Defibrillation & Cardioversion

Definition of CardioversionDefinition of Cardioversion

Cardioversion is a method to restoreCardioversion is a method to restore a rapid heart beat back to normala rapid heart beat back to normal. .

Cardioversion is used inCardioversion is used in persons who have heart rhythmpersons who have heart rhythm problems (arrhythmias), which canproblems (arrhythmias), which can cause the heart to beat too fastcause the heart to beat too fast..

Most elective or non-emergency Most elective or non-emergency Cardioversions are performedCardioversions are performed: :

• To treat atrial fibrillation or atrial flutter to To treat atrial fibrillation or atrial flutter to regain heart rhythm. regain heart rhythm.

• To treat disturbances originating in the To treat disturbances originating in the upper upper

Chambers (atria) of the heartChambers (atria) of the heart..

CardioversionCardioversion

CardioversionCardioversion

Cardioversion is used in emergencyCardioversion is used in emergency situations to correct a rapid abnormalsituations to correct a rapid abnormal rhythm associated with faintnessrhythm associated with faintness , ,low blood pressure, chest painlow blood pressure, chest pain , ,

difficulty breathing, or loss ofdifficulty breathing, or loss of consciousnessconsciousness..

Types Of CardioversionTypes Of Cardioversion

Cardioversion can be Cardioversion can be "chemical"chemical" or" or ""electricalelectrical."."

• Chemical cardioversion: Chemical cardioversion: refers to the refers to the use of antiarrhythmia medications use of antiarrhythmia medications

to restore the heart's normal rhythm. to restore the heart's normal rhythm.

Electrical cardioversionElectrical cardioversion : (also known : (also known as " direct-current" or DC cardioversion); as " direct-current" or DC cardioversion); is a procedure whereby a synchronized is a procedure whereby a synchronized electrical shock is delivered through the chest electrical shock is delivered through the chest wall to the heart through special electrodes wall to the heart through special electrodes

or paddles that are applied to the skinor paddles that are applied to the skin of the chest and backof the chest and back..

Types Of CardioversionTypes Of Cardioversion

..

The goals of the electrical The goals of the electrical cardioversioncardioversion

• Is to disrupt the abnormal electrical circuit(s) Is to disrupt the abnormal electrical circuit(s) in the heart.in the heart.

• To restore a normal heart beatTo restore a normal heart beat . .

Pharmacologic Cardioversion Pharmacologic Cardioversion

Cardioversion can be done using drugs Cardioversion can be done using drugs that are taken by mouth or given throughthat are taken by mouth or given through an intravenous line (IV)an intravenous line (IV) . .

It can take several minutes to days for aIt can take several minutes to days for a successful cardioversionsuccessful cardioversion . .

• If pharmacological cardioversion is done inIf pharmacological cardioversion is done in a hospital, your heart rate will be regularly a hospital, your heart rate will be regularly checked. checked.

• Cardioversion using drugs can be done Cardioversion using drugs can be done outside the hospital, but this requires close outside the hospital, but this requires close follow-up with a cardiologist.follow-up with a cardiologist.

Pharmacologic CardioversionPharmacologic Cardioversion

Pharmacologic CardioversionPharmacologic Cardioversion

Blood thining medicines may be givenBlood thining medicines may be given with electrical cardioversion to preventwith electrical cardioversion to prevent clots from moving to the heartclots from moving to the heart . .

ComplicationsComplicationsPossible complications of cardioversionPossible complications of cardioversion

are uncommon but may includeare uncommon but may include : :

• Worsening of the arrhythmias .Worsening of the arrhythmias .

• Blood clots that can cause a stroke or other organ Blood clots that can cause a stroke or other organ damage, bruising, burning or pain where the paddles damage, bruising, burning or pain where the paddles were used.were used.

• Allergic reactions from medicines used in pharmacologic Allergic reactions from medicines used in pharmacologic cardioversioncardioversion . .

EquipmentEquipment

• Defibrillator with a synchronising button.Defibrillator with a synchronising button.

• Emergency trolley with emergency drugs; Emergency trolley with emergency drugs; ( lignocaine, atropine, and adrenaline ).( lignocaine, atropine, and adrenaline ).

• Oxygen mask, intubation equipment, airway .Oxygen mask, intubation equipment, airway .

