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Evaluating Electrophysiology Testing for Unexplained Cardiac Arrest Survivors

The Role of Electrophysiology Testing in Survivors of Unexplained Cardiac Arrest

Observational Western University, Canada · NCT03079414

This study tests if a special heart test can help find hidden heart problems in people who have survived a cardiac arrest with no clear cause.

Quick facts

Study typeObservational
Enrollment100 (estimated)
SexAll
SponsorWestern University, Canada Academic / other
Locations21 sites (Los Angeles, California and 20 other locations)
Trial IDNCT03079414 on ClinicalTrials.gov

What this trial studies

This study investigates the role of invasive electrophysiology testing in patients who have experienced unexplained cardiac arrest. It aims to determine whether this diagnostic approach can uncover underlying cardiac conditions that are not identified through standard diagnostic methods. The study focuses on individuals who have suffered cardiac arrests without evident coronary or structural heart disease, assessing the potential benefits of electrophysiology studies in these cases. By refining the diagnostic process, the research seeks to improve outcomes for patients with unexplained cardiac events.

Who should consider this trial

Good fit: Ideal candidates for this study are individuals who have experienced unexplained cardiac arrest requiring cardioversion or defibrillation.

Not a fit: Patients with known coronary artery disease or other specific cardiac conditions that explain their cardiac arrest will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better identification and management of patients at risk for sudden cardiac death.

How similar studies have performed: Previous studies have shown mixed results regarding the utility of electrophysiology testing in similar contexts, making this approach both relevant and potentially novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Unexplained cardiac arrest requiring cardioversion or defibrillation
2. Willing and able to sign informed consent

Exclusion Criteria:

1. Coronary artery disease (stenosis \> 50%) and clinical findings consistent with an ischemic arrest
2. Reduced left ventricular function (left ventricular ejection fraction \< 50%) on echocardiogram or cardiac MRI.
3. Persistent resting QTc \> 460 msec for males and 480 msec for females
4. Resting QTc \< 350 msec
5. Type I Brugada ECG with \>/= 2 mm ST elevation in V1 and/or V2 (Spontaneous or Drug-Induced)
6. Polymorphic or bidirectional ventricular tachycardia observed with exertion on exercise treadmill testing
7. Clinical, electrocardiographic, and/or imaging findings consistent with a diagnosis of arrhythmogenic right ventricular cardiomyopathy
8. Myocarditis
9. Reversible cause of cardiac arrest such as marked hypokalemia (\<2.8 mmol/l) or drug overdose sufficient in severity without other cause to explain the cardiac arrest.
10. Arrhythmic mitral valve prolapse syndrome
11. Documented ventricular fibrillation initiated by a short-coupled premature ventricular contraction

Where this trial is running

Los Angeles, California and 20 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
View on ClinicalTrials.gov → Find more trials like this →
Conditions Sudden Cardiac DeathCardiac ArrhythmiaElectrophysiology StudyGenetics
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.