Anesthetic considerations for patient with pacemaker By Ahmed M. Shehata Assistant lecturer
Transcript
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By Ahmed M. Shehata Assistant lecturer
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INTRODUCTION 30,000,000 patients worldwide have been implanted
pacemakers while 3,000,000- 5,000,000 have a Implantable
Cardioverter Defibrillator (lCD). 115,000 new devices are implanted
each year in U.S.
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Temporary Pacing Transcutaneous Pacing External electrode pads
and power device Large electrodes over precordium & back at
level of heart Output: up to 140 mA Terminate: Tachy- arrhythmia
Pacing rate: up to 180 bpm Sensing facility (VVI pacing possible)
Transcutaneous Pacing External electrode pads and power device
Large electrodes over precordium & back at level of heart
Output: up to 140 mA Terminate: Tachy- arrhythmia Pacing rate: up
to 180 bpm Sensing facility (VVI pacing possible) Transvenous
Pacing Electrode placed via femoral, brachial, IJV or subclavian
vein 90% success rate in absence of fluroscopy under ECG guidance
Atrial J-shaped electrodes and balloon tipped ventricular
electrodes Externally paced generator with output up to l0mA All
pacing modes available Transvenous Pacing Electrode placed via
femoral, brachial, IJV or subclavian vein 90% success rate in
absence of fluroscopy under ECG guidance Atrial J-shaped electrodes
and balloon tipped ventricular electrodes Externally paced
generator with output up to l0mA All pacing modes available
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Temporary Pacing Indications A. Unstable bradydysrhythmias B.
Unstable tachydysrhythmias C. Third degree Atrioventricular block
Endpoint: resolution of the problem or permanent pacemaker
implantation.
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Permanent PACEMAKER Ventricular / Atrial channel transmits the
Pacing impulse to the respective lead. Power source, Circuit
Electrodes: 1.Uni /Bi polar
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Indication of Permanent Pacing A. Sinus Node Dysfunction -
Symptomatic diseases of impulse formation. Sinus bradycardia, sinus
pause or arrest, or sinoatrial block. 5O% implantation. B. Atrial
Fibrillation - Dual site atrial pacing to decrease intra-atrial
conduction time.
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Indications cont.. C. AV Block: Due to ischaemic / congenital /
degenerative / inflammatory. Block within HIS Purkinje system. 3rd
block with symptomatic bradycardia, documented asystole.
Asymptomatic 3rd block, asymptomatic Type II 2nd block,
asymptomatic Type I 2nd block. D. Chronic BBB likely to progress to
CHB.
Generic Pacemaker Codes The North American Society of Pacing
and Electrophysiology (NASPE) and British Pacing and
Electrophysiology Group (BPEG) Pacemaker codes.
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Position III: Response to Sensing I (Inhibited): The chamber is
paced unless intrinsic electrical activity is detected during the
pacing interval. T (Triggered): The pacing device will emit a pulse
only in response to sensed event. D (Dual): Provides AV synchrony.
Pacing device emits atrial pulse if no sensed atrial event takes
place, once an atrial event has occurred, the pacing device will
ensure that a ventricular event follows.
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Position IV: Programmability Vibration sensor Motion sensor
Minute ventilation sensor the sensor detects exercise, it increases
the pacing rate (termed sensor-indicated rate). As the exercise
tapers, this sensor-indicated rate returns to the programmed lower
rate.
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Position V: Multisite Pacing With 2002 revision the, fifth
column describes multisite pacing. Atrial multisite pacing might
prevent atrial fibrillation. Ventricular multisite pacing is an
acceptable means of pacing patients with dilated
cardiomyopathy.
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modes of pacing 4 modes of pacing: - Asynchronous (AOO, VOO and
DOO) Used safely in cases with NO ventricular activity.
Disadvantages: Competes with patients intrinsic rhythm &
results in induction of tachyarrythmias. Continuous pacing wastes
energy & decreases battery half-life. - Single-chamber deman
Atrial-only antibradycardia pacing. Inappropriate for chronic AF
& long ventricular pauses.
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Single Chamber Ventricular Pacing (VVI, VVT) - Ventricular-only
antibradycardia pacing. - Indicated complete heart block with
chronic atrial flutter, AF & long ventricular pauses. Dual
Chamber AV Sequential Pacing (DDD, DVI, DDI, VDD) - Preserve the
normal atrioventricular contraction sequence. - Indicated AV block,
carotid sinus syncope & sinus node disease. modes of pacing
cont..
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PACEMAKER FAILURE Pacemaker failure has three aetiologies: 1)
Failure to capture: ( the generator continues to fire but no
myocardial depolarization takes place) a. Myocardial
ischemia/infarction, b. Acid-base disturbance, c. Electrolyte
abnormalities, d. Abnormal antiarrhythmic drug levels. e. External
pacing might further inhibit pacemaker. 2) Lead failure, 3)
Generator failure.
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Pacemaker syndrome occurs in patients with ventricular
pacemakers. The awake patient may experience syncope,
breathlessness, postural hypotension, and other symptoms associated
with a low cardiac output. pacemaker is stimulating the venticles
of the heart so, activation of the heart starts in the ventricles
and then spreads upward to the atria. So, the normal activation of
the heart electrically is reversed. the atria beat against closed
valves.
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ICD (Implantable Cardioverter Defibrillator) Battery powered
device to deliver sufficient energy to terminate VT / VF. all
discharges are painful Superior to anti- arrhythmic therapy in
preventing death in ventricular tachy- arrhythmias.
