The potential of cuffless blood pressure (BP) monitoring in children and adolescents is unclear. Although measurement of pulse arrival time (PAT) underlies many cuffless BP technologies, the pulse propagation distance (L) (from heart to measurement location) varies significantly during childhood growth and is likely to confound the desired relationship between PAT and BP in population-based algorithms. This study investigated whether the newly proposed pulse arrival velocity (PAV) (PAV=L/PAT) holds potential for improved tracking of exercise-induced BP changes in children and adolescents.

In 38 included paediatric participants (aged 12.3±3.9 years) undergoing Bruce protocol exercise testing, regression and leave-one-out cross-validation analyses were used to assess performance of PAT and PAV for estimating exercise-induced BP changes. The results were contextualised to BP validation standards.

With exercise, systolic BP increases of 36.1±15.8 mmHg were estimated by PAT-based and PAV-based models, with errors of 0.0±9.1 and 0.0±7.6 mmHg, respectively; the latter falling within the Association for the Advancement of Medical Instrumentation (AAMI) criteria of 5±8 mmHg, with high correlation (r=0.87). Diastolic BP changes (12.1±9.7 mmHg) were also estimated by PAV within the AAMI criteria (0.0±7.0 mmHg) but with modest correlation (r=0.51). Including heart rate, age, sex, or height did not improve model performance. PAV outperformed baseline models for systolic but not diastolic BP.

PAV shows potential for systolic BP tracking during exercise in children and adolescents. By accounting for variability in propagation length, PAV may provide better results than PAT in cuffless BP technology.