Pacemaker complication: Difference between revisions

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==Nomenclature==
==Background==
===Nomenclature===
[[File:paced.gif|thumb|Paced rhythm with characteristic wide LBBB and pacer spikes]]
[[File:paced.gif|thumb|Paced rhythm with characteristic wide LBBB and pacer spikes]]
[[File:xray-pacemaker.jpg|thumb|PA Xray with pacemaker]]
[[File:xray-pacemaker.jpg|thumb|PA Xray with pacemaker]]
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==Indications==
===Indications===
#Sinus Node Dysfunction-sinus bradycardia/arrest, sinoatrial block, chronotropic incompetence, a-fib.  
*Sinus Node Dysfunction-sinus bradycardia/arrest, sinoatrial block, chronotropic incompetence, a-fib.  
#Acquired AV block- 3rd degree block and 2nd degree type II
*Acquired AV block- 3rd degree block and 2nd degree type II
#Chronic Bifascicular or Trifascicular block
*Chronic Bifascicular or Trifascicular block
#After Acute MI-high mortality with persistent AV block post MI
*After Acute MI-high mortality with persistent AV block post MI
#Cardiac Resynchronization Therapy- Conduction delay (>150msec w/ mortality benefit) in chronic systolic heart failure further decreases EF, increases remodeling and increased MR.
*Cardiac Resynchronization Therapy- Conduction delay (>150msec with mortality benefit) in chronic systolic heart failure further decreases EF, increases remodeling and increased MR.
#Neurocardiogenic Syncope and Carotid Sinus Syndrome
*Neurocardiogenic Syncope and Carotid Sinus Syndrome


===Methods to Identify Manufacturer===
*Patient most often has a pocket card indicating manufacturer
*Magnet types are specific to each model so use magnets to deactivate pulse generator
*Manufactuer Hotline has patient database
**Medtronic Inc. (1-800-328-2518)
**St. Jude Medical Inc. (1-800-722-3774)
*Manufactuer code on pulse generator is visible on Chest Xray


==Expected ECG Patterns==
===Electromagnetic Interference===
#Absence of pacer artifact indicates intrinsic depolarization
*Nonmedical
#Pacing artifacts preceding depolarizations indicate successful pacing and capture
**Cell phones: do not interact with device
#Leads in RV apex produce LBBB pattern with appropriate discordance
**Airport security: may trigger alarm, no alteration of activity
#New RBBB pattern may indicate lead in LV
*Medical Sources
#Simulataneous depol of ventricles produces dominant R wave in V1
**[[MRI contraindications|MRI]]: mostly safe, consult cards on device specific recs
**Cardioversion: Use AP pads >8cm from device to minimize adverse effects


==Methods to Identify Manufacturer==
==Differential Diagnosis==
#Patient most often has a pocket card indicating manufacturer
===Pacemaker Malfunction===
#Magnet types are specific to each model so use magnets to deactivate pulse generator
====Problems with pocket====
#Manufactuer Hotline has patient database
*Infection
##Medtronic Inc. (1-800-328-2518)
**Most commonly Staphylococcus aureus or S. epidermidis
##St. Jude Medical Inc. (1-800-722-3774)
**2% local wound infection; 1% sepsis/bacteremia
#Manufactuer code on pulse generator is visible on Chest Xray
*Hematoma
**Typically occurs shortly after placement


==Plain Film Findings==
====Problems with leads====
#Obtain PA/Lateral Films to confirm pulse generator, manufacturer, lead placement/number/integrity
*Lead separation
#R atrial lead J shaped(tip medially on AP) entering right atrial appendage
*Lead dislodgment may cause thrombosis or myocardial rupture
#RV leads point downward with tip between left spine and cardiac apex--lateral XR shows inferior and anterior
*Lead infection can cause severe sepsis
#Coronary sinus lead- courses posteriorly on lateral XR
*Leads can cause tricuspid regurg, diagnosis with TTE
#Extra leads may be appropriately abandoned and capped
*Lead coiling (ie: [[Twiddler's Syndrome]]) [[File:Twiddler Syndrome.png|thumb|Twiddler Syndrome after large pocket and pacemaker wires spinning on themselves]]
#ICD component appears as thickened shock coil
==Pacemaker Malfunction==
===Problems with pocket===
#Infection
##Most commonly Staphylococcus aureus or S. epidermidis
#Hematoma
##Typically occurs shortly after placement


