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Assessment of pulmonary arterial compliance evaluated using harmonic oscillator kinematics
Yasunobu Hayabuchi1, Akemi Ono1, Yukako Homma1
1Department of Pediatrics, Tokushima University, Tokushima, Japan.
Insights
A new parameter, KPA, derived from pulmonary artery pressure (PAP) profiles, shows promise in reflecting pulmonary artery (PA) compliance in pediatric patients. This novel measure demonstrates strong reliability and correlates with established methods for assessing PA compliance.
Area of Science:
- Cardiovascular Physiology
- Pediatric Cardiology
- Biomedical Engineering
Background:
- Pulmonary artery (PA) compliance is crucial for assessing cardiovascular health in pediatric patients.
- Current methods for measuring PA compliance can be complex and have limitations.
- A novel, reliable parameter is needed to quantify PA compliance in children.
Purpose of the Study:
- To investigate whether KPA, a parameter derived from harmonic oscillator kinematics of the pulmonary artery pressure (PAP) profile, reflects PA compliance in pediatric patients.
- To assess the correlation of KPA with conventional measures of PA compliance and resistance.
- To evaluate the reproducibility and preload independence of KPA.
Main Methods:
- A prospective study involving 33 pediatric patients with cardiac diseases.
- KPA was calculated using the equation KPA = (dP/dt_max)² / ([Pmax - Pmin]/2)², derived from the PAP profile.
- PA compliance was measured using systolic PA compliance (sPAC) and diastolic PA compliance (dPAC) via conventional methods.
- Data were collected during abdominal compression to assess preload influence.
Main Results:
- KPA showed a significant correlation with sPAC (r=0.52, P=0.0018) but not dPAC.
- KPA correlated significantly with the time constant (τ) of diastolic PAP (r=-0.51, P=0.0026) and pulmonary vascular resistance index (r=-0.39, P=0.0242).
- KPA demonstrated excellent intra-observer (0.998) and inter-observer (0.997) reproducibility, outperforming other parameters.
- No significant change in KPA was observed during abdominal compression, suggesting preload independence.
Conclusions:
- The novel parameter KPA shows significant correlation with established measures of PA compliance and resistance in pediatric patients.
- KPA offers a reliable and reproducible method for quantifying PA compliance, potentially aiding in the understanding of PA mechanics.
- KPA may serve as a valuable tool for clinical assessment and research in pediatric cardiovascular diseases.
Abstract:
We hypothesized that KPA, a harmonic oscillator kinematics-derived spring constant parameter of the pulmonary artery pressure (PAP) profile, reflects PA compliance in pediatric patients. In this prospective study of 33 children (age range = 0.5-20 years) with various cardiac diseases, we assessed the novel parameter designated as KPA calculated using the pressure phase plane and the equation KPA = (dP/dt_max)2/([Pmax - Pmin])/2)2, where dP/dt_max is the peak derivative of PAP, and Pmax - Pmin is the difference between the minimum and maximum PAP. PA compliance was also calculated using two conventional methods: systolic PA compliance (sPAC) was expressed as the stroke volume/Pmax - Pmin; and diastolic PA compliance (dPAC) was determined according to a two-element Windkessel model of PA diastolic pressure decay. In addition, data were recorded during abdominal compression to determine the influence of preload on KPA. A significant correlation was observed between KPA and sPAC (r = 0.52, P = 0.0018), but not dPAC. Significant correlations were also seen with the time constant (τ) of diastolic PAP (r = -0.51, P = 0.0026) and the pulmonary vascular resistance index (r = -0.39, P = 0.0242). No significant difference in KPA was seen between before and after abdominal compression. KPA had a higher intraclass correlation coefficient than other compliance and resistance parameters for both intra-observer and inter-observer variability (0.998 and 0.997, respectively). These results suggest that KPA can provide insight into the underlying mechanisms and facilitate the quantification of PA compliance.
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