Cardiology in Critical Care


nursebob 07/25/10


After review and study of these pages and attendance at an approved nursing skills lab the critical care nurse should be able to:

1. Defined the dysrhythmias for which cardioversion might be required.

2. Demonstrate the emergency procedures to be followed as related to cardioversion.

3. Defined the Difference between Cardioversion Defibrillation.

4. To convert tachydysrhythmias that endangered a hemodynamic status.

5. Two prevent the development of ventricular fibrillation in the presence of unstable ventricular tachycardia with a pulse.

Defibrillation vs. Cardioversion:

The difference between defibrillation and cardioversion is that the countershock is synchronized to the QRS complex which allows the electric current to be delivered after the R wave and before the the period associated with the T wave. It is the treatment of choice if the patient has a hemodynamically unstable tachydysrhythmia. It is the primary treatment for most tachydysrhythmias. It is used for the treatment of unstable ventricular tychardia with a pulse, since this often leads to ventricular fibrillation, atrial flutter, atrial fibrillation, and most tachycardias. With cardioversion the potential exists to prevent this life-threatening dysrhythmias.

Cardioversion may either be a planned or emergent procedure. If done as an elective procedure, the patient should be sedated before cardioversion begans. Of course, the institutions policies and procedures for conscious sedation should be followed.

Properly done cardioversion will correct the patient’s dysrhythemia with minimal discomfort and maximum safety.

Specialized equipment required:



connecting media marred defibrillator pads

emergency cart and medications

emergency pacing equipment


1. The patient should be connected to monitor and a rhythm strip obtained in order to verify the type of tacky dysrhythmia the patient has. isand this arrhythmia may be mistaken for an artifact.

  • Check to make sure that the patient has pulse. Determine if he is it hemodynamically stable. Rule out hypotension, chest pain, altered mental status, shortness of breath, shock or other conditions which may be related to tachycardia.
  • 2. Conscious sedation should be used for the patient. Insure that your institution’s protocol regarding conscious sedation is followed.

    3. The patient should be connected to monitor/defibrillator according to manufacturers and institutional recommendations. Attach the monitor leads (white to right, opposite is black, red to ribs) and choose lead that gives the best R wave.

  • This will insure that Counter shock is delivered during the QRS complex.
  • 4. Engage synchronization button.

    5. Look for markers on the R wave that would indicate a synchronization mode. If necessary, adjust R wave gain control until the synchronization markers occur with each QRS complex.

    6. Select the proper energy level.

    7. Apply the conductive medium to the patient and paddles.

  • This will prevent burns from the electrical current and insure of passage of the current through the cardiac muscle mass.
  • 8. Positioned in paddles on the patient by that apply one at apex to the left of the nipple in the mid axillary line and other just below the right clavicle to the right of the sternum.

    9. Push the charge button on the defibrillator and allow it to charge.

  • Energy is not available until the defibrillator is fully charged.
  • 10. The electrocardiogram recorder should be on.

  • This will establish a visual reporting and permanent record of the patient and his response to intervention.
  • 11. Apply 25 pounds per square inch pressure to the paddles.

  • This decrease is intrathoracic resistance and improves the flow of current across axis of the heart.
  • 12. If unsuccessful, press synchronization and increase the amount of energy to be delivered.

  • If ventricular fibrillation or pulseless ventricular tachycardia develops, deactivate the synch button, and follow the procedures for defibrillation.
  • 13. To removing unwanted charge, press energy select.

    14. Document the procedure in a clinical record are cardiac arrest flowsheet.

    Post cardioversion care:

    1. generally the care for a patient tells cardioversion is the same as for the fibrillation.

    2. If it is a elective procedure, digioxin is usually withheld for 48 hours prior to cardioversion to prevent dysrhythmias after the procedure.

    3. Airway patency should be maintained and the patient state of consciousness should be evaluated.


    Reference: Advanced Cardiac Life Support, 1994 American Heart Association.

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