In which situation is synchronized cardioversion (cardioversion using electrical shocks synchronized with the patient's cardiac cycle) used?

From the Guidelines

Synchronized cardioversion should be performed in patients with hemodynamically unstable supraventricular tachycardia (SVT) or pre-excited atrial fibrillation (AF) when vagal maneuvers or adenosine are ineffective or not feasible. This recommendation is based on the 2015 ACC/AHA/HRS guideline for the management of adult patients with supraventricular tachycardia 1. The guideline suggests that synchronized cardioversion is highly effective in terminating SVT and pre-excited AF, and it should be considered early in the management of hemodynamically unstable patients.

Indications for Synchronized Cardioversion

• Hemodynamically unstable patients with SVT or pre-excited AF
• Patients with SVT who are stable but have not responded to pharmacological therapy
• Patients with pre-excited AF who are hemodynamically unstable

Key Considerations

• Synchronized cardioversion should be performed after adequate sedation or anesthesia
• The initial energy settings typically range from 50-100 joules for atrial fibrillation, with escalating energy as needed for subsequent shocks
• Synchronized cardioversion differs from defibrillation, which is used for pulseless ventricular tachycardia or ventricular fibrillation and delivers an unsynchronized shock, as noted in the 2010 American Heart Association guidelines for cardiopulmonary resuscitation and emergency cardiovascular care 2.

Clinical Context

In clinical practice, synchronized cardioversion is a valuable treatment option for patients with unstable tachyarrhythmias. It is essential to carefully evaluate the patient's hemodynamic status and consider the potential risks and benefits of the procedure. By following the guidelines and recommendations outlined above, healthcare providers can ensure that patients receive the most effective and safe treatment for their condition.

From the Research

Synchronized Cardioversion

Synchronized cardioversion is used in various situations, including:

• Atrial fibrillation (AF) [ 3 ]
• Atrial flutter [ 3 , 4 ]
• Atrial tachycardias [ 3 ]
• Supraventricular tachycardias in children [ 5 ]

Key Considerations

When choosing a cardioversion method, key aspects to consider include:

• Patient comorbidity profile [ 3 ]
• Antiarrhythmic drug onset of action and side effect profile [ 3 ]
• Need for a physician with experience in sedation or anaesthetics support for electrical cardioversion [ 3 ]

Cardioversion Methods

Different cardioversion methods are available, including:

• Electrical cardioversion using biphasic truncated exponential (BTE) waveforms [ 3 , 6 ]
• Pharmacological cardioversion using antiarrhythmic drugs such as quinidine, ibutilide, and propafenone [ 3 ]