Cardioversion

Question 1

What is cardioversion?

Answer 1

Cardioversion is the application of electrical energy to a patient
to convert a cardiac rhythm such as atrial fibrillation, atrial
flutter, or stable ventricular tachycardia to a normal rhythm. The
electrical discharge is timed to coincide with the R wave of the
QRS complex.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1269-1270.

Question 2

What is the difference between cardioversion and

defibrillation?

Answer 2

Cardioversion is typically a scheduled and planned procedure
(although it can be performed emergently as well) that uses
synchronized electrical energy to convert a patient’s cardiac
rhythm. Defibrillation is an emergent procedure that is not
synchronized to the patient’s cardiac rhythm and requires a
much larger amount of electrical energy.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1270

Question 3

How does the preoperative preparation for a
cardioversion differ from that of a patient undergoing
general anesthesia for surgery?

Answer 3

It doesn’t. The patient should undergo as thorough a
preoperative evaluation as any other patient. NPO status
should be as rigorously verified as for any other surgery
because the risk of aspiration is just as likely. If an emergent
cardioversion is necessary and the patient is to be anesthetized
for the procedure, then tracheal intubation is required.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1270.

Question 4

What energy level is used to ‘shock’ the patient back

into a normal rhythm?

Answer 4

Ideally, 50-100 Joules are used to cardiovert the patient. In the
event the rhythm does not convert, the energy level is increased
to a maximum level of 360 Joules.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1270.

Question 5

Is muscle relaxation required for cardioversion?

Answer 5

No, but if the patient is not NPO, a rapid-sequence induction
using a muscle relaxant prior to intubation may be required.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1270.

Question 6

How is an anesthetic for cardioversion generally

administered?

Answer 6

After standard anesthesia monitors are applied, the patient is
pre-oxygenated via an ambu bag or via mask using an
anesthesia machine and circuit. The patient is administered an
intravenous induction agent. Once the eyelash reflex is
abolished, positive-pressure ventilation is halted. An ‘all clear’
signal is announced by the person performing the cardioversion
and the synchronized shock is delivered. The patient is
assisted in ventilation until normal swallowing and coughing
reflexes return and the care is turned over to the recovery nurse
for postanesthesia and cardiac monitoring.
Nagelhout JJ, Plaus KL. Nurse Anesthesia. 5th ed. St. Louis,
MO: Elsevier Saunders Company; 2014: 1270.