Derivation of Pulse Wave Velocity from Arterial Waveforms in Children

Aortic stiffness can be measured using aortic pulse wave velocity (PWV), calculated from peripheral arterial waveforms. However, this method has not been validated in children. We sought to determine whether PWV could be feasibly measured by tonometry and accurately derived from the arterial waveforms available in critically ill infants and children. Applanation tonometry was used to measure brachio-femoral or carotid-femoral PWV (b/cfPWV) in hospitalized hemodynamically stable, pre-pubertal children with an indwelling arterial catheter. Peripheral arterial line waveforms were converted into ascending aortic waveforms by a model transfer function. We found that the effective reflecting distance (EfRD) calculation used in adults overestimated b/cfPWV in children. We derived a new EfRD equation that yielded a better agreement between measured and estimated PWV (R² = 0.30, p < 0.05). Estimating PWV from arterial waveforms data eliminates the need for tonometry, allowing larger sample sizes of infants and children to be included in future cardiovascular disease and development studies.