• Monitor and continuous recording facilities.Monitor and continuous recording facilities.

Preparing for a Preparing for a CardioversionCardioversion

Do not eat or drink for at least eight hours Do not eat or drink for at least eight hours prior to the procedure. prior to the procedure.

Take your regularly scheduled Take your regularly scheduled medicationsmedications the morning of the procedure the morning of the procedure unless your medical practitioner has told unless your medical practitioner has told you otherwise .you otherwise .

Bring a list of all your medications with Bring a list of all your medications with you.you.

Do not apply any lotions or ointments to Do not apply any lotions or ointments to chest or back as this may interfere with the chest or back as this may interfere with the adhesiveness of the shocking pads.adhesiveness of the shocking pads.

Do not drive yourself home after receiving Do not drive yourself home after receiving sedation anesthesia.sedation anesthesia.


Do not operate a car, heavy Do not operate a car, heavy machinery, or make any important machinery, or make any important decisions.decisions.

Stop digoxin before 48 hours prior the Stop digoxin before 48 hours prior the procedure.procedure.

Apply ointment to the area to reduce the Apply ointment to the area to reduce the discomfort.discomfort.


OutcomeOutcome

The procedure will be terminated either byThe procedure will be terminated either by a successful reversion to sinus rhythm ora successful reversion to sinus rhythm or

when the medical officer determines thatwhen the medical officer determines that cardioversion will not revert the rhythmcardioversion will not revert the rhythm..

DefibrillationDefibrillation Is a medical technique used to counter the Is a medical technique used to counter the onset of onset of ventricular fibrillationventricular fibrillation, a common , a common cause of cause of cardiac arrestcardiac arrest, and pulseless , and pulseless ventricular tachycardiaventricular tachycardia,,

In simple terms, the process uses an electric In simple terms, the process uses an electric shock to stop the heart arrhythmias, in the shock to stop the heart arrhythmias, in the hope that the heart will restart with rhythmic hope that the heart will restart with rhythmic contractionscontractions..

History Of DefibrillationHistory Of Defibrillation

Defibrillation was invented in Defibrillation was invented in 18991899 by Prevost by Prevost and Batelli, two Italian physiologists. Theyand Batelli, two Italian physiologists. They

discovered that electric shocks could convertdiscovered that electric shocks could convert ventricular fibrillation to sinus rhythm in dogsventricular fibrillation to sinus rhythm in dogs..The first case of a human life saved byThe first case of a human life saved by defibrillation was reported by Beck in defibrillation was reported by Beck in 19471947 . .

The Purpose Of The Purpose Of DefibrillationDefibrillation

Is to apply a controlled electricalIs to apply a controlled electrical shock to the heart, which leads to shock to the heart, which leads to

depolarization of the entire electricaldepolarization of the entire electrical conductive system of the heartconductive system of the heart..

Types of DefibrillatorsTypes of Defibrillators

InternalInternal DefibrillatorsDefibrillatorsThe device may be implanted directly in the The device may be implanted directly in the user of the deviceuser of the device..

So it is known as an So it is known as an Impalantable Impalantable cardioverter-defibrillator cardioverter-defibrillator or (much less or (much less frequently) an internal cardiac defibrillator frequently) an internal cardiac defibrillator

((ICDICD)) . .This type of defibrillator is designed to This type of defibrillator is designed to provide immediate defibrillation to high-risk provide immediate defibrillation to high-risk

patientspatients. .

Implantable Cardioversion Implantable Cardioversion DefibrillationDefibrillation

An implantable cardioverter-defibrillator (often An implantable cardioverter-defibrillator (often called an ICD) is a device that briefly passes an called an ICD) is a device that briefly passes an electric current through the heart. It is electric current through the heart. It is "implanted," or put in your body surgically. It "implanted," or put in your body surgically. It includes a pulse generator and one or more includes a pulse generator and one or more leads. The pulse generator constantly watches leads. The pulse generator constantly watches your heartbeat.your heartbeat.

AutomatedAutomated External defibrillator External defibrillator (AEDs)(AEDs) External defibrillators are typically used in External defibrillators are typically used in hospitals or ambulances, but are hospitals or ambulances, but are increasingly common outside the increasingly common outside the medical areasmedical areas. .