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Indications for ICDs A. Ventricular Tachycardia B. Ventricular
Fibrillation C. Brugada Syndrome (RBBB, ST-segment elevation in V 1
to V 3 ) D. Arrhythmogenic RV Dysplasia E. Long Q-T Syndrome F.
Hypertrophic cardiomyopathy G. Prophylactic use in patient who has
cardiomyopathy with EF 35% & Post-MI patients with EF 30%.
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Generic Defibrillator Code NASPE/BPEG:
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Effect of Magnet Each PM/ICD is programmed to respond in a
specific manner to magnet placement. Magnet usually result in
pacemaker to switch to asynchronous mode. Magnet never turn off
pacemaker. ICD will be inhibited to deliver antitachycardia therapy
when magnet is applied. Pacemaker function of ICD is not
inhibited.
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Effect of Magnet Magnet placement is not an advisable practice
to employ in all cases. If the patient is not pacemaker dependent,
an asynchronous mode will compete with the intrinsic rhythm. Some
types of pacemakers, application of a magnetic field is a step
required to initiate reprogramming of the generator. Random
reprogramming when exposed to magnetic fields.
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Magnet application to a VVI pacemaker. Normal sinus rhythm with
normal AV conduction Magnet application Fixed rate, ventricular
pacing
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Anesthetic Considerations Preoperative Evaluation History;
special attention for CV system, AMI, arrhythmia, underlying rhythm
medical records review, review CXR, ECG Physical examination (check
for scars, palpate for device). Direct interrogation with a
programmer remains the only reliable method for evaluation; type,
dependency on pacing, programmed function. Obtain manufacturers
identification card. Get CXR if no other data available.
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Anesthetic Considerations Preoperative Evaluation cont..
Permenant pacemaker reprogramming: - Asynchronous pacing mode at a
rate greater than the patients underlying rate ICD reprogramming: -
Disabling the antitachycardia therapie function always indicated -
With pacing function Disabling the anti- tachycardia therapy +
Asynchronous pacing mode
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Single chamber pacemaker
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Dual chamber pacemaker
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Preoperative Preparation Determine whether EMI is likely to
occur during the procedure. Determine whether reprogramming pacing
function to asynchronous mode or disabling rate responsive function
is advantageous or not Suspend antitachyarrhythmia functions if
present. Anesthetic Considerations
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Preoperative Preparation cont Advise surgeon to consider use of
a bipolar electrocautery or ultrasonic (harmonic) scalpel.
Temporary pacing and defibrillation equipment should be immediately
available. Evaluate the possible effects of anesthetic techniques
and of procedure on PM function. Anesthetic Considerations
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Intraoperative Management Monitor operation of PM by: ECG.
Monitor peripheral pulse (manual pulse palpation, pulse oximeter
plethysmogram, arterial line). Because of the vasodilating effects
of potent inhaled anesthetics, pacemaker syndrome in the
anesthetized patient will be more significant than in the awake
patient Preservation of intrinsic rhythm of the patient with a
demand pacemaker is achieved by preventing bradycardia. Anesthetic
Considerations
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Intraoperative Management cont.. beta agonists have potent
inotropic, chronotropic and vasodilatory effects. This causes an
increase in myocardial oxygen requirements and a decrease in
systemic vascular resistance. Ischemia, myocardial infarction, or
dysrhythmias may result. when suxamethonium is to be used in a
patient with a permanent pacemaker, consideration should be given
to reprogramming the pacemaker to asynchronous mode before
induction of anaesthesia. Anesthetic Considerations
Manage potential PM dysfunction due to EMI. 1. Electrocautery.
Assure that electrosurgical receiving plate is positioned so that
current pathway does not pass through PM. Advise surgeons to avoid
proximity of cautery to PM or leads. Advise surgeons to use short,
intermittent, and irregular bursts at the lowest feasible energy
levels. Advise surgeons to reconsider use of bipolar electrocautery
system. 2. Radiofrequency ablation. Advise surgeons to avoid direct
contact between the ablation catheter and PM and leads. Advise
surgeons to keep radiofrequency current path as far away from PM
and leads.
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3. Lithotripsy. Advise surgeons to avoid focusing the
lithotripsy beam near pulse generator. 4. MRI. MRI is generally
contraindicated If MRI must be performed, consult with the ordering
physician, cardiologist, radiologist and PM manufacturer.
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5. Radiation therapy. Radiation therapy can be safely
performed. Surgically relocate the PM if the device will be in the
field of radiation. 6. Electroconvulsive therapy. No significant
damage if PM disabled Consult with the ordering physician,
cardiologist, PM manufacturer.
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Postoperative Management Continuously monitor HR & rhythm.
Have backup pacing & defibrillation equipment available
throughout the immediate postoperative period. Interrogate and
restore PM function in the immediate postoperative period. Restore
all antitachyarrhythmic therapies in ICDs. Assure that all other
settings of the PM are appropriate.
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References Practice Advisory for the Perioperative Management
of Patients with Cardiac Rhythm Management Devices: Pacemakers and
Implantable Cardioverter Defibrillators, ASA, Anesthesiology 103:
186198. T. V. Salukhe, D. Dob and R. Sutton, Pacemakers and
defibrillators: anaesthetic implications, Br J Anaesth; 93: 95-104.
ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac
Rhythm Abnormalities, J. Am. Coll. Cardiol.; 51; e1-e62 Kaplans
Cardiac Anesthesia. Millers Anesthesia. Stoeltings Anesthesia &
Co-existing Disease