Kevin Harris

Background: Children with congenital heart disease (CHD) now have excellent survival into adulthood but have an increased risk of cardiovascular disease. One important strategy to mitigate this risk is through physical activity (PA) promotion. It is currently not known how to optimally improve PA in children with CHD. We aimed to determine the feasibility and acceptability of a theoretically based virtual PA counselling intervention for children and families with CHD and explore PA changes after the intervention. Methods: We designed a 12-week family-centered, individualized, virtual PA counselling intervention based on behaviour change theory. Children ages 9 to 12 with moderate-to-complex CHD were recruited from BC Children’s Hospital. At baseline, we measured participants’ moderate-to-vigorous PA using accelerometers and readiness to change their PA using a questionnaire to determine intervention eligibility. Participants who were not meeting the PA guidelines and expressed readiness to change qualified for the PA counselling intervention. The intervention consisted of 6 sessions with a PA counsellor via Zoom where participants learned strategies to promote PA through workbook activities. We measured PA again at the intervention midpoint, post-intervention, and one year follow-up. Intervention feasibility (recruitment, retention, completion of PA measures, remote delivery, session length, and time commitment) and acceptability (intervention compliance and participant feedback via interviews and surveys) were assessed. Results: Despite lower than anticipated recruitment rates, this intervention was feasible based on high retention, completion of PA measures, and remote delivery success. Participants were committed and engaged with the intervention as seen by excellent attendance and activity completion rates, and positive participant feedback via qualitative and quantitative measures. There were no significant differences in objective or subjective PA measures from pre-intervention to post-intervention but there were likely intervention responders and non-responders, and more data is needed to determine intervention sustainability. Conclusion: This PA counselling intervention is feasible and acceptable to families and children with CHD. All measures of acceptability encourage that the intervention is engaging and well received by children with CHD. Preliminary objective PA data suggests that the intervention may have facilitated increased PA for some participants.

View record

Background – As the survival rates of children with congenital heart disease (CHD) increase, they are at increased risk for secondary cardiovascular events. Aortic stiffening, an indicator of vascular dysfunction, is predictive of premature cardiovascular events and mortality. It has been demonstrated that children with moderate-to-severe CHD have elevated aortic stiffness compared to healthy age-matched controls. Physical activity (PA) is an important determinant of optimal vascular health. Cross-sectional studies have demonstrated the beneficial associations between PA and vascular function in children with CHD. To date, it is not known how aortic stiffness and levels of PA change over time. The longitudinal relationship between the two parameters has also not been evaluated.In order to facilitate effective PA counselling in a clinical setting for children with CHD, physicians need to be aware of the effects of seasonal variation on this heterogeneous behaviour. While seasonal variation has been extensively documented in the healthy pediatric population, there are no known data on the longitudinal PA patterns for children with CHD.Methods – Children (9 – 16 years old) with moderate or complex CHDs were recruited at BC Children’s Hospital as part of a prospective cohort study. Longitudinal changes for aortic stiffness and PA were assessed over 3 time-points over a ~24-months period during routine clinical care. Aortic stiffness was assessed using standard echocardiography and Doppler equipment, while PA was assessed using an accelerometer.Daily step counts were assessed continuously for 12-months via a commercial activity tracker (Fitbit Charge 2TM). PA levels were also assessed conventionally at one time-point via accelerometers and/or physical activity questionnaires (PAQ).Conclusions – We observed that aortic stiffness increases and PA decreases over time. Our longitudinal analysis suggested that there may be an inverse relationship between PA levels and aortic stiffness in children with CHD. We also demonstrated that PA levels change across seasons in children with CHD. It is important to be aware of this natural fluctuation when assessing and interpreting PA levels when using conventional methods and/or administering physical activity counselling.

View record

Congenital heart disease (CHD) encompasses a heterogenous group of lesions whereby the anatomic structures and relationships of the heart have not undergone a normal development. CHD is the most common congenital malformation in newborns, occurring in about 1% of live births. Over the last 5 decades improvements in surgical and interventional catheterization techniques have resulted in an average life expectancy well into adulthood. Three-dimensional (3D) modelling is capable of producing a physical 3D model from a digital clinical imaging data set. 3D printed cardiac models may be especially useful for the study and treatment of CHD as they can convey patient-specific information in 3D space. This research provides insights on the scope of use of patient specific 3D printed cardiac models used in the care of patients with CHD with respect to the available current body of literature and in clinical practice. This thesis investigates 1) reported uses of 3D printed CHD models in the literature; 2) access to and use of 3D printing technology for CHD in clinical practice; 3) applications of 3D printed CHD models for interventional cardiac procedural planning and 4) applications for undergraduate medical education.

View record