Researcher investigates link between aging and arrhythmias

Problems with the heart’s electrical system are serious. Arrhythmias, such as atrial fibrillation (AF), can lead to symptoms like heart palpitations, light-headedness, chest pain and shortness of breath, and are linked to strokes, sudden cardiac arrest and death.

Postdoctoral scholar Dr. Lockhart Jamieson, PhD, is investigating the link between aging and arrhythmias, with the goal of determining innovative therapies to prevent serious arrhythmias in the elderly.

She recently received a prestigious 2023 Canadian Institutes of Health Research Postdoctoral Fellowship to support her efforts. Jamieson is one of 16 UCalgary postdocs to receive CIHR Postdoctoral Fellowships this year.

“I am honoured that my work has been recognized,” says Jamieson. “This scholarship provides essential support needed for innovative and impactful research.”

Love for science starts young

Jamieson’s interest in science began at an early age. Like many youth in the early 2000s, she loved detective shows like CSI and initially wanted to become a forensic scientist. For that reason, Jamieson enrolled in the biomedical toxicology program at the University of Toronto, where she earned her undergraduate degree.

Following completion of her first degree, Jamieson returned home to Edmonton where she began working in the lab of Dr. John Seubert at the University of Alberta, following an earlier summer studentship in his lab.

That experience cemented her love of heart research. Ultimately, Jamieson decided to pursue a career in translational health, although she still holds a love for forensics and law. In 2020, she completed her PhD in pharmaceutical science at the University of Alberta’s Faculty of Pharmacy and Pharmaceutical Science.

Her PhD project looked at the impact of aging on mitochondria, small cellular structures that are essential regulators of energy production, inflammation and calcium signalling — all key to allowing the heart to beat properly.

Mitochondria essential to healthy aging

That work found that targeting mitochondrial function during aging with drug therapies may improve heart function for elderly individuals experiencing heart attacks.

“Mitochondria are involved in so many critical processes, they really are essential to healthy aging and a healthy heart.” Jamieson explains, “I just think they’re neat.”

After completing her PhD, Jamieson continued her studies in the lab of researcher Dr. Robert Rose, PhD, deputy director of the Libin Cardiovascular Institute. She brought her passion for understanding how aging impacts heart disease with her.

Her current project looks at how restricting calories impacts aging and frailty, a measure of an individual’s health status separate from their chronological age and how this correlates to arrhythmias.

Heart function decline differs in individuals

Jamieson explains that aging is known to be a major risk factor for serious arrhythmias, but the mechanisms behind this aren’t well understood. Additionally, some individuals age more successfully, with fewer declines in heart function, but scientists don’t why. Caloric restriction is known to have an impact on lifespan and mitochondrial health, but the connections to frailty and arrhythmias in aging is not understood.

Bringing all these concepts together, Jamieson’s goal is to find proteins that can be targeted in future drug design to prevent serious arrhythmias for aging individuals without the need for dietary changes.

“The clinical relevance is potentially vast, because aging changes everything, including treatment options,” says Jamieson. “Finding targets to reduce or even prevent severe arrhythmias has huge potential to improve quality of life for a very vulnerable population.”

The concept of improving quality of life for the elderly strikes a personal note for Jamieson, “My grandmother was diagnosed with dementia a few years ago,” she explains, “But what was most difficult was when she had to move into a long-term care facility.

“The independence of living on your own is a very important indicator of high quality of life to most people. Even though I’m a heart researcher, that experience solidified aging as the field I want to be in.

“I want to help others age with health, not just live for a long time.”

Jamieson’s career goals now lie in continuing her career in basic research, preferably with an emphasis on drug development.

“The lab is my happy place — planning and undertaking research projects is my favourite part of being a scientist,” she says. “Ultimately, my goal is to use my expertise in pharmacology to improve human health through innovative drug design. Seeing my work one day translated into the pharmacy would be very rewarding.”

Critical area of study

Rose says Jamieson’s work is important.

