The Ottawa AF Cardioversion Protocol

Study design:

All eligible and consenting patients will undergo elective electrical cardioversion for atrial fibrillation (AF) using the Ottawa AF protocol.The fact that the physician follows the protocol makes this experimental. Aside from following the protocol, subjects will receive standard care before, during and after the procedure. Outcomes of the procedure and clinical features know to affect cardioversion efficacy will be collected. These will be compared to a group of 500 previous patients who underwent elective electrical cardioversion for AF at the Heart Institute.

Methodology:

The Ottawa AF protocol prescribes the electrical energy dose, the electrode position and the application of pressure to the electrodes the physician will use. The individual elements of the protocol (energy dose, electrode position and pressure application) are often used by physician in clinical practice but not necessarily in the step by step order.

The Ottawa AF protocol prescribes the following:

• the starting energy dose (200 J) and electrode placement (anterior-posterior)
• the second electrode placement (anterior-lateral) if the first shock is not successful
• addition of pressure to electrodes if second shock is not successful
• step up of energy dose (360 J) along with pressure to electrodes if third shock is not successful
• optional further steps at physician's choice if fourth shock is not successful

Inclusion criteria

• Documented atrial fibrillation within last 12 months
• On continuous systemic oral anticoagulation for 28 days prior to the day of cardioversion or must have undergone a recent (< 48 hrs) trans-esophageal echocardiogram prior to the day of cardioversion
• Able to provide informed consent

Exclusion criteria

• Presence of intracardiac thrombus
• Pregnancy