Katherine Allan

St. Michael's Hospital - Unity Health Toronto · Cardiology

Background: Early cardiopulmonary resuscitation (CPR) and defibrillation are critical for favorable outcomes after sudden cardiac arrest (SCA). Scientific evidence supports CPR and Automated External Defibrillator (AED) training in school-age children. Few studies have used gamified, video-based training to teach students. This national project aim...

Background Sudden cardiac death (SCD) is a devastating event and a leading cause of mortality, globally. In the young (2-45 years), SCD is often attributable to a heritable cardiac condition. Death investigators are often responsible for investigating the cause of death and communicating their results and risk of heritable cardiac conditions with f...

Background Disparities in atrial fibrillation ablation rates have been studied previously, with a focus on either patient characteristics or systems factors, rather than geographic factors. The impact of electrophysiology (EP) centre practice patterns on ablation rates has not been well studied. Methods This population-based cohort study used link...

Objectives The coronavirus disease 2019 (COVID-19) pandemic has impacted public health systems and individuals' behaviour, with decreasing survival rates among out-of-hospital cardiac arrest (OHCA) patients. Bystander cardiopulmonary resuscitation (CPR) improves OHCA outcomes, which may have been affected by COVID-19. We sought to understand the im...

Background Patients resuscitated from out-of-hospital cardiac arrest (OHCA) are at high risk of recurrence, posing a substantial burden on healthcare systems. Despite the established benefit of implantable cardioverter defibrillator (ICD) therapy in many such patients, and recommendations by guidelines, few studies have described the proportion of...

Background: Worldwide, bystander CPR rates are low; one effective way to increase these rates is to train schoolchildren; however, the most effective way to train them is currently unknown. Methods: This systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies, evaluated whether CPR training for school...

Background: Out-of-hospital cardiac arrest (OHCA) is a major global health challenge, characterized by poor survival outcomes worldwide. Resource-limited settings are burdened with suboptimal emergency response and worse outcomes than high-resource areas. Engaging the community in the response to OHCA has the potential to improve outcomes, althoug...

This scoping review summarizes existing approaches, benefits, and barriers to shared decision-making (SDM) in the context of sports cardiology. Among 6,058 records screened, 37 articles were included in this review. Most included articles defined SDM as an open dialogue between the athlete, healthcare team, and other stakeholders. The benefits and...

Background The role of multidisciplinary clinics for psychosocial care is increasingly recognized for those living with inherited cardiac conditions (ICC). In Canada, access to healthcare providers differ between clinics. Little is known about the relationship between access to specialty care and a patient's ability to cope with, and manage their c...

Background: Sudden cardiac death (SCD) in younger individuals is frequently caused by heritable cardiac conditions. The unexpected nature of SCD leaves families with many unanswered questions and an insufficient understanding of the cause of death and their own risk for heritable disease. We explored the experiences of families of young SCD victim...

Introduction: Atrial fibrillation (AF) ablation is increasingly commonly performed for patients with symptomatic AF. In Canada, AF ablation occurs at specialized electrophysiology centers (“EP centers”), which are clustered in major urban centers. Hypothesis: People with AF who live closer to an EP center are more likely to undergo an AF ablation....

Introduction: Exercise restriction following the identification of a cardiovascular condition can profoundly impact the identity, career, and well-being of athletes. Shared decision-making (SDM) is emerging as the standard of care to guide recommendations for athletes at risk of cardiovascular events. This scoping review summarizes existing approac...

Cardiac arrest leading to death and “sudden cardiac death” (SCD) may refer implicitly to situations where death is unexpected and primarily of cardiac cause. National and international societies have published differing definitions for the various terms relating to cardiac arrest and SCD. We highlight the controversies in defining SCD, including th...

Background Existing studies have shown conflicting results regarding the relationship of sex with survival after out of hospital cardiac arrest (OHCA). This systematic review evaluates the association of female sex with survival to discharge and survival to 30 days after non-traumatic OHCA. Methods We searched Medline, Embase, CINAHL, Web of Scien...

Sudden cardiac arrest (SCA) is a common event, affecting almost 400,000 individuals annually in North America. Initiation of cardiopulmonary resuscitation (CPR) and early defibrillation using an automated external defibrillator (AED) are critical for survival, yet many bystanders are reluctant to intervene. Digital technologies, including mobile de...

Background Approximately 10% of persons suffering out of hospital cardiac arrest (OHCA) treated by paramedics survive to hospital discharge. Survival varies up to 19.2% between urban centres and rural areas. Our goal was to investigate the differences in OHCA survival between urban centres and rural areas. Methods This was a retrospective cohort s...

