a d v a n c e d p a c i n g

ADVANCED PACING

Understanding and Troubleshooting Pacemakers

Sherry L. Knowles, RN, CCRN, CRNI

Objectives

1. Understand the different pacemaker modes according to the NASPE/BPEG (NGB) universal code.

2. Recognize common pacemaker complications in a cardiac tracing.

3. Differentiate between failure to pace, loss of capture, under sensing and over sensing.

4. List appropriate nursing actions for common pacemaker complications.

5. Understand routine pacemaker settings and thresholds.

6. Identify the different types of pacemakers.

7. Understand and recognize pacemaker syndrome.

8. Be familiar with the proper use of a pacemaker magnet.

9. Understand routine nursing management of a patient with a pacemaker.

10. Recognize battery failure in temporary and permanent pacemaker devices.

At the end of this presentation, the view will be able to:

Pacemaker

Nursing Action

Indications for Pacing

Indications for Pacing• Symptomatic Bradycardia

• Heart Blocks– Second Degree AV Block – symptomatic

– Complete AV Block

• Sick Sinus Syndrome

• Overdrive Pacing

• Malfunctioning Pacemaker

• Support During Electrolyte or Acid-Base Disturbances

• To Improve Hemodynamics

• Support During Procedures

• Backup Support With Drug Therapy

Types of Pacing

• Temporary Pacing– Transvenous– Transcutaneous– Epicardial

• Permanent Pacing– High/Low Rate Setting– PR and AV Intervals– Rate Response Pacing– Mode Switching

• Fixed Rate• Controlled• Asynchronous

• Demand• Backup• Synchronous

• AV Sequential• Dual Chamber Pacing• Atrial & Ventricular wires

Pacemaker Types

Epicardial Pacing

Transcutaneous Pacing

Insertion Complications

• Dysrhythmias

• Perforation

• Pneumothorax

• Hematoma

• Hemorrhage

• Tamponade

• Pericardial Friction Rub

• Vein Thrombosis

• Infection

• Inadvertent Arterial Puncture

• Diaphragmatic Stimulation

Modes of Pacing

Chamber PacedO = NoneA = AtriumV = VentricleD = Dual ( A + V)

Chamber SensedO = NoneA = AtriumV = VentricleD = Dual ( A + V)

Response to SensingO = NoneT = Triggered I = InhibitedD = Dual ( T + I)

ProgrammabilityO = NoneP = Simple ProgrammableM= Multiple ProgrammableR = Rate Modulation

Pacemaker ModesAOO: Atrial pacing, no sensing, atrial fixed rate

VOO: Ventricular pacing, no sensing, ventricular fixed rate.

DOO: AV pacing, no sensing, AV fixed rate.

AAI: Atrial Pacing, atrial sensing, inhibited response to sensing. Atrial demand pacing.

VVI: Ventricular pacing, ventricular sensing, inhibited response to sensing. Ventricular demand pacing.

DDI: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is fixed.

AOO

VOO

DOO

AAI

VVI

DDI

Pacemaker ModesSSI: Single chamber pacing (atrial or ventricular), same chamber

sensing, inhibited response to sensing. A pacemaker that senses and stimulates one chamber at one rate.

AAT: Atrial pacing, atrial sensing, triggered response to sensing. Atrial demand pacing.

VVT: Ventricular pacing, ventricular pacing, triggered response to sensing. Ventricular demand pacing.

VAT: Ventricular pacing, atrial sensing, triggered response to sensing. The ventricular stimulus will fire at a set interval after sensing a spontaneous atrial depolarization. AV synchronous pacing.

VDD: A pacemaker that senses the atrium and ventricle and paces the ventricle (atrial synchronous, ventricular inhibited).

DDD: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate, tracking rate and minimum

rate are determined.

SSI

AAT

VVT

VAT

VDD

DDD

Pacemaker ModesSSIR: A pacemaker that senses and stimulates one chamber at a rate

determined by a sensor.

AAIR: A pacemaker that senses and stimulates the atrium at a rate determined by a sensor.

VVIR: A pacemaker that senses and stimulates the ventricle at a rate determined by a sensor.

DDIR: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is governed by a maximum rate, the rate determined by a sensor and the minimum rate.

DDDR: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is governed by a maximum rate, the rate determined by a sensor and the minimum rate.

SSIR

AAIR

VVIR

DDIR

DDDR

Single Chamber Pacing

• AAI– Paces and senses only the atria – Must have proper AV conduction

• VVI– Looses AV synchronicity– Used for temporary backup or with loss of

AV conduction (AFib)

Atrial Pacing

Ventricular Pacing

Loss of AV Synchrony

• Loss of atrial contribution

• Decrease in LV preload

• Decrease in stroke volume

• Decrease in cardiac output

• Decrease in cerebral perfusion

• Decrease in coronary perfusion

• Increase risk of pacemaker syndrome

Dual Chamber Pacing

• Maintains / Restores AV Synchrony

• Optimizes heart function

• Reduces pacemaker syndrome

• Useful in CHF

• Capable of mode switching

AV Pacing

Rate Response Pacing

• Uses sensor technology to provide rate modulation with exercise

• AAIR

• VVIR

• DDDR

Rate Response Sensors

• Activity Sensors– sensors that detect body movement. The

more the patient’s body is moving (so the reasoning goes) the faster the heart rate should be.

