What is the joules of energy used for Direct Current Cardioversion (DCR) for adult Atrial Fibrillation (AF)?

From the Guidelines

For direct current cardioversion (DCR) in adult atrial fibrillation (AF), the recommended energy levels typically start at 120-200 joules using a biphasic defibrillator, as supported by the 2010 American Heart Association guidelines 1.

Key Considerations

• The initial energy dose for cardioversion of atrial fibrillation is recommended to be 120 to 200 J (Class IIa, LOE A) 1.
• If the initial shock fails, providers should increase the dose in a stepwise fashion.
• Cardioversion with monophasic waveforms should begin at 200 J and increase in stepwise fashion if not successful (Class IIa, LOE B) 1.
• Some studies suggest that higher initial energy may be more effective, with a study showing immediate success rates of 14% with 100 J, 39% with 200 J, and 95% with 360 J, respectively 1.

Clinical Recommendations

• Prior to cardioversion, patients should be adequately anticoagulated for at least 3 weeks if AF duration exceeds 48 hours or is unknown, or a transesophageal echocardiogram should be performed to rule out left atrial thrombus.
• Procedural sedation is necessary, and the shock should be synchronized to the R wave to avoid inducing ventricular fibrillation.
• The anterolateral paddle position is most commonly used, with one paddle placed to the right of the upper sternum and the other over the cardiac apex.
• Higher energy levels may be required for patients who are obese or have high thoracic impedance.

Important Considerations for Specific Patient Populations

• When appropriate precautions are taken, cardioversion of AF is safe in patients with implanted pacemaker or defibrillator devices 1.
• The implanted device should be interrogated and, if necessary, reprogrammed before and after cardioversion to ensure appropriate function.

From the Research

Energy Settings for DCR in Adult AF

• The optimal energy setting for direct-current cardioversion (DCCV) in adult atrial fibrillation (AF) has been studied, with some research suggesting that a higher initial energy setting may be more effective 2, 3.
• A study published in 2003 found that an initial energy setting of 360 joules (J) resulted in a significantly higher success rate for DCCV compared to a lower initial energy setting of 200 J (96.0% vs 75.4%, P = 0.003) 2.
• Another study published in 2001 found that the probability of success on the first shock in AF of > 30 days duration was 5.5% at < 200 J, 35% at 200 J, and 56% at 360 J 3.
• The use of a higher initial energy setting of 360 J may also result in less skeletal muscle damage and no cardiac muscle damage, as well as a lower average number of shocks delivered 2.

Comparison of Energy Settings

• A comparison of energy settings for DCCV in adult AF found that an initial energy setting of > or =360 J can achieve cardioversion more efficiently in patients with AF of longer duration 3.
• The study also found that shocks of < 200 J had a low probability of success, particularly in patients with AF of longer duration 3.

Clinical Considerations

• The choice of energy setting for DCCV in adult AF should take into account the individual patient's characteristics and medical history, as well as the potential risks and benefits of the procedure 4, 5, 6.
• Effective periprocedural anticoagulation is essential to prevent thromboembolic complications, particularly during the first week after the procedure 4.
• The timing of cardioversion and the use of transoesophageal echocardiography may also be important considerations in the management of AF 4, 5.