The pursuit of more efficient patient-friendly health systems and reductions in tertiary health services use has seen enormous growth in the application and study of remote patient monitoring systems for cardiovascular patient care. While there are many consumer-grade products available to monitor patient wellness, the regulation of these technolog...

BACKGROUND Out-of-hospital cardiac arrest (OHCA) usually occurs unexpectedly and is frequently attributed to an underlying cardiac cause. Previous studies have indicated that some OHCA patients may seek medical help in the weeks to months leading up to their OHCA event. The aim of this study was to assess the prior healthcare utilization burden of...

Cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) training in schools are mandated in the Ontario high school curriculum. We surveyed schools to understand the scope of this training, including its barriers and facilitators. We recruited 120 (58.5%) elementary, 25 (12.2%) middle, and 60 (29.3%) high schools. Almost 60%...

Background The ongoing COVID-19 pandemic has exposed a work-life (im)balance that has been present but not openly discussed in medicine, surgery and science for decades. The pandemic has exposed inequities in existing institutional structure and policies concerning clinical workload, research productivity, and/or teaching excellence inadvertently p...

This is the summary publication of the International Liaison Committee on Resuscitation’s 2020 International Consensus on First Aid Science With Treatment Recommendations. It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administra...

This is the summary publication of the International Liaison Committee on Resuscitation’s 2020 International Consensus on First Aid Science With Treatment Recommendations . It addresses the most recent published evidence reviewed by the First Aid Task Force science experts. This summary addresses the topics of first aid methods of glucose administr...

Background Catheter ablation (CA) is performed in patients with atrial fibrillation (AF) to reduce symptoms and improve health related quality of life (HRQL). Methods This systematic review and meta-analysis of randomized controlled trials (RCTs) evaluated CA of any energy modality compared to antiarrhythmic drugs (AADs) using inverse-variance ran...

Aims To determine if mathematical optimization of in-hospital defibrillator placements can reduce in-hospital cardiac arrest-to-defibrillator distance compared to existing defibrillators in a single hospital. Methods We identified treated IHCAs and defibrillator placements in St. Michael's Hospital in Toronto, Canada from Jan. 2013 to Jun. 2017 an...

Background: Numerous studies have shown significant neighbourhood level variation in out-of-hospital cardiac arrest (OHCA) incidence rates, however, few have provided an explanation for these disparities beyond traditional socioeconomic measures. Methods: This was a retrospective study using data from a large population-based OHCA database (Resc...

Background: Heat stroke is an emergent condition characterized by hyperthermia (>40 °C/>104 °F) and nervous system dysregulation. There are two primary etiologies: exertional which occurs during physical activity and non-exertional which occurs during extreme heat events without physical exertion. Left untreated, both may lead to significant morbi...

Introduction: Delays in defibrillation of in-hospital cardiac arrests (IHCAs) can reduce the likelihood of survival. Mathematical optimization has been shown to improve public location defibrillator placement but has not been applied to in-hospital defibrillator placement. Objective: To determine if mathematical optimization of in-hospital defibril...

Introduction: The incidence and details of sudden cardiac arrest (SCA) during exercise in the general population are not well described. We describe a cohort ages 2-85 who experienced an SCA within ≤ 1 hour of moderate to vigorous activity in 4 metropolitan areas of British Columbia, Canada. Methods: We reviewed prehospital records of consecutive o...

Background: Hypertrophic cardiomyopathy (HCM) is considered a leading cause of sudden cardiac death (SCD) in younger people. The incidence of HCM-related SCD and its relationship to exercise have not been well studied in large comprehensive studies outside of tertiary care settings. This study sought to estimate the incidence of HCM-related SCD an...

Sudden cardiac arrest (SCA) has a devastating impact on both the family of the patient with SCA and his or her community. Because of various methodological differences between studies, reported incidence rates for SCA can vary widely, emphasizing the lack of clarity with respect to the true scope of this phenomenon. In recognition of the importance...

Background It is believed that most sudden cardiac arrests (SCAs) in young people occur in previously healthy people with rare risk factors for sudden death. Few studies have investigated large populations with complete ascertainment. Our objective was to use multisource records to identify and classify all out‐of‐hospital cardiac arrests in the Gr...

Introduction: Identifying those at risk for Sudden Cardiac Death (SCD) is imperative to prevent future events. There may be risk factors (RFs), triggers or warning symptoms preceding the SCD that could help identify those at greatest risk. Methods: This retrospective study included out-of-hospital cardiac arrests (OHCAs) of “no obvious cause” in th...

