An electric circuit model successfully isolated reflected blood pressure waves, demonstrating shorter peak latency and higher amplitude in a 48-year-old male compared to three healthy young males.
Cross-Sectional (n=4)
No
A proposed two-element electric circuit model successfully isolated blood pressure reflected waves, demonstrating shorter latency and higher amplitude in a middle-aged subject compared to young subjects, consistent with age-related arterial stiffening.
n this study, an electric circuit model was used to isolate the reflected waves from the blood pressure waves recorded in a large artery. The flow waveform of the blood ejected from the left ventricle was recorded as a constant current source of an electric circuit model comprising electric capacity CA, corresponding to the aorta compliance, and electric resistance Rp, － 10 corresponding to the total peripheral resistance. This model is commonly referred to as a two‒element windkessel model. The parameters of the two elements varied in a way that the slope of up‒stroke of the output voltage waveform and one of the blood pressure waveform accord and that of the minimum output voltage and diastolic blood pressure accord at the same time. Because the reflected wave is not included in this output voltage waveform at this time, a waveform obtained by subtracting the voltage waveform from the assessed blood pressure waveform could be considered a reflected wave. The peak latency of the reflected wave calculated by this method from the blood pressure waveform recorded in a 48‒year‒old male was shorter than the one recorded in three healthy college students. In addition, the amplitudes of the reflected wave in the 48‒year‒old male were higher than the ones in these students. These results reflect the increase in the pulse wave velocity because of the decrease in the arterial compliance in middle‒aged male and the enhancement of the reflected wave because of the increase in the peripheral resistance of the arterial system of the head and neck. On the other hand, there was an example where a small negative component other than the main reflected wave component was detected.
Noritaka Okamura (Sun,) conducted a cross-sectional in Healthy (n=4). Electric circuit model simulation vs. Young vs middle-aged subjects was evaluated on Reflected wave latency and reflected wave rate. An electric circuit model successfully isolated reflected blood pressure waves, demonstrating shorter peak latency and higher amplitude in a 48-year-old male compared to three healthy young males.