115 / 2017-09-08 13:46:40

Effects of central arterial pressure waveform morphology on transfer function-derived central arterial waveform characteristics

15782,15784,15786,15788

The generalized transfer functions are used to evaluate central pressure and relative index. In this study, we investigated the effects of central pressure waveform morphology on GTF, and quantified the errors in GTF-derived central arterial waveform characteristics. One hundred and nine subjects (51.9 ± 18.3 years) were included in the study and were divided into two groups (Group A: n=67, Group C: n=42) based on the shape of carotid pressure waveform. Carotid and radial pressure waveform were simultaneously measured by using applanation tonometry. Mean radial-to-carotid transfer function (TF) of the Group A, Group C and the whole group (GTF) were obtained by an autoregressive exogenous model. Central systolic blood pressure (cSBP), augmentation index (AIx) and other waveform parameters derived using generalized, morphology-appropriate, and morphology-inappropriate TFs were compared with their measured values. There were significant differences between groups in measured cSBP (P <0.01). The GTF-derived cSBP strongly correlated with the measured cSBP (r = 0.965, P <0.001; mean difference: 0.9 ± 3.9 mmHg). A morphology-specific TF slightly improved the estimation of cSBP, but not significantly (P <0.01). Significant differences were found between morphology-appropriate and generalized TF for most parameters in Group A (P <0.01). A morphology-specific TF significantly improved the derivation of AIx (P <0.01). Central arterial pressure can be accurately obtained from peripheral artery by a generalized transfer function. However, a morphology-appropriate transfer function may be more suitable for estimating morphology-dependent parameters such as AIx of central pressure waveform.