The Ottawa AF Cardioversion Protocol
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Interventional

Summary: 
      Atrial fibrillation is an abnormal heart rhythm in which the top chambers of the heart (the
      atrial chambers) beat very fast. Electrical cardioversion is a technique to convert heart
      rhythm from AF to normal rhythm. The technique sends out a brief electric shock to the heart
      through electrodes (paddles or skin patches) applied to the outside of the chest wall. The
      shock resets the heart rhythm back to its normal pattern.

      This technique is practiced at many hospitals, including the Heart Institute, and is not
      experimental. However no detailed national or international guidelines exist to assist
      physicians in performing cardioversion. Physicians use a variety of methods. Electrical
      cardioversion does not always restore normal rhythm. Adjusting the electrical energy dose,
      changing the electrode position and applying pressure to the electrodes may improve the
      success rate.

      This study will look at the safety and efficacy of a protocol (step by step method) for
      electrical cardioversion. The 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 purpose of this study is to get all doctors to follow a standard protocol 'the Ottawa AF
      cardioversion protocol'. We think that using this protocol will improve overall cardioversion
      success rates. The results of this study may change usual practice in Canada and in other
      countries.

      All supplies, equipment and medications used in the protocol cardioversion are approved by
      Health Canada.

      We estimate that 389 participants from the University of Ottawa Heart Institute will be
      enrolled in the study over the next 2 years. The results will be compared with a group of
      previous patients.
    

Detailed description: 
      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
    

Intervention name(s): Lifepak 20E Defibrillator, Licence No: 61944
Intervention type(s): Device
Intervention description(s): Intervention will be carried out using Health Canada approved devices for electrical cardioversion, following the steps pre-specified in the Ottawa AF Protocol.
Ottawa AF Cardioversion
Other intervention name(s): -HEARTSTART XL, Licence No: 24413.; -Kendall 1010P Multi-function Defibrillation Electrodes, Licence No: 21857
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: cardioversion; electrical cardioversion; atrial fibrillation; cardioversion protocol