P6.11 EVALUATION OF A NOVEL AND EXISTING TECHNIQUES FOR THE ESTIMATION OF PULSE TRANSIT TIME

DOI

10.1016/j.artres.2013.10.192How to use a DOI?

Abstract

The method used for pulse transit time (PTT) estimation, affects critically the accuracy of pulse wave velocity (PWV) measurements. The existing methods for PTT estimation yield often substantially different PWV values. Since there is no analytical way to determine PTT in vivo, these methods cannot be validated except by using in silico or in vitro models of known PWV and PTT. We aimed to validate and compare the most commonly used “foot-to-foot” methods: “diastole-minimum”, “tangential”, “maximum 1st derivative” and “maximum 2nd derivative”. Also, we propose a new “diastole-patching” algorithm aiming to increase the accuracy and precision in PWV measurement. Methods: We simulated 2000 cases under a range of different hemodynamic conditions using a validated, distributed 1-D arterial model. The new algorithm “matches” a specific region of the pressure-wave foot between the proximal (i.e. carotid) and distal (i.e. femoral) waveforms. Intraclass correlation coefficient (ICC), mean difference (bias) and standard deviation of differences (SDD) were used to assess accuracy and precision. Results: The “ diastole-minimum” and the “ diastole-patching” methods showed an excellent agreement compared to the “real” PWV values of the model, as indicated by high values of ICC(>0.86).

Figure 1

Mean and standard deviation for the aortic PWV estimations of the 5 validated algorithms. Bar in black represents the “real” PWV of the model.

The “diastole patching” method resulted in low bias (0.26m/s). In contrast, PWV estimated by 1st or 2nd derivatives and the “tangential” method presented a low to moderate agreement and poor accuracy (ICC<0.79, bias>0.9 m/s). The “diastole-patching” method yielded PWV measurements with the highest agreement, accuracy, precision and the lowest variability and its validity remains to be further examined in vivo.

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TY  - JOUR
AU  - O.V. Vardoulis
AU  - T.G.P. Papaioannou
AU  - N.S. Stergiopulos
PY  - 2013
DA  - 2013/11/11
TI  - P6.11 EVALUATION OF A NOVEL AND EXISTING TECHNIQUES FOR THE ESTIMATION OF PULSE TRANSIT TIME
JO  - Artery Research
SP  - 156
EP  - 157
VL  - 7
IS  - 3-4
SN  - 1876-4401
UR  - https://doi.org/10.1016/j.artres.2013.10.192
DO  - 10.1016/j.artres.2013.10.192
ID  - Vardoulis2013
ER  -