Canadian electrophysiology (EP) fellowship programs have evolved in an ad hoc fashion over 30 years. This evolution has occurred in many fields in medicine and is natural when innovators and pioneers attract research fellows who help change the status quo from predominantly research to a predominantly clinical application and focus. Fellows not only push their supervisors and their centres into new areas of inquiry but also function at the most advanced level to encourage and teach junior trainees and to provide examples of excellence to residents, medical students, and other health professionals. Funding for fellows has never been provided in the traditional way through the Ministry of Health or the Ministry of Advanced Education. Each Canadian centre has over the years found novel ways to fund fellowship programs, and many centres have used value-adds from procurement programs. These sources of funding are eroding as provincial government agencies are beginning to assume procurement responsibilities and local flexibility to fund fellowships is lost. In particular, provincial government agencies feel that valuable financial resources should be restricted to Canadian trainees only, despite the international consensus that fellowship is an essential time for advanced trainees to travel abroad to acquire a broad a range of experience, learn new techniques and approaches, make lifelong research connections, and hopefully return home with these skills and expertise. This article summarizes the long history of EP fellowship training in Canada, as well as EP fellowship experiences at home and abroad by Canadian electrophysiologists, in an attempt to contextualize these new realities.
Epinephrine infusion may unmask latent genetic conditions associated with cardiac arrest, including long-QT syndrome and catecholaminergic polymorphic ventricular tachycardia (VT).
Patients with unexplained cardiac arrest (normal left ventricular function and QT interval) and selected family members from the Cardiac Arrest Survivors with Preserved Ejection Fraction Registry (CASPER) registry underwent epinephrine challenge at doses of 0.05, 0.10, and 0.20 µg/kg per minute. A test was considered positive for long-QT syndrome if the absolute QT interval prolonged by = 30 ms at 0.10 µg/kg per minute and borderline if QT prolongation was 1 to 29 ms. Catecholaminergic polymorphic VT was diagnosed if epinephrine provoked = 3 beats of polymorphic or bidirectional VT and borderline if polymorphic couplets, premature ventricular contractions, or nonsustained monomorphic VT was induced. Epinephrine infusion was performed in 170 patients (age, 42 ± 16 years; 49% men), including 98 patients with unexplained cardiac arrest. Testing was positive for long-QT syndrome in 31 patients (18%) and borderline in 24 patients (14%). Exercise testing provoked an abnormal QT response in 42% of tested patients with a positive epinephrine response. Testing for catecholaminergic polymorphic VT was positive in 7% and borderline in 5%. Targeted genetic testing of abnormal patients was positive in 17% of long-QT syndrome patients and 13% of catecholaminergic polymorphic VT patients.
Epinephrine challenge provoked abnormalities in a substantial proportion of patients, most commonly a prolonged QT interval. Exercise and genetic testing replicated the diagnosis suggested by the epinephrine response in a small proportion of patients. Epinephrine infusion combined with exercise testing and targeted genetic testing is recommended in the workup of suspected familial sudden death syndromes. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT00292032.
Recommendations for the use of genetic testing in the clinical evaluation of inherited cardiac arrhythmias associated with sudden cardiac death: Canadian Cardiovascular Society/Canadian Heart Rhythm Society joint position paper.
The era of gene discovery and molecular medicine has had a significant impact on clinical practice. Knowledge of specific genetic findings causative for or associated with human disease may enhance diagnostic accuracy and influence treatment decisions. In cardiovascular disease, gene discovery for inherited arrhythmia syndromes has advanced most rapidly. The arrhythmia specialist is often confronted with the challenge of diagnosing and managing genetic arrhythmia syndromes. There is now a clear need for guidelines on the appropriate use of genetic testing for the most common genetic conditions associated with a risk of sudden cardiac death. This document represents the first ever published recommendations outlining the role of genetic testing in various clinical scenarios, the specific genes to be considered for testing, and the utility of test results in the management of patients and their families.
Warning symptoms may provide an opportunity to diagnose genetic disorders leading to preventative therapy. We explored the symptom history of patients with apparently unexplained cardiac arrest to determine the frequency of sentinel symptoms.
Patients with apparently unexplained cardiac arrest and no evident cardiac disease underwent systematic clinical evaluation. Patients and first-degree relatives were interviewed to determine the presence of cardiac symptoms, and those with syncope underwent 2 structured Calgary Syncope Score questionnaires to determine the probable mechanism of syncope.
One hundred consecutive cardiac arrest patients (age 43.0 ± 13.4 years, 60% male) and 63 first-degree relatives (age 37.6 ± 16.3 years, 54% female) were enrolled. Previous cardiac symptoms were present in 69% of cardiac arrest patients compared to 43% of family members (P = 0.001). Prior syncope was present in 26% of cardiac arrest patients, compared to 22% of family members (P = 0.59). Twenty-four of 25 cardiac arrest patients who completed the syncope questionnaires had a syncope versus seizure score
Department of Medicine, Queen Elizabeth II Health Sciences Center and the Department of Community Health and Epidemiology, Research Methods Unit, Dalhousie University, Halifax, Nova Scotia, Canada. firstname.lastname@example.org
Circ Arrhythm Electrophysiol. 2012 Aug 1;5(4):706-13
Underuse of implantable defibrillators has been previously noted in patients at risk for sudden cardiac death, as well as for survivors of sudden cardiac death. We sought to determine the utilization rates in a primary prevention implantable cardioverter-defibrillator (ICD)-eligible population and mortality in this group compared with a group that had undergone implantation of this therapy.
A retrospective cohort of patients from April 1, 2006, to December 31, 2009, was used to define a primary prevention ICD-eligible population. Two groups were compared on the basis of ICD implantation (no-ICD versus ICD). The primary outcome measure was mortality. Of the 717 patients found to be potentially eligible for a primary prevention ICD, 116 (16%) were referred. The remaining cohort of 601 patients were compared with an existing cohort of primary prevention ICD patients (n=290). A significant survival benefit was associated with primary prevention ICD implantation (hazard ratio, 0.46; 95% CI [0.33-0.64]; P
Comment In: Circ Arrhythm Electrophysiol. 2012 Aug 1;5(4):624-522895600