Dec. 13, 2023

Researchers tackling gap in knowledge about disorders of low blood pressure

Team awarded inaugural Michael and Terry Wilson Cardiovascular Innovation Research funding
doctor takes a man's blood pressure

Many people know that high blood pressure is linked with serious health problems, but they may not be aware that disorders of low blood pressure also cause devastating health effects.

Vasovagal syncope and postural orthostatic tachycardia syndrome (POTS) are common disorders of low blood pressure that cause debilitating symptoms such as light-headedness, brain fog, chronic fatigue and fainting.

Libin researchers Dr. Robert Sheldon, MD, and Dr. Satish Raj, MD, are world leaders in the investigation and treatment of these disorders. Dr. Raj has also led one of the largest studies looking at the growing number of long-COVID patients suffering with POTS-like symptoms.

Although there have been advanced in treating these conditions, there is a gap in knowledge about the mechanisms behind these disorders. It’s a problem Sheldon, Raj and a new collaborator, Dr. Antoine Dufour, PhD, are taking on with the goal of finding ways to better diagnose and treat patients with these disorders.

“This is important work because it will give us insight into possible abnormalities that we aren’t yet aware of,” says Raj. “It’s an opportunity to really understand what’s going on at a more fundamental level.”

The team is taking a biomedical approach. Leveraging Dufour’s expertise in identifying and analyzing proteins and enzymes found in blood plasma, they hope to identify cells that can identify the presence and type of low blood pressure disorders.

In the past few years, researchers have made huge advances that allow them to screen for these cells. Dufour’s lab has contributed further by developing a pipeline capable of analyzing huge quantities of data, making it possible to identify disease indicators and patterns that were previously like finding a needle in a haystack.  

Dufour explains that although around 8,000 proteins may be found in plasma, 20 proteins are responsible for more than 99 per cent of the volume. Identifying the other less than one per cent can be a huge challenge, yet it’s these cells that may contain the clues to what’s behind these disorders and how to treat them.

“It changes the game, allowing us to do analyses even at an individual patient level,” says Dufour, explaining this screening approach becomes very important if you aren’t sure what you are looking for, as is the case in this study.  

The team is excited about the possibilities of their work, and they already have the first group of participants for their study.

“This work will allow us to see patterns and unique differences in patients and hopefully provide the basis for our hypothesis that low blood pressure phenotypes can be defined by the proteins and enzymes that are found in the blood,” says Raj. “Ultimately, the goal is to find new targets, novel therapies and possible new uses for old drugs to help improve patient care.”

This project is funded by the Michael and Terry Wilson Cardiovascular Innovation Research Fund, a new grant that supports multi-investigator teams proposing collaborative, innovative and translational projects within the Libin Cardiovascular Institute. (

Satish Raj is a professor in the Department of Cardiac Sciences and a member of the Libin Cardiovascular Institute at the Cumming School of Medicine. He is education director at the Libin Cardiovascular Institute.

Dr. Antoine Dufour is an associate professor in the departments of Physiology & Pharmacology and Biochemistry and Molecular Biology at the University of Calgary. He is the scientific director of the University of Calgary Proteomics Core facility.