As automated external defibrillators As automated external defibrillators become safer and cheaperbecome safer and cheaper . .

Types of DefibrillatorsTypes of Defibrillators

Methods Of DefibrillationMethods Of Defibrillation

The shock is generally conducted through The shock is generally conducted through the heart by two electrodes, in the form of the heart by two electrodes, in the form of two hand-held paddles or adhesive two hand-held paddles or adhesive patches depending on the variety of the patches depending on the variety of the defibrillatordefibrillator..


• One electrode is placed on the right One electrode is placed on the right side of the front of the chest just below side of the front of the chest just below the clavicle.the clavicle.

• The other electrode is placed on the left The other electrode is placed on the left side of the chest just below the pectoral side of the chest just below the pectoral muscle of breast.muscle of breast.

http://en.wikipedia.org/wiki/Image:Defib_electrode_placement.JPG

Open-chest defibrillators also exist, which Open-chest defibrillators also exist, which have electrodes in the form of two cup-have electrodes in the form of two cup-shaped paddles that surround the sides shaped paddles that surround the sides of the heart and shock it directlyof the heart and shock it directly..

Open-chest defibrillators generally Open-chest defibrillators generally require less energy to operate due to require less energy to operate due to direct contact with the heartdirect contact with the heart. .


The number of attempts is in practice The number of attempts is in practice limited to a series of three or four limited to a series of three or four attempts at increasing energiesattempts at increasing energies..

The likelihood of restoring normal heart The likelihood of restoring normal heart rhythm is much less in successive rhythm is much less in successive attemptsattempts..


Differences Between Differences Between Cardioversion & DefibrillationCardioversion & Defibrillation One major difference between cardioversion One major difference between cardioversion and defibrillation with the timing of the delivery and defibrillation with the timing of the delivery

of electrical current .of electrical current .

Another major difference concerns the Another major difference concerns the circumstance defibrillation usually performed circumstance defibrillation usually performed as an emergency treatment .as an emergency treatment .

Cardioversion is usually, but not always a Cardioversion is usually, but not always a planned procedure . planned procedure .

ProcedureProcedure

The most well-known type of electrode is theThe most well-known type of electrode is the traditional metal paddle with an insulated traditional metal paddle with an insulated

handlehandle . . This type must be held in place on theThis type must be held in place on the

patient's skin while a shock or a series ofpatient's skin while a shock or a series of shocks is deliveredshocks is delivered . .

ProcedureProcedure

StepsSteps• Place paddles so that they do not Place paddles so that they do not

touch pts clothing or bed linens or touch pts clothing or bed linens or not near direct oxygen supply.not near direct oxygen supply.

• Ensure monitor is attached to pat.Ensure monitor is attached to pat.• Do not charge the machine untill Do not charge the machine untill

ready to shock.ready to shock.

ProcedureProcedure

• Exert 25 pound pressure on the Exert 25 pound pressure on the paddle .paddle .

• Ensure you and every body is free Ensure you and every body is free of the pat.Inspect skin for burns.of the pat.Inspect skin for burns.

• Record the delivered energy.Record the delivered energy.

TreatmentTreatmentShock may be delivered, but it is notShock may be delivered, but it is not regarded as the treatment of choiceregarded as the treatment of choice..

Antiarrhthmic medications such asAntiarrhthmic medications such as amiodarone, cordorone, lidocaineamiodarone, cordorone, lidocaine , ,

magnesium, or pronestly are given ifmagnesium, or pronestly are given if ventricular dysrhythmia persistsventricular dysrhythmia persists..

TreatmentTreatment

The probability of a successful conversion isThe probability of a successful conversion is very small according to the currentvery small according to the current

guidelines, in this situation, continued CPR inguidelines, in this situation, continued CPR in order to improve the oxygenation of the heartorder to improve the oxygenation of the heart

for a few minutes is preferred beforefor a few minutes is preferred before defibrillation is attempteddefibrillation is attempted. .

..

WarningWarning

As the nurse applies the shock this is justAs the nurse applies the shock this is just a warning to everyone around to a warning to everyone around to stay stay

away away from the patient for risk offrom the patient for risk of electrical shockelectrical shock..

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Defibrillation & Cardioversion