationVentricular perforation Perforation of other organs like Perforation of other organs like LiverLiver StomachStomach DiaphragmDiaphragm

--

TroubleshootinTroubleshootingg

IN TPIIN TPI

Failure to Fire Failure to Fire

Failure of the pacemaker deliver Failure of the pacemaker deliver the pacing stimulus results in the the pacing stimulus results in the disappearance of the pacing disappearance of the pacing artifact, even though the patient’s artifact, even though the patient’s intrinsic rate is less than the set intrinsic rate is less than the set rate on the pacer. This can occur rate on the pacer. This can occur either intermittently or either intermittently or continuously and can be continuously and can be attributed to failure of the pulse attributed to failure of the pulse generator or its battery generator or its battery

Failure to fireFailure to fire


CAUSESCAUSES

Loose head hookupsLoose head hookups

Dead batteryDead battery

Malfunctioning pulse generatorMalfunctioning pulse generator


INTERVENTIONSINTERVENTIONS

Secure lead hookupsSecure lead hookups

Replace batteryReplace battery

Replace pulse generatorReplace pulse generator

Failure to CaptureFailure to Capture

If the pacing stimulus fires but If the pacing stimulus fires but fails to initiate a myocardial fails to initiate a myocardial depolarization, a pacing artifact depolarization, a pacing artifact will be present but will not be will be present but will not be followed by the expected P wave followed by the expected P wave or QRS complex, depending on or QRS complex, depending on the chamber being paced. the chamber being paced.


CAUSESCAUSES

Pacemaker output too lowPacemaker output too low

Catheter dislodgedCatheter dislodged

Loose connectionsLoose connections


INTEREVENTIONSINTEREVENTIONS

Increase pacemaker outputIncrease pacemaker output

Reposition catheterReposition catheter

Secure all connectionsSecure all connections

Failure to SenseFailure to Sense

UNDERSENSINGUNDERSENSING In it pacemaker fires at wrong In it pacemaker fires at wrong

times or for the wrong reasons times or for the wrong reasons (help being given when none is (help being given when none is needed)needed)

OVERSENSINGOVERSENSING In it pacemaker fires incorrectly In it pacemaker fires incorrectly

senses depolarization and refuses senses depolarization and refuses to fire when it should (won’t pace to fire when it should (won’t pace when the patient actually needs it)when the patient actually needs it)

Failure to SenseFailure to Sense

Failure to senseFailure to sense

CAUSESCAUSES Electrolyte imbalanceElectrolyte imbalance Disconnection or dislodgement ofDisconnection or dislodgement of

leadlead Edema or fibrosis at the tip of Edema or fibrosis at the tip of

electrodeelectrode Drug interactionDrug interaction Drug batteryDrug battery

Failure to senseFailure to sense

INTERVENTIONINTERVENTION Correct the sensitivity settingCorrect the sensitivity setting

Replace batteryReplace battery

Secure all connectionsSecure all connections

Correct the underlying causeCorrect the underlying cause

Medical ManagementMedical Management

The physician determines the The physician determines the pacing route based on the pacing route based on the patient’s clinical situation. patient’s clinical situation. Generally transcutaneous pacing Generally transcutaneous pacing is used in emergent situations is used in emergent situations until a transvenous lead can be until a transvenous lead can be secured. secured.

Medical ManagementMedical Management

If the patient is undergoing heart If the patient is undergoing heart surgery, epicardial leads may be surgery, epicardial leads may be electively placed at the end of electively placed at the end of the operation. The physician the operation. The physician places the transvenous or places the transvenous or epicardial pacing lead(s), epicardial pacing lead(s), repositioning as needed to obtain repositioning as needed to obtain adequate pacing and sensing adequate pacing and sensing thresholds. thresholds.

Nursing ManagementNursing Management

Four primary areas:Four primary areas:Assessment and prevention of Assessment and prevention of

pacemaker malfunction, pacemaker malfunction, Protection against micro shock, Protection against micro shock, Surveillance for complications Surveillance for complications

such as infection such as infection Patient education. Patient education.

Prevention of Pacemaker Prevention of Pacemaker MalfunctionMalfunction

Continuous ECG monitoring is essential Continuous ECG monitoring is essential to facilitate prompt recognition and to facilitate prompt recognition and appropriate intervention for pacemaker appropriate intervention for pacemaker malfunction. malfunction.

The temporary pacing lead and bridging The temporary pacing lead and bridging cable must be properly secured to the cable must be properly secured to the body with tape to prevent the accidental body with tape to prevent the accidental displacement of the electrode, which can displacement of the electrode, which can result in failure to pace or sense. result in failure to pace or sense.

The external pulse generator can be The external pulse generator can be secured to the patient’s waist with a strap secured to the patient’s waist with a strap


For the patient on a regimen of bed For the patient on a regimen of bed rest, the pulse generator can be rest, the pulse generator can be suspended with twill tape from an suspended with twill tape from an intravenous (IV) pole mounted intravenous (IV) pole mounted overhead on the ceiling.overhead on the ceiling.

This not only will prevent tension on This not only will prevent tension on the lead while the patient is moved the lead while the patient is moved (given adequate length of bridging (given adequate length of bridging cable) but will also alleviate the cable) but will also alleviate the possibility of accidental dropping of possibility of accidental dropping of the pulse generator.the pulse generator.