===Problems with leads===
===Failure to Capture===
#Lead separation
*Def-delivery of pacing stimulus without depolarization
#Lead dislodgment may cause thrombosis or myocardial rupture
*Functional- myocardium in refractory state or tissue reaction around lead insensitive
#Lead infection can cause severe sepsis
*Pathologic- drugs, myocardial disease, lytes
#Leads can cause tricuspid regurg, dx w/ TTE
*Causes-lead dislodgement, fracture, perforation, insulation defect


==Failure to Capture==
===Failure to Pace===
#Def-delivery of pacing stimulus without depolarization
*Def-failure to deliver a stimulus to the heart (with or with out capture)
#Functional- myocardium in refractory state or tissue reaction around lead insensitive
*Oversensing-most common cause-retrograde P’s, T’s, skeletal muscle myopotentials,  
#Pathologic- drugs, myocardial disease, lytes
*Crosstalk- type of oversensing-vent lead senses atrial pacing stim, and ventilator output inhibited
#Causes-lead dislodgement, fracture, perforation, insulation defect


==Failure to Pace==
===Failure to Sense===
#Def-failure to deliver a stimulus to the heart (w/ or w/o capture)
*Signal sensed when myocardial depol sent up leads and into pacemaker, if voltage exceeds threshold, pacing inhibited(appropriately)
#Oversensing-most common cause-retrograde P’s, T’s, skeletal muscle myopotentials,  
*Most commonly break in lead/insulation, battery
#Crosstalk- type of oversensing-vent lead senses atrial pacing stim, and vent output inhibited
*Voltages of patient's intrinsic QRS complex is too low to be detected
*New intrinsic arrhythmia, AMI, electrolyte abnormalities, lead separation, battery depletion


==Failure to Sense==
===Runaway Pacing===
#Signal sensed when myocardial depol sent up leads and into pacemaker, if voltage exceeds threshold, pacing inhibited(appropriately)
*Physiologic electrical activity (T waves, muscle potentials)
#Most commonly break in lead/insulation, battery
*External electromagnetic interference
#Voltages of patient's intrinsic QRS complex is too low to be detected
*Signals generated by interaction of different portions of the pacing system
#New intrinsic arrhythmia, AMI, electrolyte abnormalities, lead separation, battery depletion
*Potentially life-threatening as it can cause V-Fib or (paradoxically) bradycardia due to failure to capture


===Runaway Pacing===
===Pacemaker Mediated [[Tachycardia]]===
#Physiologic electrical activity (T waves, muscle potentials)
*Also known as Endless Loop Tachycardia
#External electromagnetic interference
*Formation of a re-entrant circuit causing inappropriate tachycardia
#Signals generated by interaction of different portions of the pacing system
*Tachycardia does not exceed programmed upper limit rate on pacemaker
 
==Evaluation==
===Work-Up===
*BMP and Mg
*[[CXR]]
*[[ECG]]
*[[Troponin]]
*Interrogation
 
===Expected ECG Patterns===
*Absence of pacer artifact indicates intrinsic depolarization
*Pacing artifacts preceding depolarizations indicate successful pacing and capture
*Leads in RV apex produce LBBB pattern with appropriate discordance
*New RBBB pattern may indicate lead in LV
*Simultaneous depol of ventricles produces dominant R wave in V1


==Work-Up==
===Plain Film Findings===
#CXR
*Obtain PA/Lateral Films to confirm pulse generator, manufacturer, lead placement/number/integrity
#ECG
*R atrial lead J shaped(tip medially on AP) entering right atrial appendage
#Troponin
*RV leads point downward with tip between left spine and cardiac apex--lateral XR shows inferior and anterior
#Interrogation
*Coronary sinus lead- courses posteriorly on lateral XR
*Extra leads may be appropriately abandoned and capped
*ICD component appears as thickened shock coil


