Title: What Factors Influence VO2peak in Adolescents with Tetralogy of Fallot: A Multi-faceted Analysis
Supervisor: Dr. William Sheel
Committee members: Dr. David Wright, Dr. Kathryn Armstrong, Astrid De Souza
Abstract: Over the last two decades, advancements in surgical technique and medical care have significantly increased the survival rate of individuals with Tetralogy of Fallot (TOF). This shift has sparked a growing interest in the long-term physiological and psychological health of TOF patients. TOF is a complex congenital heart disease characterised by four cardiac lesions and is typically surgically corrected within the first six months. Despite the restoration of normal cardiac anatomy, TOF patients continue to face hemodynamic complications such as pulmonary regurgitation and right ventricular dysfunction. This leads to decreased cardiac output and reduced oxygen delivery to the body, ultimately decreasing exercise capacity. Clinically, peak oxygen consumption (VO2peak) is a significant prognostic measure and is an independent predictor of adverse cardiovascular events. Growing evidence reports that VO2peak is reduced in adult and pediatric TOF patients. However, the underlying causes of this have not been explored. Thus, this thesis aims to fill this gap. This thesis will be conducted in 2 parts.
Study 1 is a retrospective cross-sectional study exploring the relationship between perioperative, echocardiographic variables and sports participation on VO2peak in adolescents with TOF. Perioperative variables examined are as follows: the length of hospital stay, the number of postoperative complications and the need for re-intervention. Echocardiographic variables will measure left and right ventricular systolic function via left ventricular ejection fraction (LVEF) and tricuspid annular plane systolic excursion (TAPSE). Sports participation will be measured as days per week.
Study 2 is a prospective cross-sectional study examining the relationship between motor skills, parental participation in recreational activity and adolescent sports participation on VO2peak in adolescents with TOF. Motor skills will be measured with the Bruininks-Oseretsky Test of Motor Proficiency, 2nd Edition – Short Form. Parental participation in the recreational activity will be measured with the Global Physical Activity Questionnaire as days per week. Sports participation will be measured as days per week.
The findings from this study will not only enhance our understanding of the intricate factors influencing VO2peak in adolescents with TOF but also provide valuable insight for clinicians and healthcare workers. These insights can potentially inform optimal intervention strategies to increase VO2peak and, consequently, the long-term well-being of TOF patients.