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Systolic aortic pressure-time area is a useful index describing arterial wave properties in rats with diabetes.

Chang RW, Chang CY, Wu MS, Yu HY, Luo JM, Chen YS, Lin FY, Lai LC, Wang CH, Chang KC - Sci Rep (2015)

Bottom Line: The accurate measurement of arterial wave properties in terms of arterial wave transit time (τw) and wave reflection factor (Rf) requires simultaneous records of aortic pressure and flow signals.However, in clinical practice, it will be helpful to describe the pulsatile ventricular afterload using less-invasive parameters if possible.Arterial wave reflections were derived using the impulse response function of the filtered aortic input impedance spectra.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan.

ABSTRACT
The accurate measurement of arterial wave properties in terms of arterial wave transit time (τw) and wave reflection factor (Rf) requires simultaneous records of aortic pressure and flow signals. However, in clinical practice, it will be helpful to describe the pulsatile ventricular afterload using less-invasive parameters if possible. We investigated the possibility of systolic aortic pressure-time area (PTAs), calculated from the measured aortic pressure alone, acting as systolic workload imposed on the rat diabetic heart. Arterial wave reflections were derived using the impulse response function of the filtered aortic input impedance spectra. The cardiovascular condition in the rats with either type 1 or type 2 diabetes was characterized by (1) an elevation in PTAs; and (2) an increase in Rf and decrease in τw. We found that an inverse linear correlation between PTAs and arterial τw reached significance (τw = 38.5462 - 0.0022 × PTAs; r = 0.7708, P < 0.0001). By contrast, as the PTAs increased, the reflection intensity increased: Rf = -0.5439 + 0.0002 × PTAs; r = 0.8701; P <0 .0001. All these findings suggested that as diabetes stiffened aortas, the augmented aortic PTAs might act as a useful index describing the diabetes-related deterioration in systolic ventricular workload.

No MeSH data available.


Related in: MedlinePlus

The ascending aortic flow (A), pressure (B), and LV pressure (C) and the calculation of LV τe (D) in one normal rat. In (B), the red shaded area represents the aortic PTAs and the black line is the Pms. The start and end points of systole for PTAs calculation were identified as the intersection of 2 tangential lines around the foot of pressure waveform and that around the incisura caused by aortic valve closure, respectively. In (C), the red line represents the measured PLV and the green line is its derivative, i.e., dPLV/dt. In (D), the time course of LV isovolumic pressure decline is defined by the pressure point of the peak −dPLV/dt to 10 mmHg above the end-diastolic pressure. The LV τe was calculated as the negative inverse slope of the ln PLV versus t relationship. In this case, the LV τe was 8.84 ms with an r2 of 0.9980 and SEE of 0.42%. LV, left ventricular; PLV, LV pressure; Pms, mean systolic aortic pressure; PTAs, systolic aortic pressure-time area; r2, coefficient of determination; SEE, relative standard error of the estimate; τe, time constant of the LV isovolumic pressure decay.
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f1: The ascending aortic flow (A), pressure (B), and LV pressure (C) and the calculation of LV τe (D) in one normal rat. In (B), the red shaded area represents the aortic PTAs and the black line is the Pms. The start and end points of systole for PTAs calculation were identified as the intersection of 2 tangential lines around the foot of pressure waveform and that around the incisura caused by aortic valve closure, respectively. In (C), the red line represents the measured PLV and the green line is its derivative, i.e., dPLV/dt. In (D), the time course of LV isovolumic pressure decline is defined by the pressure point of the peak −dPLV/dt to 10 mmHg above the end-diastolic pressure. The LV τe was calculated as the negative inverse slope of the ln PLV versus t relationship. In this case, the LV τe was 8.84 ms with an r2 of 0.9980 and SEE of 0.42%. LV, left ventricular; PLV, LV pressure; Pms, mean systolic aortic pressure; PTAs, systolic aortic pressure-time area; r2, coefficient of determination; SEE, relative standard error of the estimate; τe, time constant of the LV isovolumic pressure decay.

Mentions: Figure 1A,B show the measured ascending aortic flow and pressure waveforms, respectively. In Fig. 1B, the red shaded area represents the aortic PTAs and the black line is the mean systolic aortic pressure (Pms). Figure 1C,D illustrate the calculation of the LV τe. The LV τe is the inverse negative slope of the ln PLV versus time (t) relation (Fig. 1D); thus, LV τe represents the time required for the LV pressure to decrease from a given pressure to 37% thereof. In this case, the LV τe was 8.84 ms with an r2 (i.e., the coefficient of determination) of 0.9980 and an SEE (i.e., the relative standard error of the estimate) of 0.42%.


Systolic aortic pressure-time area is a useful index describing arterial wave properties in rats with diabetes.

