Registry of Unexplained Cardiac Arrest

The recruitment status of this study is unknown because the information has not been verified recently.
Verified January 2011 by Lawson Health Research Institute.
Recruitment status was  Recruiting
Heart and Stroke Foundation of Ontario
Boston Scientific Corporation
Information provided by (Responsible Party):
Andrew Krahn, Lawson Health Research Institute Identifier:
First received: February 14, 2006
Last updated: December 7, 2012
Last verified: January 2011

The project will evaluate a standardized testing protocol in detecting the cause of cardiac arrest and familial sudden death in patients with apparently unexplained cardiac arrest. The testing is directed at the detection of rare genetic conditions that result in palpitations, blackouts and sudden death in patients and their family members. Genetic testing will be performed to validate the clinical findings.

Condition Phase
Cardiac Arrest
Long QT Syndrome
Brugada Syndrome
Catecholamine Sensitive Polymorphic Ventricular Tachycardia
Idiopathic Ventricular Fibrillation
Early Repolarization Syndrome
Phase 3

Study Type: Observational
Study Design: Observational Model: Cohort
Time Perspective: Prospective
Official Title: Cardiac Arrest Survivors With Preserved Ejection Fraction Registry (CASPER)

Resource links provided by NLM:

Further study details as provided by Lawson Health Research Institute:

Biospecimen Retention:   Samples With DNA


Estimated Enrollment: 400
Study Start Date: May 2004
Estimated Study Completion Date: June 2013
Detailed Description:

Arrhythmias caused by congenital or acquired abnormalities of cardiac K+ or Na+ channels are increasingly recognized as a cause of syncope and sudden death. Cardiac arrest in the absence of overt structural heart disease was previously considered idiopathic ventricular fibrillation (IVF). The list of causes of "unexplained" cardiac arrest (UCA) now encompasses K+ related abnormalities (Long and Short QT, Andersen's), Na+ related (Long QT3, Brugada), Ca++ related (Catecholaminergic Polymorphic Ventricular Tachycardia-CPVT), and latent cardiomyopathy. These underlying causes of cardiac arrest are overtly familial in 30-60% of cases. Clinical detection of the underlying phenotype is crucial to direct appropriate treatment, genetic testing and screening of family members.

Phenotype recognition of the range of these rare genetic conditions includes non-invasive and invasive testing to demonstrate the hallmarks of each individual condition, and exclude common causes such as ischemic or idiopathic forms of cardiomyopathy. The outcomes from this type of testing have not been assessed in a systematic fashion in patients with UCA or their family members. Phenotype-genotype correlation is necessary to develop optimal diagnostic testing in probands and screening techniques in their family members, which will result in disease-specific therapy. Genetic testing of patients with an overt phenotype demonstrates a potentially causative mutation in 50-75% of LQTS patients, and 20% of Brugada's Syndrome patients. Despite recognized mutations with phenotypic expression models, 30-80% of patients will have negative gene screening despite overt or latent clinical disease.

The proposed project is evaluating a systematic approach to clinical assessment and genetic screening of patients and families with UCA and suspected inherited arrhythmias involving:

  1. A multicenter registry of UCA patients, their family members and referred patients with familial sudden death undergoing standardized testing for evidence of primary electrical disease (PED). The single center pilot experience at the applicant's institution has proven feasibility, and has been accepted for publication in Circulation, indicating novelty. Ten centers across Canada have agreed to participate. The target is to enroll 200 UCA probands, 100 family members and 100 1st degree relatives of autopsy negative unexplained sudden death victims.
  2. DNA testing of affected individuals involving testing for LQTS, Brugada's Syndrome and CPVT. This project will partner with Dr. Michael Gollob at University of Ottawa for DNA sequencing.

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population

Unexplained cardiac arrest patients, and first degree relatives of 1) UCA patients 2) patients with known primary electrical disease or 3) unexplained sudden death before age 35


Inclusion Criteria:

  • Cardiac arrest requiring cardioversion or defibrillation.
  • Syncope with documented polymorphic ventricular tachycardia felt to be responsible for the index event.
  • First degree relative of an index case of UCA undergoing clinical testing.
  • First degree relative of a family member with UCA or sudden death before age 35 with a negative autopsy for cause of death, presumed arrhythmic.
  • First degree relative of a family member with UCA or sudden death with objective evidence of primary electrical disease, such as a diagnostic electrocardiogram (ECG), exercise test, drug infusion, or genetic testing.

Exclusion Criteria:

  • Coronary artery disease (stenosis > 50%)
  • Reduced left ventricular function (left ventricular ejection fraction [LVEF] < 50%)
  • Event managed without an implantable cardioverter defibrillator [ICD] (for follow-up portion)
  • Unwilling or unable to provide clinical follow-up (for follow-up portion)
  • Comorbidity making survival of > 1 year unlikely
  • Persistent resting QTc > 460 msec for males and 480 msec for females
  • Reversible cause of cardiac arrest such as marked hypokalemia (< 2.8 mmol/l) or drug overdose sufficient in gravity without other cause to explain the cardiac arrest
  • Hemodynamically stable sustained monomorphic ventricular tachycardia with a QRS morphology consistent with recognized forms of idiopathic ventricular tachycardia (outflow tract or apical septal)
  • Brugada's sign with e2 mm ST elevation in V1 and/or V2
  • Unwilling or unable to provide consent
  Contacts and Locations
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Please refer to this study by its identifier: NCT00292032

Contact: Andrew D Krahn, MD 519-663-3746
Contact: Bonnie M Spindler, RN 519-685-8500 ext 34748

Canada, Ontario
London Health Sciences Center Recruiting
London, Ontario, Canada, N6A 5A5
Contact: Andrew D Krahn, MD    519-663-3746 ext 1   
Contact: Bonnie M Spindler, RN    519-685-8500 ext 34748   
Principal Investigator: Andrew D Krahn, MD         
Sponsors and Collaborators
Lawson Health Research Institute
Heart and Stroke Foundation of Ontario
Boston Scientific Corporation
Principal Investigator: Andrew D Krahn, MD University of Western Ontario, Canada
  More Information

Additional publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Andrew Krahn, principal investigator, Lawson Health Research Institute Identifier: NCT00292032     History of Changes
Other Study ID Numbers: R-04-099, 10076
Study First Received: February 14, 2006
Last Updated: December 7, 2012
Health Authority: Canada: Health Canada

Keywords provided by Lawson Health Research Institute:
cardiac arrest

Additional relevant MeSH terms:
Heart Arrest
Tachycardia, Ventricular
Ventricular Fibrillation
Arrhythmias, Cardiac
Cardiovascular Diseases
Heart Diseases
Pathologic Processes
Tachycardia processed this record on March 26, 2015