~500 spots leftby Jun 2026

Electrode Positioning for Atrial Fibrillation Cardioversion

(SHOCK-VECTOR Trial)

Recruiting in Palo Alto (17 mi)
+1 other location
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: McMaster University
Disqualifiers: Insufficient anticoagulation, Anatomic contraindication, others
No Placebo Group

Trial Summary

What is the purpose of this trial?

Atrial fibrillation is the most common heart rhythm disorder (arrhythmia) worldwide. Nearly 40 million people are affected by atrial fibrillation worldwide, and this number is expected to increase by over 50% by 2050. Atrial fibrillation can cause strokes, heart attacks, heart failure, poor quality of life and even death. Almost half a million deaths worldwide are expected to be related to atrial fibrillation by 2050, and many billions of dollars are spent on atrial fibrillation related healthcare in North America every year. We believe health outcomes for patients with atrial fibrillation, and healthcare costs associated with treating atrial fibrillation could be improved by optimizing existing treatments for atrial fibrillation and maximizing the likelihood of restoring normal heart rhythm. This allows them to benefit from lower stroke risk, better heart function, fewer symptoms and increased quality of life. Restoring normal sinus rhythm earlier prevents atrial fibrillation from causing permanent structural damage to the heart that in turn, makes atrial fibrillation intractable. Furthermore, patients in whom initial attempts to control atrial fibrillation are unsuccessful frequently require more medications or invasive catheter ablation procedures which are costly and carry substantial risk. Electrical cardioversion is the main way physicians restore normal heart rhythm. In this procedure, the heart is "shocked" back into normal rhythm using two electrodes on the chest. Done correctly, this procedure is safe and effective. Many things are known about electrical cardioversion, for example, the best type and amount of electricity to use. What we don't know is the best position of the electrodes on the chest and whether applying direct, physical pressure to the electrodes makes cardioversion more successful. Our prior research suggests that improving positioning and applying pressure may improve cardioversion, but this finding needs to be verified with a rigorous, dedicated trial. This study will demonstrate whether front-to-back, or front-to-side placement of the electrodes is more effective for electrical cardioversion of atrial fibrillation. We will also demonstrate whether manually applying pressure to the electrodes makes cardioversion more effective. Should our trial demonstrate a benefit for these techniques, we expect them to be universally applied around the world. Because hundreds of thousands of cardioversions are done each year, even small increases in cardioversion success means thousands fewer patients progress to needing more medications or invasive procedures to manage their atrial fibrillation. We will study consenting adults presenting for non-urgent cardioversion of their atrial fibrillation. After explaining the study to participants and gaining their consent, we will randomly assign them to front-to-side or front-to-back electrode placement. Patients who remain in atrial fibrillation after the first shock will randomly receive either manual pressure or not. We will compare the success of cardioversion for front-side versus front-back electrode placement, and for manual pressure versus none. We will evaluate success by using electrocardiograms to assess for restoration of the heart rhythm back to normal. We hypothesize that anterolateral electrode positioning is superior to anteroposterior electrode positioning. We also hypothesize that manual pressure is effective relative to none, when applied in patients who have had one unsuccessful shock already.

Will I have to stop taking my current medications?

The trial protocol does not specify whether you need to stop taking your current medications. It's best to discuss this with the trial coordinators or your doctor.

What data supports the effectiveness of the treatment Anterolateral electrode position, Front-to-side electrode placement, Anteroposterior electrode position, Electrical Cardioversion, Cardioversion Therapy, Manual pressure, Manual pressure application, Physical pressure technique for Atrial Fibrillation Cardioversion?

Research shows that the anterior-lateral electrode position is more effective than the anterior-posterior position for cardioversion of atrial fibrillation, especially in patients who have received fewer than five shocks, are 60 years or older, and have a larger left atrial diameter.12345

Is electrode positioning for atrial fibrillation cardioversion safe for humans?

Studies suggest that both anterior-lateral and anterior-posterior electrode positions are safe for use in humans during cardioversion for atrial fibrillation, with no indication that one is less safe than the other.23456

How does the electrode positioning treatment for atrial fibrillation differ from other treatments?

The treatment involves using different electrode positions, either anterolateral (front-to-side) or anteroposterior (front-to-back), to deliver an electrical shock to the heart and restore normal rhythm. Anteroposterior positioning is often considered more effective because it targets the left atrium, which is located at the back of the chest and is crucial in maintaining atrial fibrillation.14567

Research Team

Eligibility Criteria

This trial is for consenting adults set to undergo non-emergency electrical cardioversion for Atrial Fibrillation or Flutter. Participants must be adequately anticoagulated as per guidelines, or have had an echocardiogram to rule out heart clots. Those with skin conditions or wounds preventing electrode placement cannot join.