==Management==
==Management==
#Pacemaker Mediated Tachycardia- dual chamber devices-PAC or PVC trigger with pacemaker in loop. Break with adenosine or magnet.<ref>EB Medicine- Sept 2014- Managing Pacemaker-Related Complications and Malfunctions in the Emergency Department </ref>
*Pacemaker Mediated Tachycardia
**Break with [[adenosine]] or magnet.<ref>EB Medicine- Sept 2014- Managing Pacemaker-Related Complications and Malfunctions in the Emergency Department </ref>
**Consider chest wall stimulation techniques<ref>Barold SS, Falkoff MD, Ong LS, Heinle RA. Pacemaker endless loop tachycardia: termination by simple techniques other than magnet application. Am J Med. 1988;85(6):817-22.</ref> - transcutaneous pacing, isometric muscular exercise, precordial thump
*Use magnet to convert pacemaker to asynchronous mode if oversensing or runaway pacing
*Use magnet to convert pacemaker to asynchronous mode if oversensing or runaway pacing


==Electromagnetic Interference==
==Disposition==
#Nonmedical-
*Infection - admission with [[MRSA]] coverage antibiotics, consult to cardiology, with likely replacement of pacemaker after 4-6 weeks of IV antibiotics
##Cell phones- do not interact w/ device
 
##Airport security-may trigger alarm, no alteration of activity
==See Also==
#Medical Sources
*[[Medical device complications]]
##MRI—mostly safe, consult cards on device specific recs
##Cardioversion- Use AP pads >8cm from device to minimize adverse effects


==Sources==
==References==
<references/>
<references/>
[[Category:Cards]]
[[Category:Cardiology]]
[[Category:Surgery]]

Revision as of 16:03, 25 September 2019

Background

Nomenclature

Paced rhythm with characteristic wide LBBB and pacer spikes
PA Xray with pacemaker
Atrial Sensed Ventricular Paced ECG
Pacer type based on Xray
I II III IV V
Generic code for antibradycardia pacing[1]
Chamber(s) paced Chamber(s) sensed Response to sensing Rate modulation Multisite pacing
O = None O = None O = None O = None O = None
A = Atrium A = Atrium T = Triggered R = Rate modulation A = Atrium
V = Ventricle V = Ventricle I = Inhibited V = Ventricle
D = Dual (A+V) D = Dual (A+V) D = Dual (T+I) D = Dual (A+V)

Indications

  • Sinus Node Dysfunction-sinus bradycardia/arrest, sinoatrial block, chronotropic incompetence, a-fib.
  • Acquired AV block- 3rd degree block and 2nd degree type II
  • Chronic Bifascicular or Trifascicular block
  • After Acute MI-high mortality with persistent AV block post MI
  • Cardiac Resynchronization Therapy- Conduction delay (>150msec with mortality benefit) in chronic systolic heart failure further decreases EF, increases remodeling and increased MR.
  • Neurocardiogenic Syncope and Carotid Sinus Syndrome

Methods to Identify Manufacturer

  • Patient most often has a pocket card indicating manufacturer
  • Magnet types are specific to each model so use magnets to deactivate pulse generator
  • Manufactuer Hotline has patient database
    • Medtronic Inc. (1-800-328-2518)
    • St. Jude Medical Inc. (1-800-722-3774)
  • Manufactuer code on pulse generator is visible on Chest Xray

Electromagnetic Interference

  • Nonmedical
    • Cell phones: do not interact with device
    • Airport security: may trigger alarm, no alteration of activity
  • Medical Sources
    • MRI: mostly safe, consult cards on device specific recs
    • Cardioversion: Use AP pads >8cm from device to minimize adverse effects

