Pacemakers and Pacemakers and Implanted Implanted

DefibrillatorsDefibrillatorsMike HarlanMike Harlan

HistoryHistory

PacemakersPacemakers– It is believed that Dr. Albert Hyman was inventor of first It is believed that Dr. Albert Hyman was inventor of first

pacemakerpacemaker– First fully functional wearable pacemaker developed in First fully functional wearable pacemaker developed in

19571957– First implanted pacemaker 1960First implanted pacemaker 1960

ICD’sICD’s– First implantable ICD developed by Michel Mirowski, first First implantable ICD developed by Michel Mirowski, first

used in a human in 1980used in a human in 1980– FDA approved use of ICD’s in 1985FDA approved use of ICD’s in 1985

Artificial PacemakersArtificial Pacemakers An internal artificial pacemaker is An internal artificial pacemaker is

a small battery-operated device a small battery-operated device that helps the heart beat in a that helps the heart beat in a regular rhythmregular rhythm

An electrode is placed next to the An electrode is placed next to the heart wall, and small electrical heart wall, and small electrical charges travel through the wire charges travel through the wire to the heart (usually the right to the heart (usually the right side), causing it to contract.side), causing it to contract.

Most modern pacemakers have a Most modern pacemakers have a sensing device that turns the sensing device that turns the pacemaker off when the natural pacemaker off when the natural heartbeat is above a certain levelheartbeat is above a certain level

Types of PacemakersTypes of Pacemakers

Fixed-rate – fires continuously at a preset Fixed-rate – fires continuously at a preset raterate

Demand – contain a sensing device, fire Demand – contain a sensing device, fire only when heart rate drops below a set only when heart rate drops below a set raterate

Dual-chambered – stimulates the atria first Dual-chambered – stimulates the atria first and then the ventricleand then the ventricle

Pacemaker IndicationsPacemaker Indications Absolute IndicationsAbsolute Indications

– Sick sinus rhythmSick sinus rhythm– Symptomatic sinus bradycardiaSymptomatic sinus bradycardia– Tachy-brady syndromeTachy-brady syndrome– Atrial Fibrillation with slow ventricular responseAtrial Fibrillation with slow ventricular response– Third Degree Heart BlockThird Degree Heart Block– Chronotropic incompetenceChronotropic incompetence– Prolonged QT syndromeProlonged QT syndrome

Relative IndicationsRelative Indications– CardiomyopathyCardiomyopathy– Severe refractory neurocardiogenic Severe refractory neurocardiogenic

syncopesyncope– Paroxysmal atrial fibrillationParoxysmal atrial fibrillation

Results of a recent study showed that pt’s Results of a recent study showed that pt’s with pacemakers had a one-year with pacemakers had a one-year recurrence rate of syncope of 19%, recurrence rate of syncope of 19%, compared to 60% of pt’s in the control compared to 60% of pt’s in the control groupgroup

Pacemaker ComplicationsPacemaker Complications

InfectionInfection ThrombophlebitisThrombophlebitis

– Blood clot causes inflammation in veinBlood clot causes inflammation in vein Pacemaker SyndromePacemaker Syndrome

– Phenomenon where a pt. feels worse after Phenomenon where a pt. feels worse after pacemaker placement and presents with pacemaker placement and presents with progressive worsening of symptoms of CHFprogressive worsening of symptoms of CHF

Failure to outputFailure to output Failure to captureFailure to capture Failure to sense correctlyFailure to sense correctly

Internal Cardiac DefibrillatorsInternal Cardiac Defibrillators ICD’s have wires connecting to one or more heart ICD’s have wires connecting to one or more heart

chamberschambers.. The wires monitor heart rhythm and The wires monitor heart rhythm and deliver shocks to the heart when abnormal rhythm deliver shocks to the heart when abnormal rhythm is sensed.is sensed.

Single chamber ICD’s – wires connect to one or Single chamber ICD’s – wires connect to one or both ventriclesboth ventricles

Dual-chamber ICD’s – wires connect to both an Dual-chamber ICD’s – wires connect to both an atrium and a ventricleatrium and a ventricle

Wires of an ICD connect to small metal box that Wires of an ICD connect to small metal box that contains a battery, pulse generator, and computercontains a battery, pulse generator, and computer

ICD’s are indicated for pt’s with hx of life-ICD’s are indicated for pt’s with hx of life-threatening ventricular tachyarrhythmias or VFthreatening ventricular tachyarrhythmias or VF

A recent study showed that pt’s that received an A recent study showed that pt’s that received an ICD had a 31% reduction in mortality rate.ICD had a 31% reduction in mortality rate.

ICD complicationsICD complications

Most common Most common problem is that they problem is that they shock when not shock when not needed. This can needed. This can damage the heart or damage the heart or trigger an irregular trigger an irregular heartbeatheartbeat

Swelling, bruising, or Swelling, bruising, or infection after infection after surgerysurgery

Treatment of pt’s with pacemakers or Treatment of pt’s with pacemakers or ICD’sICD’s

The presence of a pacemaker or ICD does not alter The presence of a pacemaker or ICD does not alter the emergency treatment of patientsthe emergency treatment of patients

Defibrillation, cardioversion, and pacing can be Defibrillation, cardioversion, and pacing can be performed on pt’s with pacemakers or ICD’sperformed on pt’s with pacemakers or ICD’s– Try to place pads a safe distance (10cm) from a Try to place pads a safe distance (10cm) from a

pacemaker or ICD if possible, but don’t delay pacemaker or ICD if possible, but don’t delay treatmenttreatment

– A magnet can be placed over the pulse generator A magnet can be placed over the pulse generator to reset the pacemaker to a predetermined rate. to reset the pacemaker to a predetermined rate. This is indicated if a pt. has a runaway pacemakerThis is indicated if a pt. has a runaway pacemaker

ReferencesReferences

Bledsoe B, Porter R, Cherry R. Bledsoe B, Porter R, Cherry R. Essentials of Essentials of Paramedic CareParamedic Care. Second Edition. Prentice Hall; . Second Edition. Prentice Hall; 20072007

http://emedicine.medscape.com/article/780825-http://emedicine.medscape.com/article/780825-printprint

http://www.nhlbi.nih.gov/health/dci/Diseases/http://www.nhlbi.nih.gov/health/dci/Diseases/icd.htmlicd.html

http://emedicine.medscape.com/article/162245-http://emedicine.medscape.com/article/162245-overviewoverview

Gregoratos G, Gregoratos G, Indications and Recommendations Indications and Recommendations for Pacemaker Therapy.for Pacemaker Therapy. American Family American Family Physician, 2005Physician, 2005