Logistic Time Constant of Isovolumic Relaxation Pressure–
Time Curve in the Canine Left Ventricle
by Hiromi Matsubara, Miyako Takaki, Shingo Yasuhara, Junichi Araki, and Hiroyuki
Suga
Circulation
Volume 92(8):2318-2326
October 15, 1995
Copyright © American Heart Association, Inc. All rights reserved.
Schematic of pressure–time [P(t)] curves (A and E), semilogarithmic curves of P(t)−PB and P∞ (B
and F, respectively), dP/dt curves (C and G), and dP/dt–P(t) phase–plane curves (D and H) by the
logistic (A through D) and monoexponential (E through H) models.
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.
Plots of LV pressure [P(t)] (A and C) and residual (observed minus model) plots of the logistic
(B) or monoexponential model (D) during isovolumic relaxation obtained from a representative
isovolumic beat.
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.
Plots of dP/dt vs time (A and C) and dP/dt vs instantaneous LV pressure [P(t)] (phase–plane
diagram; B and D) during isovolumic relaxation obtained from the same beat shown in Fig 2. ○
shows observed data points measured every 2 ms; each solid line shows theoretically
calculated curve using the logistic (A and B) or monoexponential (C and D) models.
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.
Plots showing the relations of logistic time constant (TL) and exponential time constant (TE) to
EDP (A), heart rate (B), and EF (C).
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.
Representative plots of observed dP/dt vs instantaneous LV P(t) (phase–plane diagram) obtained
from the same beat demonstrated in Fig 2.
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.
Plot showing the summarized relations of the logistic time constant (TL) and exponential time
constant (TE) (y axis) and three different cutoff points (EDP+0, EDP+5, and EDP+10; x axis) in 14
isovolumic contractions (mean±SD).
Hiromi Matsubara et al. Circulation. 1995;92:2318-2326
Copyright © American Heart Association, Inc. All rights reserved.