• Breathing Sensors– measures the patient’s rate of breathing.

The faster the breathing, the faster the heart rate should be.

Rate Response Pacing

Pacemaker Syndrome Often due to loss of AV Synchrony and/or

delayed conduction time

• Shortness of Breath

• Fatigue

• Cough

• Orthopnea

• Headache

• Syncope

• Vertigo

• Choking Sensation

• CHF, Pulmonary Edema

• Dizziness

• Apprehension

• Pulsations in the Neck

• Palpitations

• Chest Pain

• Near Syncope

• Jaw Pain

• Confusion

• Altered Mental Status

Troubleshooting

• Twelve Leads are Better than One.

• Choose leads that show the P wave and QRS morphology best.

• Look for the pacer spikes.

Failure To Pace

Causes of Output Failure

• Lead Fracture

• Lead Dislodgement

• Lead Disconnect

• Electromagnetic Interference

• Battery Failure

• Component Failure

• Over sensing

Nursing Actions

• Assess and Treat Patient

• Temporary Pacemaker– Make Sure Unit Is Turned On

– Check Battery and Connections

– Check Rate, Increase Rate As Needed

– Check mA, Increase Output As Needed

– Decrease Sensitivity (toward asynchronous or 20mV)

• Prepare For Transcutaneous Pacing

• Notify MD As Necessary

Failure To Capture

Causes of Loss of Capture

• Lead Dislodgement• Lead Insulation Defect• Battery Failure• Exit Block• Elevated Pacing Thresholds• Acute MI• Electrolyte Imbalance• Medications• Metabolic Disorders• Defibrillation• Long QT Syndrome

Loss of Capture

• Causes:– Catheter Dislodgement

– Catheter Fracture

– Unstable Connection

– Local Myocardial Necrosis/Fibrosis

– Local Myocardial Inflammation

Loss of Capture

• Causes:– Drug Effects

– Metabolic Effects

– Cautery (DC Cardioversion, Ablation)

– Lead Conductor or Insulation Failure

– Generator Malfunction

Nursing Actions






– Decrease Sensitivity (toward asynchronous or 20mV)



Pacemaker Sensitivity

• Low Sensitivity

– Towards Asynchronous

– Toward Higher mV (20mV)

– Decreases pacemaker sensing ability

• High Sensitivity

– Maximal Sensitivity

– Toward Lower mV (1mV)

– Increases pacemaker sensing ability

Failure To Sense

Nursing Actions




– Increase Sensitivity (toward synchronous or 1mV)





Pacemaker Interference

• Electromagnetic Interference (EMI)– Electromagnetic fields– Defibrillation– Electrocautery – Ablation – Lithrotripsy– Magnetic Resonance imaging (MRI)– High dose radiotherapy– Cellular telephones – TENS

• Twiddler’s Syndrome

Fusion Beats

Pacemaker Magnet

• A pacemaker magnet placed over a pacemaker generator typically eliminates sensing and returns the pacemaker to an asynchronous pacing mode (AOO, VOO or DOO).

• When using a pacemaker magnet, the rhythm changes to a controlled paced rhythm.

• Use caution when removing a pacemaker magnet because it can cause a reentry tachycardia. The last asynchronous beat is conducted through the AV node to the atrium. In this case, treat this dysrhythmia by reapplying the magnet.

Pacemaker Magnet Tracing

Transvenous Pacing

• Transvenous Pacing

– Start with new battery

– Secure leads and connections

– Set mA to 5 and adjust for capture

– Keep mA 2-3 times the threshold

Transvenous Threshold

• Transvenous Threshold– Gradually decrease mA from 5 (to 0) until

1:1 capture is lost. Then increase mA until 1:1 capture is reestablished.

– Set the mA 2-3 times the threshold.

– Check threshold qd and prn, unless directed otherwise by physician.

Transcutaneous Pacing

• Transcutaneous Pacing

– Keep pads off pacemaker/ICD devices

– Set mA to 40 and adjust for capture

– Remove paste from chest wall

– Avoid arching

– Keep mA 2 X threshold

Transcutaneous Threshold

• Transcutaneous Threshold– Gradually decrease mA from to 40 until 1:1

capture is lost. Then increase mA until 1:1 capture is reestablished.

– Set the mA 2 times the threshold.


Epicardial Pacing

• Epicardial Pacing

– Start with new battery

– Secure leads and connections

– Set mA to 3-5 and adjust for capture

– Keep mA 3 X threshold

Epicardial Threshold

• Epicardial Threshold– Gradually decrease mA from to 5 until 1:1

capture is lost. Then increase mA until 1:1 capture is reestablished.