The nurse inspects for:The nurse inspects for: loose connections between the lead(s) loose connections between the lead(s)

and pulse generator on a regular basis. and pulse generator on a regular basis. Replacement batteries and pulse Replacement batteries and pulse

generator must always be available on generator must always be available on the unit. the unit.

The battery has an anticipated lifespan The battery has an anticipated lifespan of 1 month, it probably is sound practice of 1 month, it probably is sound practice to change the battery if the pacemaker to change the battery if the pacemaker has been operating continually for has been operating continually for several days.several days.


Pulse generators (new Pulse generators (new generation) provide a low-generation) provide a low-battery signal 24 hours before battery signal 24 hours before complete loss of battery function complete loss of battery function to prevent inadvertent to prevent inadvertent interruptions in pacing. The pulse interruptions in pacing. The pulse generator must always be generator must always be labeled with the date that the labeled with the date that the battery was replaced. battery was replaced.

Micro-shock Micro-shock ProtectionProtection

It is important to be aware of all It is important to be aware of all sources of EMI within the critical sources of EMI within the critical care environment that could care environment that could interfere with the pacemaker’s interfere with the pacemaker’s function. Sources of EMI in the function. Sources of EMI in the clinical area include electrocautery, clinical area include electrocautery, defibrillation current, radiation defibrillation current, radiation therapy, magnetic resonance therapy, magnetic resonance imaging devices, and imaging devices, and transcutaneous electrical nerve transcutaneous electrical nerve stimulation (TENS) units. stimulation (TENS) units.

Micro-shock Micro-shock ProtectionProtection

In most cases, if EMI is suspected of In most cases, if EMI is suspected of precipitating pacemaker malfunction, precipitating pacemaker malfunction, converting to asynchronous mode converting to asynchronous mode (fixed rate) will maintain pacing until (fixed rate) will maintain pacing until the cause of the EMI is removed.the cause of the EMI is removed.

The pacing electrode provides a The pacing electrode provides a direct, low resistance path to the direct, low resistance path to the heart, the nurse takes special care heart, the nurse takes special care while handling the external while handling the external components of the pacing system to components of the pacing system to avoid conducting stray electrical avoid conducting stray electrical current from other equipment.current from other equipment.

InfectionInfection

• Infection at the lead site is a rare Infection at the lead site is a rare but serious complication but serious complication associated with temporary associated with temporary pacemakers. pacemakers.

• The (sites) is carefully inspected for The (sites) is carefully inspected for purulent drainage, erythema, and purulent drainage, erythema, and edema, and the patient is observed edema, and the patient is observed for the signs of systemic infection. for the signs of systemic infection.

InfectionInfection

Site care is performed according Site care is performed according to institution’s protocol. Although to institution’s protocol. Although most infections remain localized, most infections remain localized, endocarditis can occur in patients endocarditis can occur in patients with endocardial pacing leads.with endocardial pacing leads.

A less common complication A less common complication associated with transvenous associated with transvenous pacing is myocardial perforation, pacing is myocardial perforation, which can result in rhythmic which can result in rhythmic hiccoughs or cardiac tamponade. hiccoughs or cardiac tamponade.

Example of two common Example of two common programming codes:programming codes:

DDD DDD

Pace: Atrium and Ventricle Pace: Atrium and Ventricle

Sense: Atrium and Ventricle Sense: Atrium and Ventricle Response: Inhibited and TriggeredResponse: Inhibited and Triggered This is fully automatic or universal pacemaker This is fully automatic or universal pacemaker VVI VVI Pace: Ventricle Pace: Ventricle Sense: Ventricle Sense: Ventricle Response: InhibitedResponse: Inhibited Ventricular pacing, ventricular sensing, inhibited Ventricular pacing, ventricular sensing, inhibited

response to sensed QRS complexesresponse to sensed QRS complexes

EXAMPLES OF EXAMPLES OF TEMPORARY PACING TEMPORARY PACING

MODESMODES

Pacing Modes DescriptionPacing Modes Description AsynchronousAsynchronous AOO Atrial pacing, no AOO Atrial pacing, no

sensingsensing VOO Ventricular pacing,no VOO Ventricular pacing,no sensingsensing DOO Atrial and ventricularDOO Atrial and ventricular pacing, no sensing pacing, no sensing


MODESMODES

Pacing Modes DescriptionPacing Modes Description SynchronousSynchronous AAI Atrial pacing, atrial sensing, AAI Atrial pacing, atrial sensing, inhibited response to sensed P waveinhibited response to sensed P wave VVI Ventricular pacing, ventricular VVI Ventricular pacing, ventricular sensing, inhibited response to sensing, inhibited response to

sensed sensed QRS complexesQRS complexes DVI Atrial and ventricular pacing, DVI Atrial and ventricular pacing, ventricular sensing; both atrial and ventricular sensing; both atrial and ventricular pacing are inhibited if a ventricular pacing are inhibited if a spontaneous ventricular spontaneous ventricular depolarization is sensed. depolarization is sensed.


MODESMODES

Pacing Modes DescriptionPacing Modes Description UniversalUniversal DDD Both chambers are paced DDD Both chambers are paced and sensed; inhibited and sensed; inhibited response of the pacing stimuli to response of the pacing stimuli to sensed events in their respective sensed events in their respective chamber;triggered chamber;triggered response to send atrial activity response to send atrial activity to allow for rate – responsive to allow for rate – responsive ventricular pacing.ventricular pacing.

temporary pacemaker slides

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