Supplemental Material
Hemodynamic Simulator Results
Table S1 lists the calculated values of ejection volume and SVR with respect to ejection
time. As shown in the table, ejection volume, SVR, MAP, and aortic flow rate do not
change with varying ejection time in the hemodynamic simulator. The small changes in
calculated ejection volume were caused by small mean aortic flow variations.
Table S1 Hemodynamic measured values are maintained within the clinical range
Ejection
Time [ms]
Ejection
Volume*
[ml]
SVR* [mmHg
·min/L]
SBP/DBP/MAP
[mmHg]
Venous
MAP
[mmHg]
Mean Aortic
Flow [LPM]
434
66.1
15.4
117/60/82
22
3.9
382
67.8
15.7
131/56/86
23
4.0
326
66.1
15.9
136/53/85
23
3.9
297
66.9
15.4
139/51/85
24
3.9
252
66.8
15.5
142/49/85
24
3.9
*Calculated Value
Values maintained within a clinical range using the cardiovascular hemodynamic simulator. Changes in
ejection volume were caused by aortic flow variation. Clinical range for LVET (150-450)16; Ejection
Volume (55-100 ml)16; SVR (9-20 mmHg·min/L)17; SBP (90-180)16; DBP (40-110)16; Mean Aortic Flow (47)16.Values are expressed as mean (standard deviation) over each 60-second interval. For all measures
of ejection time, pressure and flow the standard deviation were below 1.3 ms, 0.1 mmHg, 0.02 LPM
respectively.
The mean and standard deviation for both MAP and SVR are 84.1, ±1.4 mmHg
and 15.4, ±0.25
respectively, which confirms that both remained nearly
constant across the range of ejection times tested. While the MAP remained
approximately constant the SBP increased by 25 mmHg and the DBP decreased by
approximately 11 mmHg as a function of LVET decreasing.
As can be seen in Table S1 across the range of ejection times, the associated
DBP changed from approximately 60-49 mmHg, for a constant SVR and MAP. In our
experiment, no adjustments were made across the five steps of decreasing ejection
time. Since the ejection time decreased while heart rate and ejection volume remained
constant, the time spent in diastole increased and thus resulted in a decreasing DBP.
The opposite effect is observed for SBP, which increases from 117-144 mmHg as
ejection time decreases. The observed changes for both SBP and DBP are consistent
with those observed clinically with changes in ejection time,16 but are on the low side of
clinical relevance. Increases in flow rate would have further increased the effect on
PWV as can be seen by equation (16).
Elastance Contour Plot
Figure S1 Elastance contour plot for fixed ejection volume (66 ml) and peak pressure (140 mmHg). The
model calculated a 1.04 MPa elastic modulus based on the measured peak pressure, ejection time and
PWV. The three annotated red diamonds are the model results using measurements taken at ejection
times (252, 297, 326). Each of these ejection times had a measured peak pressure of ~140 mmHg.
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Comparison of Model to Extracted Clinical Data
Figure S2. Extracted clinical data (squares)16 of PWV vs intra-arterial blood pressure for a 19-year-old
female (left) and a 58-year-old female (right) obtained during surgery.Sweeping the model across the
range of possible ejection times and volumes (Table S1 footnote) results in the gray region. The solid line
represents the best-fit pressure PWV curve for each patient.
To compare the model to the extracted clinical data (19 year old female, Figure
S2 left; and 58 year old female, Figure S2 right), cMK was estimated from the zero
crossing of an extension of the fitting curve presented in Ref. [7]; cMK was ~4.8 m/s and
~5.2 m/s for S2 left and right, respectively. The radii for the 19 year old and 58 year old
patient were selected based on age as 12.2 mm and 15 mm respectively.26 The wall
thickness and blood density were kept constant at2.0 mm and 1025kg/m 3 respectively.26
Using these values we calculated the resulting E0 using equation (11). The per-patient
constant ‘a’ was adjusted to closely fit the individual’s PWV versus pressure response,
which is likely dominated by the dynamic elasticity of the aorta. In both cases, the
altered variables were maintained within the clinical range.16,17 Since ejection volume
and time were not measured in the referenced study, the PWV versus pressure
relationship was estimated based on the ranges identified in the footnote of Table S1.
Differences in flow velocity (as determined from ejection time and volume) potentially
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account for the measured scatter in the PWV versus pressure data points. The model
demonstrates the correct curvature, and the expected range (gray) based on flow
velocity encompasses most of the measured data points. Data points outside of the
expected range could be due to surgically induced changes in ejection time and volume
beyond the range assumed for healthy individuals.
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