科研之友
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摘要
We hypothesized that K-PA, 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 K-PA calculated using the pressure phase plane and the equation K-PA = (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 K-PA. A significant correlation was observed between K-PA and sPAC (r =0.52, P =0.0018), but not dPAC. Significant correlations were also seen with the time constant (tau) 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 K-PA was seen between before and after abdominal compression. K-PA 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 K-PA can provide insight into the underlying mechanisms and facilitate the quantification of PA compliance.
- 出版日期2017-9