Chang RW, Chang CY, Wu MS, Yu HY, Luo JM, Chen YS, Lin FY, Lai LC, Wang CH, Chang KC - Sci Rep (2015)

The ascending aortic flow (A), pressure (B), and LV pressure (C) and the calculation of LV τe (D) in one normal rat. In (B), the red shaded area represents the aortic PTAs and the black line is the Pms. The start and end points of systole for PTAs calculation were identified as the intersection of 2 tangential lines around the foot of pressure waveform and that around the incisura caused by aortic valve closure, respectively. In (C), the red line represents the measured PLV and the green line is its derivative, i.e., dPLV/dt. In (D), the time course of LV isovolumic pressure decline is defined by the pressure point of the peak −dPLV/dt to 10 mmHg above the end-diastolic pressure. The LV τe was calculated as the negative inverse slope of the ln PLV versus t relationship. In this case, the LV τe was 8.84 ms with an r2 of 0.9980 and SEE of 0.42%. LV, left ventricular; PLV, LV pressure; Pms, mean systolic aortic pressure; PTAs, systolic aortic pressure-time area; r2, coefficient of determination; SEE, relative standard error of the estimate; τe, time constant of the LV isovolumic pressure decay.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664900&req=5

f1: The ascending aortic flow (A), pressure (B), and LV pressure (C) and the calculation of LV τe (D) in one normal rat. In (B), the red shaded area represents the aortic PTAs and the black line is the Pms. The start and end points of systole for PTAs calculation were identified as the intersection of 2 tangential lines around the foot of pressure waveform and that around the incisura caused by aortic valve closure, respectively. In (C), the red line represents the measured PLV and the green line is its derivative, i.e., dPLV/dt. In (D), the time course of LV isovolumic pressure decline is defined by the pressure point of the peak −dPLV/dt to 10 mmHg above the end-diastolic pressure. The LV τe was calculated as the negative inverse slope of the ln PLV versus t relationship. In this case, the LV τe was 8.84 ms with an r2 of 0.9980 and SEE of 0.42%. LV, left ventricular; PLV, LV pressure; Pms, mean systolic aortic pressure; PTAs, systolic aortic pressure-time area; r2, coefficient of determination; SEE, relative standard error of the estimate; τe, time constant of the LV isovolumic pressure decay.
Mentions: Figure 1A,B show the measured ascending aortic flow and pressure waveforms, respectively. In Fig. 1B, the red shaded area represents the aortic PTAs and the black line is the mean systolic aortic pressure (Pms). Figure 1C,D illustrate the calculation of the LV τe. The LV τe is the inverse negative slope of the ln PLV versus time (t) relation (Fig. 1D); thus, LV τe represents the time required for the LV pressure to decrease from a given pressure to 37% thereof. In this case, the LV τe was 8.84 ms with an r2 (i.e., the coefficient of determination) of 0.9980 and an SEE (i.e., the relative standard error of the estimate) of 0.42%.

Bottom Line: The accurate measurement of arterial wave properties in terms of arterial wave transit time (τw) and wave reflection factor (Rf) requires simultaneous records of aortic pressure and flow signals.However, in clinical practice, it will be helpful to describe the pulsatile ventricular afterload using less-invasive parameters if possible.Arterial wave reflections were derived using the impulse response function of the filtered aortic input impedance spectra.

View Article: PubMed Central - PubMed

Affiliation: Department of Physiology, College of Medicine, National Taiwan University, Taipei, 100, Taiwan.

ABSTRACT
The accurate measurement of arterial wave properties in terms of arterial wave transit time (τw) and wave reflection factor (Rf) requires simultaneous records of aortic pressure and flow signals. However, in clinical practice, it will be helpful to describe the pulsatile ventricular afterload using less-invasive parameters if possible. We investigated the possibility of systolic aortic pressure-time area (PTAs), calculated from the measured aortic pressure alone, acting as systolic workload imposed on the rat diabetic heart. Arterial wave reflections were derived using the impulse response function of the filtered aortic input impedance spectra. The cardiovascular condition in the rats with either type 1 or type 2 diabetes was characterized by (1) an elevation in PTAs; and (2) an increase in Rf and decrease in τw. We found that an inverse linear correlation between PTAs and arterial τw reached significance (τw = 38.5462 - 0.0022 × PTAs; r = 0.7708, P < 0.0001). By contrast, as the PTAs increased, the reflection intensity increased: Rf = -0.5439 + 0.0002 × PTAs; r = 0.8701; P <0 .0001. All these findings suggested that as diabetes stiffened aortas, the augmented aortic PTAs might act as a useful index describing the diabetes-related deterioration in systolic ventricular workload.

No MeSH data available.


Related in: MedlinePlus