Video games could get kids with heart disease moving

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: 1. aged 8-18 years, with a confirmed diagnosis of congenital heart disease and a history of cardiac surgery or catheter-based intervention; 2. at least 3 months since the most recent surgery or intervention, with a clinically stable condition and no planned reintervention in the near future; 3. deemed by a pediatric cardiologist to be suitable for regular physical activity or low-to-moderate to moderate-to-vigorous physical activity; 4. presenting with insufficient physical activity and/or impaired exercise capacity, defined by at least one of the following: failure to meet the recommended physical activity level for children and adolescents (ie, an average of 60 minutes of moderate-to-vigorous physical activity per day), objectively impaired exercise capacity (eg, peak oxygen uptake \<80% of predicted and/or anaerobic threshold \<55% of predicted), or reduced exercise tolerance indicated by the 6-minute walk test, physical fitness assessment, or clinical exercise evaluation; 5. having basic cognitive and communication abilities sufficient to understand instructions and complete questionnaires, trial sessions, and training tasks; 6. willingness of both the child and the guardian to participate, with written informed consent obtained; 7. availability of basic family conditions to support intervention delivery, including access to smart devices and/or game equipment, internet access, and at least one caregiver able to provide support. Exclusion Criteria: 1. clear contraindications to exercise, such as uncontrolled arrhythmia, overt heart failure, severe pulmonary hypertension, or recent hemodynamic instability; 2. severe comorbidities that substantially interfere with exercise performance, such as serious neurological disorders, severe musculoskeletal disorders, or other conditions markedly limiting physical activity; 3. participation within the previous 3 months in another systematic intervention likely to substantially influence physical activity or exercise capacity; 4. any condition, as comprehensively judged by the research team, that may affect participant safety, intervention implementation, the quality of physical activity monitoring data, or completion of questionnaires or follow-up, including refusal to wear the monitoring device, refusal to complete follow-up, or evident risk of poor adherence.