Although heart rate and blood pressure readings from breath-holding tests are usually reliably accurate, another vital measurement could be missing a beat, a University of Alberta study shows.
Looking at whether a person’s heart and blood vessels react the same way every time they hold their breath while low on oxygen, researchers were surprised to discover that arrhythmias — irregular heartbeats — occurred only some of the time, which may make them harder to predict than previously assumed.
The findings provide a cautionary heads-up when interpreting irregular heartbeats for a person over time, says Craig Steinback, a professor in the Faculty of Kinesiology, Sport, and Recreation and member of the Women and Children’s Health Research Institute.
“This could be important for how scientists interpret lab results and how cardiovascular risk is assessed in a person,” he suggests.
“If you think about an average clinical workup on a patient, you might do a test and get an outcome, but that might not mean anything tomorrow, after a second test. Which result do you believe? What does that say about that person’s risk? So it could be important to not over-project in terms of those results.”
For the study, 16 healthy young adults, half male and half female, each held their breath four times a day for two days in a row. Each breath-hold lasted 39 seconds after breathing low-oxygen air for five minutes. The researchers tracked the participants’ heart rate, blood pressure and electrical heart activity for each session.