Inclusion Criteria

I am an adult who has agreed to a planned electrical cardioversion for Atrial Fibrillation or Flutter.

Exclusion Criteria

I haven't had the proper blood thinning treatment or a specific heart scan.
I cannot have treatments placed on certain parts of my body due to skin conditions or wounds.

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

1-2 weeks

Treatment

Participants undergo electrical cardioversion with randomized electrode placement and potential manual pressure application

At time of intervention
1 visit (in-person)

Follow-up

Participants are monitored for cardioversion success and any adverse effects

4 weeks
1 visit (in-person), 1 follow-up call

Treatment Details

Interventions

  • Anterolateral electrode position (Procedure)
  • Anteroposterior electrode position (Procedure)
  • Manual pressure (Behavioural Intervention)
Trial OverviewThe study tests whether placing electrodes on the front-to-back (anteroposterior) or front-to-side (anterolateral) of the chest and applying manual pressure improves the success of restoring normal heart rhythm in patients with atrial fibrillation.
Participant Groups
2Treatment groups
Active Control
Group I: Anterolateral shock vectorActive Control2 Interventions
Patients with electrodes placed on the chest to obtain an anterolateral (front-to-side placement; also known as anteroapical) shock vector. If first shock is unsuccessful, participants who proceed to a second shock will be randomized to manual pressure versus none but electrode placement will remain the same.
Group II: Anteroposterior shock vectorActive Control2 Interventions
Patients with electrodes placed on the chest to obtain an anteroposterior (front-to-back placement) shock vector. If first shock is unsuccessful, participants who proceed to a second shock will be randomized to manual pressure versus none but electrode placement will remain the same.

Find a Clinic Near You

Research Locations NearbySelect from list below to view details:
Hamilton Health SciencesHamilton, Canada
St Joseph's Healthcare HamiltonHamilton, Canada
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Who Is Running the Clinical Trial?

McMaster University

Lead Sponsor

Trials
936
Patients Recruited
2,630,000+

Findings from Research

In a study of 90 patients undergoing elective cardioversion for atrial fibrillation, the position of electrode pads (anteroanterior vs. anteroposterior) did not significantly affect the success rate of cardioversion, which was 81% overall.
Both electrode positions required similar energy levels for successful cardioversion, indicating that factors like the duration of atrial fibrillation are more critical for predicting success than the pad placement.
Randomised comparison of electrode positions for cardioversion of atrial fibrillation.Mathew, TP., Moore, A., McIntyre, M., et al.[2019]
Anteriolateral versus anterior-posterior electrodes in external cardioversion of atrial fibrillation: A systematic review and meta-analysis of clinical trials.Motawea, KR., Mostafa, MR., Aboelenein, M., et al.[2023]
[Electrode position in elective electrical cardioversion of atrial fibrillation. A randomized study].Muñoz-Martínez, T., Castañeda-Saiz, A., Vinuesa-Lozano, C., et al.[2016]
Anterior-Lateral Versus Anterior-Posterior Electrode Position for Cardioverting Atrial Fibrillation.Schmidt, AS., Lauridsen, KG., Møller, DS., et al.[2022]
Effect of electrode position on the outcome of cardioversion.Kirchhof, P., Borggrefe, M., Breithardt, G.[2014]
Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation.Siaplaouras, S., Buob, A., Rötter, C., et al.[2006]
Anteroposterior Versus Anterolateral Electrode Position for Direct Current Cardioversion of Atrial Fibrillation: A Meta-Analysis of Randomised Controlled Trials.Virk, SA., Rubenis, I., Brieger, D., et al.[2022]

References

Randomised comparison of electrode positions for cardioversion of atrial fibrillation. [2019]
Anteriolateral versus anterior-posterior electrodes in external cardioversion of atrial fibrillation: A systematic review and meta-analysis of clinical trials. [2023]
[Electrode position in elective electrical cardioversion of atrial fibrillation. A randomized study]. [2016]
Anterior-Lateral Versus Anterior-Posterior Electrode Position for Cardioverting Atrial Fibrillation. [2022]
Effect of electrode position on the outcome of cardioversion. [2014]
Randomized comparison of anterolateral versus anteroposterior electrode position for biphasic external cardioversion of atrial fibrillation. [2006]
Anteroposterior Versus Anterolateral Electrode Position for Direct Current Cardioversion of Atrial Fibrillation: A Meta-Analysis of Randomised Controlled Trials. [2022]