“Our population of aged individuals continues to grow, which means aging-related arrhythmias are increasing in prevalence. This a major challenge that requires innovative new research. Dr. Jamieson’s work is addressing this challenge by incorporating the assessment of frailty and how it can be modified to better understand arrhythmias in elderly individuals. This work has the potential to make a major impact in this critical area of study.”

He adds that the prestigious CIHR fellowship is well deserved and important in allowing Jamieson to continue her work.

“I am proud of Lockhart for her hard work and academic excellence,” he says. “We are grateful for CIHR’s support of this project.”

UCalgary’s CIHR Postdoctoral Fellowship recipients are:

• Dr. Nicholas W. Bray, PhD; Cumming School of Medicine (CSM): “Sex Matters: Probing the Relationship Between Frailty and Cerebrovascular Health in Adults at Risk of Alzheimer Disease and Related Dementias (ADRD)” (Supervisor: Dr. Marc Poulin, PhD and Dr. Bruce Pike, PhD)
• Dr. Zahra Clayborne, PhD; CSM: “From Languishing to Flourishing: A Mixed-Methods Approach to Operationalizing Maternal and Child Complete Mental Health and Associated Risk and Resiliency Factors” (Dr. Suzanne Tough, PhD and Dr. Sheila McDonald, PhD)
• Dr. Julie Deleemans, PhD; CSM: “The Chemo-Gut Trial: A Double-Blind Randomized Controlled Trial Investigating the Effects of a Multi-Strain Probiotic on Gut Microbiota, Gastrointestinal Symptoms, and Psychosocial Health in Cancer Survivors” (Dr. Linda Carlson, PhD)
• Dr. Erika Harding, PhD; Faculty of Veterinary Medicine: “Defining a Ventrolateral Periaqueductal Gray Brainstem Circuit Involved in Descending Modulation of Pain” (Dr. Tuan Trang, PhD and Dr. Gerald Zamponi, PhD)
• Dr. Craig Jacobs, PhD; CSM: “A Microevolutionary Model to Uncover the Developmental Basis Behind Phenotypic Variation in Structural Birth Defects” (Dr. Benedikt Hallgrimsson, PhD)
• Dr. Lockhart Jamieson, PhD; CSM: “Caloric Restriction Attenuates Sinoatrial Node Dysfunction and Atrial Fibrillation in Aged and Frail Mice” (Dr. Robert Rose, PhD)
• Dr. Ellen T. Koch, PhD; CSM: “Investigating Motor Learning and its Neural Basis in Stroke” (Dr. Tyler Cluff, PhD)
• Dr. Kathryn Y. Manning, PhD; CSM: “Treated and Untreated Prenatal Depression and the Relationship with Developing Infant Behaviour, Brain Structure, and Functional Connectivity Throughout the First Year of Life” (Dr. Catherine Lebel, PhD)
• Dr. Marina Rincon Sartori, PhD; CSM: “Investigating a Mechanistic Role for Mitochondria in Novel Cardiorespiratory Spinal Oxygen Sensor (SOS)” (Dr. Richard Wilson, PhD)
• Dr. Li Shu, PhD; CSM: “Unravelling the Complex Genetic Mechanisms of Rare Diseases Using High-Throughput Sequencing Methods” (Dr. Maja Tarailo-Graovac, PhD)
• Dr. Anastasiia Stepanchuk; PhD; CSM: “Strain-Typing of Alzheimer's Amyloid Using Advanced Fluorescence Spectroscopy” (Dr. Peter Stys, MD)
• Dr. Perri Tutelman, PhD; CSM: “A Transdiagnostic eHealth Intervention to Address Late Effects in AYA Survivors of Childhood Cancer” (Dr. Fiona Schlute, PhD)
• Dr. Elnaz Vaghef Mehrabani, PhD; CSM: “The Impact of Maternal Diet Pre-Pregnancy and During Gestation on Early Childhood Behavioral Problems” (Dr. Gerald Giesbrecht, PhD)
• Dr. Guosong Wu, PhD, MD; CSM: “The Development of Machine Learning Algorithms to Identify Perioperative Adverse Events Using Real-World Data” (Dr. Tyler Williamson, PhD)