Title:Forward and Backward Aortic Components and Reflection Indexes in Children and Adolescents: Determinants and Role in High Pressure States
VOLUME: 14 ISSUE: 2
Author(s):Yanina Zocalo*, Juan M. Castro, Victoria Garcia-Espinosa, Santiago Curcio, Pedro Chiesa, Gustavo Giachetto, Edmundo I. Cabrera-Fischer and Daniel Bia
Affiliation:Physiology Department, Faculty of Medicine, Centro Universitario de Investigacion, Innovacion y Diagnostico Arterial (CUiiDARTE), Republic University, Montevideo, Physiology Department, Faculty of Medicine, Centro Universitario de Investigacion, Innovacion y Diagnostico Arterial (CUiiDARTE), Republic University, Montevideo, Physiology Department, Faculty of Medicine, Centro Universitario de Investigacion, Innovacion y Diagnostico Arterial (CUiiDARTE), Republic University, Montevideo, Physiology Department, Faculty of Medicine, Centro Universitario de Investigacion, Innovacion y Diagnostico Arterial (CUiiDARTE), Republic University, Montevideo, Servicio de Cardiologia Pediatrica, Centro Hospitalario Pereira Rossell, ASSE-Ministry of Public Health, Montevideo, Clinica Pediatrica , Instituto de Medicina Traslacional, Trasplante y Bioingenieria- IMTTyB, Favaloro University, CONICET, Buenos Aires, Physiology Department, Faculty of Medicine, Centro Universitario de Investigacion, Innovacion y Diagnostico Arterial (CUiiDARTE), Republic University, Montevideo
Keywords:Aortic wave reflections, arterial hypertension, blood pressure, central aortic blood pressure, children, Heart rate (HR).
Abstract:Background: High blood pressure states (HBP) would differ in wave components and
reflections indexes, which could associate clinical and prognostic implications. The study aims: 1)
to characterize the association of aortic wave components and reflection parameters (backward
[Pb], forward [Pf], Pb/Pf ratio and augmentation index [AIx]) with demographic, anthropometric,
hemodynamic and arterial parameters in healthy children and adolescents; 2) to generate multivariate
prediction models for the associations, to contribute to understand the main determinants of Pf,
Pb, Pb/Pf and AIx; 3) to identify if differences in wave reflection indexes observed in HBP could be
explained by differences in the analyzed parameters.
Methods: Healthy children and adolescents (n=816, females: 386; Age: 3-20 years) were studied.
Evaluations: central aortic pressure and wave components (Pb, Pf, Pb/Pf and AIx determination
with SphygmoCor [SCOR] and Mobil-o-Graph [MOG]); anthropometric assessment; regional arterial
stiffness (carotid-femoral, carotid-radial pulse wave velocity [PWV] and PWV ratio); carotid
intima-media thickness; carotid and femoral distensbility; cardiac output; systemic vascular resistances
(SVR). Simple and multiple regression models were constructed to determine aortic wave
parameters; the main explanatory variables. Normotensive and HBP groups were compared. Differences
in wave reflection indexes were analyzed before and after controlling for explanatory variables.
Equivalences between SphygmoCor and Mobil-O-Graph data were assessed (correlation and
Bland-Altman analyses).
Results and Conclusion: There were systematic and proportional differences between the data obtained
with SphygmoCor and Mobil-O-Graph devices. Heart rate (HR), peripheral pulse pressure,
height and weight were the variables that isolated (simple associations) or combined (multiple associations),
showed the major capability to explain interindividual differences in Pf, Pb, Pb/Pf and
AIx. Arterial stiffness also showed explanatory capacity, being the carotid the artery with the major
contribution. HBP associated higher Pf, Pb, AIx and lower Pb/Pf ratio. Those findings were observed
together with higher weight, arterial stiffness and HR. After adjusting for anthropometric
characteristics, HR, cardiac output and SVR, the HBP group showed greater Pf and Pb. Then, Pf
and Pb characteristics associated with HBP would not be explained by anthropometric or hemodynamic
factors. Evaluating wave components and reflection parameters could contribute to improve
the comprehension and management of HBP states.
