Derivation of Pulse Wave Velocity from Arterial Waveforms in Infants and 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 (R{superscript 2} = 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. NEW AND NOTEWORTHYOur study provides a method for non-invasively measuring PWV in children using arterial waveforms. We used gold-standard tonometry to measure brachio/carotid-femoral PWV and derived an equation to estimate effective reflecting distance (EfRD) and PWV from the arterial waveforms in a pediatric critical care setting. We determined that PWV can be accurately estimated from arterial waveforms, providing a new tool for studying aortic stiffness in pediatric patients at risk for cardiovascular disease.