Compares two defibrillator devices for restoring normal heart rhythm in atrial fibrillation
Compares two defibrillator devices in adults with atrial fibrillation undergoing electrical cardioversion.
Plain-language title generated from the registry record
Registry title: MAX - SHOCK Clinical Trial
Key facts
- Where
- Ottawa, CanadaSee the site
AI summary: who the study is looking for
From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.
The trial is looking for adults with persistent atrial fibrillation who are scheduled for an elective cardioversion at UOHI. It compares two defibrillators with different maximum shock energy.
- Age
- Older than 18 years
- Sex
- All sexes can join.
- Disease stage
- Persistent atrial fibrillation, scheduled for elective cardioversion at UOHI.
Main reasons for not taking part
- Known blood clot in the left atrial appendage
- Cannot safely take appropriate anticoagulation (blood thinner) treatment
- Already taking part in another randomized clinical trial
Read by machine on 9 November 2026.
Where in Canada
- University of Ottawa Heart InstituteOttawa, CanadaTaking people
Questions to ask the study team
- How often do I need to come in, and for how long each time?
- Are travel costs paid?
- Can I keep my own doctor?
- What happens if I want to stop?
Trial details
- Who runs it
- Ottawa Heart Institute Research Corporation
- Trial code
- NCT06556667
- Record updated
- 3 February 2026
- Original description
Can Electrical Cardioversion (ECV) for AF be improved. It is the preferred method to restore sinus rhythm in patients with AF in whom a rhythm-control strategy is pursued.Read full original descriptionShow less
Comparison of Maximum Energy Shocks From Two Defibrillator Vendors MAX - SHOCK- A Randomized Controlled Clinical Trial
Can Electrical Cardioversion (ECV) for AF be improved. It is the preferred method to restore sinus rhythm in patients with AF in whom a rhythm-control strategy is pursued.
Hypothesis:
ECV success rates will be greater with a biphasic defibrillator with maximum energy of 360J (® Physio-Control) compared to a biphasic defibrillator with maximum energy of 200J (® Zoll)
Inclusion: Patients age > 18 years; Persistent atrial fibrillation; Scheduled for elective cardioversion at UOHI; Patient is within the circle of care of UOHI Electrophysiology staff.
Exclusion: Known left-atrial appendage thrombus; Contraindication to appropriate anticoagulation; Patient is included in another randomized clinical trial; Patient does not meet all of the above listed inclusion criteria.