Differential Diagnosis

Pacemaker Malfunction

Problems with pocket

  • Infection
    • Most commonly Staphylococcus aureus or S. epidermidis
    • 2% local wound infection; 1% sepsis/bacteremia
  • Hematoma
    • Typically occurs shortly after placement

Problems with leads

  • Lead separation
  • Lead dislodgment may cause thrombosis or myocardial rupture
  • Lead infection can cause severe sepsis
  • Leads can cause tricuspid regurg, diagnosis with TTE
  • Lead coiling (ie: Twiddler's Syndrome)
    Twiddler Syndrome after large pocket and pacemaker wires spinning on themselves

Failure to Capture

  • Def-delivery of pacing stimulus without depolarization
  • Functional- myocardium in refractory state or tissue reaction around lead insensitive
  • Pathologic- drugs, myocardial disease, lytes
  • Causes-lead dislodgement, fracture, perforation, insulation defect

Failure to Pace

  • Def-failure to deliver a stimulus to the heart (with or with out capture)
  • Oversensing-most common cause-retrograde P’s, T’s, skeletal muscle myopotentials,
  • Crosstalk- type of oversensing-vent lead senses atrial pacing stim, and ventilator output inhibited

Failure to Sense

  • Signal sensed when myocardial depol sent up leads and into pacemaker, if voltage exceeds threshold, pacing inhibited(appropriately)
  • Most commonly break in lead/insulation, battery
  • Voltages of patient's intrinsic QRS complex is too low to be detected
  • New intrinsic arrhythmia, AMI, electrolyte abnormalities, lead separation, battery depletion

Runaway Pacing

  • Physiologic electrical activity (T waves, muscle potentials)
  • External electromagnetic interference
  • Signals generated by interaction of different portions of the pacing system
  • Potentially life-threatening as it can cause V-Fib or (paradoxically) bradycardia due to failure to capture

Pacemaker Mediated Tachycardia

  • Also known as Endless Loop Tachycardia
  • Formation of a re-entrant circuit causing inappropriate tachycardia
  • Tachycardia does not exceed programmed upper limit rate on pacemaker

Evaluation

Work-Up

Expected ECG Patterns

  • Absence of pacer artifact indicates intrinsic depolarization
  • Pacing artifacts preceding depolarizations indicate successful pacing and capture
  • Leads in RV apex produce LBBB pattern with appropriate discordance
  • New RBBB pattern may indicate lead in LV
  • Simultaneous depol of ventricles produces dominant R wave in V1

Plain Film Findings

  • Obtain PA/Lateral Films to confirm pulse generator, manufacturer, lead placement/number/integrity
  • R atrial lead J shaped(tip medially on AP) entering right atrial appendage
  • RV leads point downward with tip between left spine and cardiac apex--lateral XR shows inferior and anterior
  • Coronary sinus lead- courses posteriorly on lateral XR
  • Extra leads may be appropriately abandoned and capped
  • ICD component appears as thickened shock coil

Management

  • Pacemaker Mediated Tachycardia
    • Break with adenosine or magnet.[2]
    • Consider chest wall stimulation techniques[3] - transcutaneous pacing, isometric muscular exercise, precordial thump
  • Use magnet to convert pacemaker to asynchronous mode if oversensing or runaway pacing

Disposition

  • Infection - admission with MRSA coverage antibiotics, consult to cardiology, with likely replacement of pacemaker after 4-6 weeks of IV antibiotics

See Also

References

  1. Bernstein AD. et al. The revised NASPE/BPEG generic code for antibradycardia, adaptive-rate, and multisite pacing. North American Society of Pacing and Electrophysiology/British Pacing and Electrophysiology Group. Pacing Clin Electrophysiol 2002 Feb; 25(2) 260-4. lmid:11916002
  2. EB Medicine- Sept 2014- Managing Pacemaker-Related Complications and Malfunctions in the Emergency Department
  3. Barold SS, Falkoff MD, Ong LS, Heinle RA. Pacemaker endless loop tachycardia: termination by simple techniques other than magnet application. Am J Med. 1988;85(6):817-22.