Worldwide, over 230 million adults have major noncardiac surgery each year. Although surgery can improve quality and duration of life, it can also precipitate major complications. Moreover, a substantial proportion of deaths occur after discharge. Current systems for monitoring patients postoperatively, on surgical wards and after transition to hom...

Background The incidence of sudden cardiac arrest during participation in sports activities remains unknown. Preparticipation screening programs aimed at preventing sudden cardiac arrest during sports activities are thought to be able to identify at-risk athletes; however, the efficacy of these programs remains controversial. We sought to identify...

Introduction There has been increasing interest in pragmatic trials methodology. As a result, tools such as the Pragmatic-Explanatory Continuum Indicator Summary-2 (PRECIS-2) are being used prospectively to help researchers design randomised controlled trials (RCTs) within the pragmatic-explanatory continuum. There may be value in applying the PREC...

Introduction Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia and causes patients considerable burden; symptoms such as palpitations and dyspnoea are common, leading to frequent emergency room visits. Patients with AF report reduced health-related quality of life (HQOL) compared with the general population; thus, treatments focus o...

Aim: To use a novel methodology to assess the incidence and specific causes of Out-of-Hospital Cardiac Arrest (OHCA) within a young urban cohort. Methods: All EMS attended OHCA patients in a large urban area, between 2009-2012, aged 2-45 years, treated or untreated, who died or survived, and that were designated as "no obvious cause" etiology by...

Traditional variables used to explain survival following out-of-hospital cardiac arrest (OHCA) account for only 72% of survival, suggesting that other unknown factors may influence outcomes. Research on other diseases suggests that neighbourhood factors may partly determine health outcomes. Yet, this approach has rarely been used for OHCA. This wor...

Background: Death due to out-of-hospital cardiac arrest (OHCA) is most commonly attributed to “no obvious cause” after review of the prehospital and in-hospital documentation. To establish cause of death in younger patients, autopsy and toxicology data are important, especially in younger patients. We examined the probable cause of death in a large...

Background: Out-of-Hospital-Cardiac Arrest (OHCA) in young individuals is a tragic and unexpected event, often occurring in seemingly healthy individuals. We examined the etiologies and medications in a large urban cohort of young sudden death patients in order to ascertain the accuracy of this assumption. Methods: A prospective population-based re...

Background: Sudden cardiac arrest (SCA) is devastating for the patient’s family, friends, and community. There is limited information on its identifiable familial predisposition. Objectives: To evaluate the familial risk pattern for SCA in family members of cases compared to age-and-sex matched control groups. Incidence of prior symptoms and SCA tr...

Objectives: We developed and tested a training method for basic life support incorporating defibrillator feedback during simulated cardiac arrest (CA) to determine the impact on the quality and retention of CPR skills. Methods: 298 subjects were randomized into 3 groups. All groups received a 2h training session followed by a simulated CA test s...

Introduction: Traditional Utstein factors for an out of hospital cardiac arrest (OHCA) have been extensively investigated, with numerous studies evaluating economic status for association with survival. Few studies have evaluated neighbourhood factors collectively as determinants of cardiac arrest outcomes. This will be the first multifactorial Can...

Introduction: Out of hospital cardiac arrest (OHCA) incidence rates may vary across regions. Prior studies measured OHCA variability by the location of the OHCA, rather than the victim's place of residence, thereby omitting potentially important demographic predictors of OHCA. Objectives: To measure variability of OHCA rates by residential address...

Percutaneous coronary intervention (PCI) appears to be superior to in-hospital fibrinolysis for most patients with ST-elevation myocardial infarction (STEMI). However, few hospitals have PCI capability. The optimal prehospital strategy for facilitating rapid coronary reperfusion in STEMI patients is unclear. We sought to determine whether direct tr...

Prehospital termination of resuscitation rules have been derived for Emergency Medical Technician-Paramedics providing advanced life support care and defibrillation-only Emergency Medical Technicians providing basic life support care. We sought to externally validate each rule on a prospective cohort of prehospital cardiac arrest patients to determ...

Objectives: The primary aim was to derive a new termination of resuscitation (TOR) clinical prediction rule for advanced life support paramedics (ALS) and to measure both its pronouncement rate and diagnostic test characteristics. Secondary aims included measuring the test characteristics of a previously derived and published basic life support te...

The zone of calcified cartilage is the mineralized region of articular cartilage that anchors the hyaline cartilage to the subchondral bone and serves to disperse mechanical forces across this interface. In an attempt to mimic this zonal organization, we have developed the methodology to form biphasic constructs composed of cartilaginous tissue anc...