What are the indications for electrical cardioversion?

From the Guidelines

Electrical cardioversion is recommended for patients with atrial fibrillation (AF) and acute or worsening hemodynamic instability to improve immediate patient outcomes. This is based on the most recent and highest quality study, the 2024 ESC guidelines for the management of atrial fibrillation 1.

Indications for Electrical Cardioversion

The indications for electrical cardioversion include:

• Hemodynamically unstable AF or atrial flutter
• AF with rapid ventricular response causing angina, heart failure, or syncope
• Persistent AF or atrial flutter (>48 hours) after anticoagulation
• Ventricular tachycardia with a pulse
• Supraventricular tachycardias unresponsive to vagal maneuvers and medications

Pre-Cardioversion Anticoagulation

Before performing cardioversion, it is essential to ensure proper anticoagulation for AF lasting >48 hours or of unknown duration. This can be achieved with heparin or low-molecular-weight heparin, and consideration should be given to transesophageal echocardiography to rule out left atrial thrombus, as recommended by the 2024 ESC guidelines 1 and supported by other studies such as the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation 1.

Procedure

For the procedure:

1. Sedate the patient (e.g., midazolam 1-2 mg IV or propofol 0.5-1 mg/kg IV)
2. Apply paddles or adhesive pads in anterolateral or anteroposterior position
3. Use biphasic shock starting at 120-200 J, or monophasic shock at 360 J
4. Increase energy for subsequent shocks if needed

Cardioversion works by delivering a synchronized electrical shock that depolarizes all cardiac cells simultaneously, allowing the heart's natural pacemaker to regain control and restore normal rhythm. It's crucial to synchronize the shock with the R wave to avoid inducing ventricular fibrillation. The choice of anticoagulation therapy should be based on the patient's thromboembolic risk profile, as outlined in the guidelines 1.

From the Research

Indications for Electrical Cardioversion

The indications for electrical cardioversion are as follows:

• Atrial fibrillation (AF) and atrial flutter are the primary indications for electrical cardioversion 2, 3, 4, 5, 6
• Electrical cardioversion is preferred for persistent AF, especially if the arrhythmia has lasted more than 24-48 hours 2
• It is also used for paroxysmal AF, particularly when drug therapy is ineffective or not tolerated 2
• Electrical cardioversion can be used in patients with atrial arrhythmias who are symptomatic and have not responded to medical therapy 3, 6

Patient Selection

Patient selection for electrical cardioversion involves considering the following factors:

• The presence of atrial fibrillation or atrial flutter 2, 3, 4, 5, 6
• The duration of the arrhythmia 2
• The presence of underlying heart disease or other comorbidities 4, 6
• The use of anticoagulation therapy to prevent thromboembolic complications 3, 6

Procedure-Related Factors

Procedure-related factors that influence the outcome of electrical cardioversion include:

• The use of biphasic cardioverters, which have been shown to be more effective than monophasic cardioverters 4
• The energy level used for cardioversion, with higher energy levels associated with fewer tachyarrhythmic complications 5
• The use of transesophageal echocardiography (TEE) before cardioversion, which can help identify patients at high risk of thromboembolic complications 6