Heart Health & Research: Discovery of Electrical Conductivity Between Healthy and Damaged Heart Tissue
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The Dangers of Heart Disease and Efforts to Understand it
Heart disease is the second leading cause of death in Canada, and 2.4 million Canadians were affected by it in 2012—a number which is only increasing. The well-documented risk factors that increase the likelihood of encountering such illness are a familiar topic of discussion among Canadians. In North America, we live in a fast-paced, work-focused, and often stressful environment that causes a significant amount of anxiety; many of us cope with such a stressful environment by picking up harmful habits such as smoking, altering our lifestyle to accommodate our work schedule, or opting for processed fast foods in lieu of healthier homemade options—all of which have a detrimental effect on our health. Heart disease is a topic that many scientists and researchers are interested in, and are actively trying to understand. The ever-increasing database of evidence-based treatment, diagnosis and disease prevention is helping to save millions of lives all over the world. Recently, scientists at Stanford University discovered that a certain type of cells can be programmed to create new arteries that can redirect blood away from damaged or blocked arteries. In addition, technological advancements in 3D visualization and imaging has helped researchers and medical students develop a better understanding of the heart anatomy and function.
Exciting Research One Province Away
A few members of the Quinn group at Dalhousie. From left to right: Behzad Taeb, Matt Stoyek, Sara Rafferty, Alex Quinn, Breanne Cameron, Eilidh MacDonald
One of the researchers at the forefront of understanding the complex function of the human heart is Dr. Alex Quinn of Dalhousie University in Halifax, Nova Scotia. Dr. Quinn is an Assistant Professor at Dalhousie and is an expert in his field. After completing his Undergraduate degree at McGill University in Montreal, he went on to pursue his PhD at Columbia University and a Postdoctoral fellowship at Oxford University in England. During the various stages of his extensive studies, Dr. Quinn was always interested in understanding various aspects of the human heart—from blood flow and the heart’s mechanical process, to improving recovery time and treatments for heart disease patients. His research team, which consists of two graduate students, one postdoctoral fellow, one research technician and three undergraduate students, is particularly interested in understanding the underlying electro-mechanical processes of the heart at both the cellular and tissue level, and its connection to treatment of heart disease. In an interview with Dr. Quinn, he described that the heart is a mechanical pump that relies on electrical activity to do its job, and disruptions in those electrical activities can alter its mechanical process—which is the main topic of interest for Dr. Quinn’s team.
Discovery Implications and Future Research
One of the most dangerous conditions that a patient with heart disease may experience in their lifetime is a heart attack. Although heart attacks are manageable when emergency treatment is received in a timely manner, heart attacks can have many long-term effects on a patient’s heart—one of which is the formation of scar tissue. The damaged heart tissue was believed to actively block electrical activity and electrical connection in the heart but, in collaboration with researchers in the US, UK and Germany, Dr. Quinn and his team successfully demonstrated that scar tissues in the heart are able to conduct electricity and
Myocyte cells (red), which produce and conduct electricity in healthy tissue, and non-myocytes (green), which are found in damaged tissue, interspersed at the border of a scar.
A "tunneling nanotube", or nanoscopic connection between myocytes (blue) and non-myocytes (green).
form bridges with the healthy tissues. This observation was made using voltage-sensitive, fluorescent proteins. When those proteins, which were engineered to be expressed in scar tissue in a mouse’s heart, received electrical stimulation from the healthy tissue, they started to fluoresce and their activity was detected by Dr. Quinn and his team. The importance of this discovery lies in the fact that the failure of scar tissue to connect to healthy tissues is one of the causes of arrhythmia, a potentially life-threatening disorder in the heart’s beating rhythm. The discovery of this electrical conduction opens the door to great possibilities in post-heart attack treatment, and turns our understanding of the heart’s electric activity on its head since scar tissue was always believed to block an electric current. Utilizing this discovery in creating new treatment methods is something that Dr. Quinn and his team know is a long way off, but they are confident in the importance of this discovery and believe it can have amazing applications. The next steps for the team at Dalhousie is to figure out exactly how the tissues connect in order to teach scar tissue how to regain conductivity, and help the heart regain its natural activity.
Authors
Ahmed Eldesoky
Ahmed is studying Chemistry at the University of New Brunswick. He is interested in applications of chemistry in the energy sector--including Lithium-ion batteries, electrode materials, secondary energy devices and grid storage, and recently had the opportunity to work in Lithium-ion battery research at Dalhousie University in the first ever Tesla-sponsored university research lab. After his undergraduate degree, he hopes to join the renewable energy sector then later pursue graduate work in the field.
Researcher
Dr. Alexander Quinn
Dr. Quinn has reviewed this article for accuracy prior to its publication. If you would like to contact Dr. Quinn about his research, you can find more information on contacting him Here.
References
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[4] <img src=’//sgec stanford edu/content/dam/sm-news/images/2014/08/vaughn-90 jpg img 620 high png’ alt=’Christopher Vaughan’> By Christopher Vaughan Christopher Vaughan is the communications manager for the Stanford Institute for Stem Cell Biology and Regenerative Medicine Email him at vaughan1@stanford.edu, “Precursor cells discovered that could help regrow heart arteries,” News Center. [Online]. Available: http://med.stanford.edu/news/all-news/2015/10/precursor-cells-discovered-that-could-help-regrow-heart-arteries.html.
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[8] “Dalhousie researcher’s discovery may lead to new heart treatments | Metro Halifax.” [Online]. Available: http://www.metronews.ca/news/halifax/2017/01/18/dal-researcher-discovery-may-lead-to-new-heart-treatments.html. [Accessed: 16-Nov-2017].
[9] T. A. Quinn, “Cardiac mechano-electric coupling: a role in regulating normal function of the heart?,” Cardiovasc. Res., vol. 108, no. 1, pp. 1–3, Oct. 2015.
[10] “Alexander Quinn,” Dalhousie University. [Online]. Available: https://medicine.dal.ca/departments/department-sites/physiology/our-people/our-faculty/alexander-quinn.html.