The Impact of Chronic Disease on the Corrected QT (QTc) Value in Women in a British Columbia First Nations Population.

BACKGROUND: Indigenous women have higher rates of chronic disease than Indigenous men and non-Indigenous women. Long QT syndrome (LQTS) can be inherited or acquired; the latter may occur with chronic disease. A prolonged corrected QT value (QTc) is an independent risk factor for ventricular arrhythmias and sudden death, but few studies have quantified the impact of chronic disease on the QTc. We assessed the association between chronic disease and QTc prolongation in a population of First Nations women previously ascertained to study a high rate of inherited LQTS due to a unique genetic (founder) variant in their community. METHODS: This substudy focusing on women expands on the original research where patients with clinical features of LQTS and their relatives were assessed for genetic variants discovered to affect the QTc. Medical records were retrospectively reviewed and chronic diseases documented. Using multivariate linear regression, adjusting for the effect of genetic variants, age, and QTc-prolonging medications, we evaluated the association between chronic disease and the QTc. RESULTS: In total, 275 women were included. After adjustments, a prolonged QTc was associated with coronary artery disease (26.5 ms, 95% confidence interval [CI] 9.0-44.1 ms; P = 0.003), conduction system disease (26.8 ms, 95% CI 2.2-51.4 ms; P = 0.033), rheumatoid arthritis (28.9 ms, 95% CI 12.7-45.1 ms; P = 0.001), and type 2 diabetes mellitus (17.9 ms, 95% CI 3.6-32.3 ms; P = 0.015). CONCLUSIONS: This quantification of the association between chronic disease and QTc prolongation in an Indigenous cohort provides insight into the nongenetic determinants of QTc prolongation. Corroboration in other populations will provide evidence for generalisability of these results.

Indigenizing Cardiac Rehabilitation: The Role for Cultural Adaptation.

Cardiac rehabilitation (CR) is an integral component of cardiovascular care, which reduces morbidity and mortality, and improves quality of life. Largely as a result of Canada's colonial history, Indigenous communities face higher rates of cardiovascular morbidity and mortality. Indigenous Peoples in Canada have a unique cultural, historical, and geographic context that limits access to high-quality cardiovascular care, including CR, which has traditionally been delivered in an urban, hospital-based setting. Culturally adapted, holistic exercise and diet programs and CR programs have been successful in Canada, Australia, and New Zealand, demonstrating acceptability to the community, safety, and improvements in cardiovascular risk factors. Key components of a successful culturally adapted CR program include program leadership and development by Indigenous community members and key partners, cultural sensitivity training for health care providers and financial and geographic accessibility. Encouragement of traditional practices, including healthy traditional dietary practices, and recognizing land-based activities as exercise have also proved important in the successful delivery of CR in Indigenous communities. This review summarizes the current evidence for culturally adapted CR programming for Indigenous patients, including strategies to engage communities in education on cardiovascular risk-factor optimization and to promote guideline-based exercise and diet through an Indigenous lens.

The Cardiovascular System in Heat Stroke.

In June 2021, western Canada experienced an unprecedented heat wave, breaking dozens of temperature records. As a result, the region had a significant uptick in sudden deaths, emergency department visits, and hospital admissions. Under thermal stress, the human body achieves heat dissipation through evaporation of sweat and increased cutaneous blood flow. When these mechanisms are overwhelmed, the core body temperature rises, which leads to heat stroke, a life-threatening syndrome of hyperthermia and central nervous system dysfunction in the setting of an environmental thermal load. Heat dissipation relies on an intact cardiovascular system to dilate cutaneous vasculature and increase cardiac output. Individuals with impaired cardiovascular function have a limited ability to increase stroke volume, cardiac output, and blood flow to the skin, increasing the risk of heat stroke. In turn, these patients, whose cardiac condition is already compromised, are susceptible to cardiovascular complications of heat stroke, including arrhythmias, myocardial ischemia, heart failure, shock, and sudden death. Indeed, the majority of excess deaths during heat waves are cardiovascular in origin, highlighting the impact the cardiovascular system has on the development of heat stroke, and vice versa. This review summarizes the current understanding of the interaction between the cardiovascular system and heat stroke, including the pathophysiology, cardiovascular complications, and treatment.

En juin 2021, l'Ouest canadien a connu une vague de chaleur sans précédent, au cours de laquelle des dizaines de records de température ont été battus. La région a de ce fait connu une augmentation significative des morts subites, des consultations aux urgences et des hospitalisations. En cas de stress thermique, le corps humain dissipe la chaleur par l'évaporation de la sueur et l'augmentation du flux sanguin cutané. Lorsque ces mécanismes sont dépassés, la température corporelle centrale augmente ce qui entraîne un coup de chaleur, un syndrome potentiellement mortel associant une hyperthermie et une dysfonction du système nerveux central dans un contexte de charge thermique exogène. La dissipation de la chaleur repose sur la dilatation des vaisseaux sanguins cutanés et l'augmentation du débit cardiaque qui sont possibles lorsque le système cardiovasculaire est intact. Chez les personnes atteintes d'insuffisance cardiovasculaire, la capacité à augmenter le volume d'éjection, le débit cardiaque et le flux sanguin vers la peau est limitée, ce qui augmente le risque de coup de chaleur. Ainsi, ces patients dont la santé cardiaque est déjà compromise sont sensibles aux complications cardiovasculaires du coup de chaleur, dont les arythmies, l'ischémie myocardique, l'insuffisance cardiaque, l'état de choc et la mort subite. En effet, la surmortalité observée durant les vagues de chaleur est principalement d'origine cardiovasculaire, ce qui met en lumière l'effet du système cardiovasculaire sur la survenue des coups de chaleur, et vice versa. Le présent article résume la compréhension actuelle de l'interaction entre le système cardiovasculaire et le coup de chaleur, notamment pour ce qui est de la physiopathologie, des complications cardiovasculaires et des traitements.