– Set the mA 3 times the threshold.


Pacemaker Sensitivity

• Low Sensitivity

– Towards Asynchronous

– Toward Higher mV (20mV)

– Decreases pacemaker sensing ability

• High Sensitivity

– Maximal Sensitivity

– Toward Lower mV (1mV)

– Increases pacemaker sensing ability

Sensitivity Threshold

• Sensitivity Threshold– Set rate just below patient’s intrinsic rate,

the pacemaker should stop pacing and the sensor light should start flashing.

– Gradually decrease sensitivity until the pacemaker begins to fire. This is the sensitivity threshold.

– Set sensitivity to 2-3 times the sensitivity threshold.

Other Pacemaker Settings

• High/Low Rate– Sets the highest and lowest rates that the

pacemaker can pace.

• AV Interval Control – Set between 150-250 msec to preserve AV

synchrony.

• Refractory Periods – Sets a period of msec in which the pacemaker

will not respond after a sensed or paced beat.

Special Considerations

• Not necessary to disconnect temporary pacemaker during cardioversion or defibrillation

• Changes in pacing threshold may occur with electrolyte imbalance, myocardial ischemia, anemia, CHF, hypoxia, or a change in drug therapy

• Pacing threshold increases over time

Nursing Management• Continuous Cardiac Monitoring

– Watch for pacemaker complications– Always evaluate cardiac tracings

• Electrical Safety Measures– Use rubber gloves when handling external pacemaker

components– Regularly inspect all connections– Replace batteries as needed ( have spares available)– Avoid EMI sources

• Monitor Thresholds• Monitor All Imbalances

• Temperature, Acid-Base, Electrolytes

• Monitor Medication Effects• Watch For Pacemaker Syndrome

Nursing Assessment

• Assess the Patient– Vital Signs

– Cardiac Rhythm (always run strips)

– Patient Complaints

• Assess the Pacemaker– Maintain Electrical Safety

– Inspect and Secure Connections

– Assess the Effectiveness of the Pacemaker

– Check Thresholds

– Change Battery As Needed (keep spares available)

Pacemaker Evaluation

• What is the rhythm?

• Is the pacemaker functioning properly?

• What is the immediate nursing action?

Pacer Rhythm Evaluation What is the pacing Mode?

What is the underlying rhythm?

Is the pacer firing appropriately?

Is the capture appropriate?

Is the sensing appropriate?

What is the low rate limit?

What is the high rate limit?

What is the AV delay?

Nursing Management• Continuous Cardiac Monitoring

– Watch for pacemaker complications– Always evaluate cardiac tracings

• Electrical Safety Measures– Use rubber gloves when handling external pacemaker

components– Regularly inspect all connections– Replace batteries as needed ( have spares available)– Avoid EMI sources

• Monitor Thresholds• Monitor All Imbalances

• Temperature, Acid-Base, Electrolytes

• Monitor Medication Effects• Watch For Pacemaker Syndrome

PRACTICE

AAI

AAI: A pacemaker that stimulates and senses the atrium at one rate

VVI

VVI: A pacemaker that stimulates and senses the ventricle at one rate

DDI

DDI: A pacemaker that senses and stimulates both atrium and ventricle. The stimulation rate is fixed.

DDD or VVI?

What’s the Mode?

References• Guidelines for Pacemakers and Defibrillators Updated. Journal Watch General Medicine

1998: 2-2.

• Wood, D.A., Fox, K.F., Gibbs, S.R. (2001). Rapid cardiology--for chest pain, breathlessness and palpitations. QJ Med 94: 177-178.

• HAMMILL, S. C., HUBMAYR, R. D. (2000). The Rapidly Changing Management of Cardiac Arrhythmias. Am J Respir Crit Care Med 161: 1070-1073.

• Bauersfeld, U., Nowak, B., Molinari, L., Malm, T., Kampmann, C., Schonbeck, M. H., Schuller, H. (1999). Low-energy epicardial pacing in children: the benefit of autocapture. Ann. Thorac. Surg. 68: 1380-1383.

• KURBAAN, A S, SUTTON, R (1999). Pacing for vasovagal syncope. Heart 82: 649-650

• Braunwall, e. (1992) Heart Disease : a textbook of cardiovascular disease, 4 th edition, WB Saunders

• American Radio Relay League, Inc., Technical Information Service, 225 Main St., Newington, CT 06111 (860) 594-0214.

• Thelan, Lynne A., Davie, Joseph K., Urden, Linda D., Lough, Mary E. (1994) Critical Care Nursing: Diagnosis and Management. Second Edition. Pg 313-322.

• Graver, K (1998) A Practical Guide to EKG Interpretation, 2nd edition

• On-line: http://www.emedicine.com/emerg/topic699.htm

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