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Information ⬇

Author(s): Sandeep Hothi and David Sprigings

The management of arrhythmias is described in Chapters 39, 40, 41, 42, 43, 44. Indications, contraindications and potential complications of DC cardioversion are summarized in Table 121.1. Equipment needed is given in Table 121.2.

Haemodynamic compromise with tachyarrhythmias at rates less than 130/min should prompt consideration of other causes, such as hypovolaemia, sepsis, pulmonary embolism or heart failure.

Technique in Haemodynamically Stable Patients

Preparation

  1. Attach an ECG monitor and record a 12-lead ECG. Check the arrhythmia. General aspects of the preparation of the patient before cardioversion of atrial fibrillation or flutter are summarized in Table 121.3. Contact an anaesthetist to discuss the anaesthetic management and timing of the procedure. Discuss the procedure with the patient and obtain consent.
  2. Put in a peripheral venous cannula, give supplemental oxygen via nasal cannulae or a facemask, and monitor arterial oxygen saturation by oximetry. Check the blood pressure. Check that the defibrillator, resuscitation equipment and drugs are to hand.
  3. Lay the patient down and change the ECG leads from the bedside monitor to the defibrillator. Adjust the leads until the R waves are significantly higher than the T waves and check that the synchronizing marker falls consistently on the QRS complex and not the T wave. Place self-adhesive defibrillator pads on the sternum and over the cardiac apex (check this). Elevate the bed so that the airway is easily accessible.
  4. The anaesthetist administers general anaesthesia or deep sedation.

Countershock

  1. When the patient is anaesthetized, charge the defibrillator and deliver an appropriate charge to cardiovert the arrhythmia (Table 121.4). If the first shock fails to restore a sinus rhythm, deliver a second and if needed a third shock, at higher energy. The operator should call to all staff that the defibrillator is being charged and again before delivering the shock, and should look to make sure that no one is in contact directly or indirectly with the patient before the shock is delivered.

Aftercare

  1. Record a 12-lead ECG. Consider prophylactic antiarrhythmic therapy to maintain the sinus rhythm. Write a note of the procedure in the patient's record, documenting: indications/anaesthetic technique/shocks delivered/any complications/post-procedure rhythm/plan of management.
  2. Continue heparin/warfarin/DOAC anticoagulation for at least one month (or indefinitely if indicated) after successful cardioversion of atrial fibrillation or flutter of more than 48h duration.

Considerations for specific arrhythmias and circumstances

Synchronized DCCV may not be possible (very rapid VT) or dangerous (polymorphic VT) with risk of VF. In these situations, defibrillation should be performed as there is a risk of inducing VF with synchronized DCCV.

Patients with permanent pacemakers/ICDs/CRT devices – place pads in the antero-posterior position with both at least 12cm from the generator. Use lowest indicated energy setting. Obtain a device check after DCCV.

ICD/CRT-D – cardioversion may be performed by the device using a device programmer. Avoids risk of injury to the system and of skin burns. However, consumes significant device energy.

Digoxin toxicity induced arrhythmias: digoxin toxicity is a relative contraindication to DCCV as it can exacerbate electrically induced arrhythmias. Correct hypokalaemia in all cases. Conservatively manage nodal or atrial tachycardia. SVTs: ideally defer DCCV until digoxin levels are normal and use the lowest indicated energy level. VT: consider IV lidocaine pre-shock and use the lowest indicated energy level.

Pregnancy – DCCV can be performed for the mother. Fetal heart rate monitoring is recommended.

Atrial fibrillation with potentially reversible causes, such as infection, pericarditis, post-operative, pulmonary embolism or hyperthyroidism may not benefit from acute DCCV whilst the exacerbating factor is still present, unless there is haemodynamic compromise, due to the increased chance of recurrence or failure.

Further Reading ⬆

Page RL, Joglar JA, Caldwell MA, et al. (2016) 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia: a report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society. J Am Coll Cardiol 67, e27–115.

The Task Force for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death of the European Society of Cardiology (ESC) (2015) 2015 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death. Eur Heart J 36, 2793–2867. DOI: 10.1093/eurheartj/ehv316

The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC) (2016). 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. European Heart Journal . Published online 27 August 2016. Add citation at proof stage.