Innovative multi-site photoplethysmography measurement and analysis demonstrating increased arterial stiffness in paediatric heart transplant recipients
Objective: It has been documented that heart transplantation in children is often complicated by arterial hypertension and increased arterial stiffness. Aim: to use innovative multi-site photoplethysmography (MPPG) pulse measurement and analysis technology to assess arterial stiffness change in paediatric heart transplant recipients (HTR) in comparison with healthy control (HC) children. Approach: 20 heart transplant (median age 13.5 years old) (8 male) recipients were compared to an overall
... ed to an overall age-and gender-matched group of 161 healthy controls (11.6 years old) (74 male). The peripheral pulse was recorded bilaterally using MPPG at the ear lobe, index finger and great toe sites, along with an ECG cardiac timing reference. Segmental pulse arrival times between peripheral sites (finger-ear, PATf-e; toe-finger, PATt-f; toe-ear, PATt-e) were calculated as arterial stiffness measures, and differences between subject groups tested using multivariate analysis. Normalised ear, finger and toe pulse shapes were also studied and compared between groups. Main results: After correction for heart rate, and diastolic and mean blood pressures the HTR group was found to have significantly lower segmental PATt-e and PATt-f measures, with median values of 150 ms versus 172 ms in HC (p=0.02) and 104 ms (versus 118 ms in HC, p=0.01), respectively, and consistent with increased arterial stiffness in the patient group. The normalised ear, finger and toe sites showed only a mild elongation in each rise time for the transplant group. Significance: This study shows innovative and easy-to-do multi-site photoplethysmography gives further evidence for increased arterial stiffness in children who have undergone successful cardiac transplantation.