Five-year-old Zoey Kenison slips her feet onto the bike pedals and begins cycling, hands gripping the handle bars.
But this is no ordinary bike. It’s a pediatric cycle ergometer, a fixed stationary bike that measures her heart rate, blood pressure, electrocardiogram and breath-by-breath respiratory indices, including volumes and the exchange of oxygen and carbon dioxide.
Kenison has a rare and complex form of congenital heart disease called levo-transposition of the great arteries. The chambers within her heart are connected abnormally and the arteries leading the body and lungs are also connected abnormally. She has undergone one cardiac surgery and the timing for her next surgery is unclear since it is such a rare disease.
Changes seen by imaging of the heart or a change in her exercise tolerance provide further criteria for surgery. But how do you gauge a change in a small child’s exercise tolerance?
For Kenison, formal cardiopulmonary exercise testing with respiratory analysis and exercise echocardiography at the Pulmonary Function and Exercise Testing Lab at UC Davis is just what the doctor ordered.
This lab has become an increasingly integral part of patient diagnosis, prognosis and follow-up for pediatric and adult patients with congenital heart disease. The results of these stationary bike tests can provide an objective measure of exercise capacity, as well as potential causes of exercise limitation on the heart, lungs, muscle, metabolism or a combination of these. And thanks to a grant from the Children’s Miracle Network at UC Davis, the team has the ability to offer this kind of testing to children as young as five years of age.
Forty-five tests have been conducted since the lab opened in 2015, four of which were conducted on the new pediatric cycle ergometer. The results from these tests have been indispensable to the care of UC Davis patients, according to pediatric cardiologist Yoni Dayan.
For Kenison, her exercise capacity test results proved excellent and her surgery has been postponed for now. Additionally, a new baseline for Kenison has been established.
For more information about cardiopulmonary exercise testing, please contact the UC Davis Pulmonary Function and Exercise Testing Lab at 916-734-2657 or the UC Davis Pediatric Heart Center at 916-734-3456.