Patient Perspectives Regarding Genetic Testing for Familial Hypercholesterolemia.

BACKGROUND: Familial hypercholesterolemia (FH) is a common genetic disorder resulting in high levels of low-density lipoprotein cholesterol and increased risk of atherosclerotic cardiovascular disease. Genetic testing for FH is recommended but is not available in most of Canada. Consequently, there is a paucity of data regarding patient experiences with genetic testing. The objectives of this study were to investigate the attitudes and perspectives of patients with FH who underwent genetic testing. METHODS: We administered an anonymous online survey to participants in the British Columbia Familial Hypercholesterolemia Registry who had undergone research-based genetic testing for FH. The survey included 25 questions and explored patients' experiences with the genetic testing process, willingness to recommend genetic screening, and motivation to lower cholesterol levels. RESULTS: Among 183 respondents, 38 (20.7%) had a positive genetic test result, 27 (14.8%) had a negative result, and 118 (64.4%) were awaiting their results. Compared with individuals awaiting their test results, participants with a positive genetic test were more likely to believe lipid-lowering therapy was highly important (74.3% vs 55.4%; P = 0.05). They were also more likely to strongly agree that a diagnosis of FH was important to them (71.1% vs 46.2%; P = 0.008), and were more likely to recommend genetic screening to their family members (85.9% vs 72.9%; P = 0.04). CONCLUSIONS: To our knowledge, this is the first study in Canada to explore the perspectives of patients with FH who underwent genetic testing. These results suggest that genetic testing for FH might offer benefits in important patient-centred outcomes.

INTRODUCTION: L'hypercholestérolémie familiale (HF) est une maladie génétique fréquente qui entraîne des concentrations élevées de cholestérol à lipoprotéines de faible densité et un risque accru de maladies cardiovasculaires athérosclérotiques. L'analyse génétique de l'HF est recommandée, mais n'est pas disponible dans la plupart des régions du Canada. Par conséquent, il existe peu de données sur les expériences des patients ayant subi une analyse génétique. Les objectifs de la présente étude étaient d'enquêter sur les attitudes et les points de vue des patients atteints d'HF qui avaient subi une analyse génétique. MÉTHODES: Nous avons administré une enquête anonyme en ligne aux participants inscrits dans le registre British Columbia Familial Hypercholesterolemia qui avaient subi une analyse génétique fondée sur la recherche pour l'HF. L'enquête comptait 25 questions et portait sur les expériences des patients sur le processus d'analyse génétique, la volonté de recommander le dépistage génétique et la motivation à abaisser les concentrations de cholestérol. RÉSULTATS: Parmi les 183 répondants, 38 (20,7 %) avaient des résultats positifs à l'analyse génétique, 27 (14,8 %) avaient des résultats négatifs et 118 (64,4 %) attendaient leurs résultats. Comparativement aux individus qui attendaient leurs résultats d'analyse, les participants qui avaient des résultats positifs à l'analyse génétique étaient plus susceptibles de penser que le traitement hypolipémiant était très important (74,3 % vs 55,4 %; P = 0,05). Ils étaient aussi plus susceptibles d'être tout à fait d'accord sur le fait que le diagnostic d'HF était important pour eux (71,1 % vs 46,2 %; P = 0,008) et de recommander le dépistage génétique aux membres de leur famille (85,9 % vs 72,9 %; P = 0,04). CONCLUSIONS: À notre connaissance, au Canada, c'est la première étude sur les points de vue des patients atteints d'HF qui avaient subi une analyse génétique. Ces résultats indiquent que le dépistage génétique de l'HF pourrait favoriser des résultats importants axés sur le patient.

The Assessment and Sustainable Management of Sickle Cell Disease in the Indigenous Tharu Population of Nepal.

Sickle cell disease is an inherited hemoglobinopathy associated with significant morbidity and mortality. Reports suggest a high sickle cell disease burden among the indigenous Tharu population of Nepal, who for centuries have inhabited regions where malaria is endemic. Unfortunately, health care resources are limited and often inaccessible for Tharu individuals suffering from sickle cell disease. We conducted a large-scale screening effort to estimate the prevalence of Hb S (HBB: c.20A>T) among the Tharu population and delivered community-based education sessions to increase sickle cell disease awareness. A total of 2899 Tharu individuals aged 6 months to 40 years in the rural district of Dang in Western Nepal were screened using a sickling test, of whom, 271 [9.3%; 95% confidence interval (95% CI): 8.3-10.4%] screened positive for Hb S. Those who screened positive were offered diagnostic gel electrophoresis testing. Of the 133 individuals who underwent diagnostic testing, 75.9% (n = 101) were confirmed to be Hb AS heterozygotes, 4.5% (n = 6) were confirmed to be Hb SS homozygotes and 19.5% (n = 26) were false positives. These findings support a large burden of sickle cell disease among the Tharu population and highlight the importance of appropriate resource allocation and management. With a positive predictive value of 80.0% (95% CI: 73.0-87.0%), the sickling test in conjunction with raising local sickle cell disease awareness may be a simple and sustainable way to promote access to health resources.