Abstract
The mean left ventricular pressure-flow relationship (Pv-Fv), determined under a constant preload and variable peripheral resistance, has been proposed as a quantitative representation of ventricular pump function (9). We determined the Pv-Fv relation in seven isolated cross-perfused canine hearts by varying resistance of a simulated arterial load in five steps from 6.0 to 0.375 mmHg X s X ml-1 while keeping end-diastolic volume, inotropic state, compliance, and characteristic impedance at various constant values. All of the 27 Pv-Fv relations thus determined were moderately nonlinear. Varying end-diastolic volume at three levels shifted the relation curve in an approximately parallel fashion (P less than 0.0001). At three levels of inotropic state (mean LVP of isovolumic contractions 34.3 +/- 8.2, 48.0 +/- 6.3, and 59.2 +/- 9.6 mmHg), the Pv-Fv relation shifted with predominantly a slope change (P less than 0.0001). Changing compliance at three levels (0.2, 0.4, and 0.8 ml/mmHg) caused a statistically significant but quantitatively small crossover of the Pv-Fv curves (P less than 0.0001). Changing characteristic impedance to 0.1, 0.2, and 0.4 mmHg X s X ml-1 caused a highly significant (P less than 0.0001) divergence of Pv-Fv relation over the high Fv range. We conclude that this sensitivity of the Pv-Fv relation to characteristic impedance limits its use as a contractility index.
| Original language | English (US) |
|---|---|
| Journal | The American journal of physiology |
| Volume | 247 |
| Issue number | 6 Pt 2 |
| State | Published - Dec 1984 |
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Effects of arterial input impedance on mean ventricular pressure-flow relation. / Maughan, William L; Sunagawa, K.; Sagawa, K.
In: The American journal of physiology, Vol. 247, No. 6 Pt 2, 12.1984.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of arterial input impedance on mean ventricular pressure-flow relation.
AU - Maughan, William L
AU - Sunagawa, K.
AU - Sagawa, K.
PY - 1984/12
Y1 - 1984/12
N2 - The mean left ventricular pressure-flow relationship (Pv-Fv), determined under a constant preload and variable peripheral resistance, has been proposed as a quantitative representation of ventricular pump function (9). We determined the Pv-Fv relation in seven isolated cross-perfused canine hearts by varying resistance of a simulated arterial load in five steps from 6.0 to 0.375 mmHg X s X ml-1 while keeping end-diastolic volume, inotropic state, compliance, and characteristic impedance at various constant values. All of the 27 Pv-Fv relations thus determined were moderately nonlinear. Varying end-diastolic volume at three levels shifted the relation curve in an approximately parallel fashion (P less than 0.0001). At three levels of inotropic state (mean LVP of isovolumic contractions 34.3 +/- 8.2, 48.0 +/- 6.3, and 59.2 +/- 9.6 mmHg), the Pv-Fv relation shifted with predominantly a slope change (P less than 0.0001). Changing compliance at three levels (0.2, 0.4, and 0.8 ml/mmHg) caused a statistically significant but quantitatively small crossover of the Pv-Fv curves (P less than 0.0001). Changing characteristic impedance to 0.1, 0.2, and 0.4 mmHg X s X ml-1 caused a highly significant (P less than 0.0001) divergence of Pv-Fv relation over the high Fv range. We conclude that this sensitivity of the Pv-Fv relation to characteristic impedance limits its use as a contractility index.
AB - The mean left ventricular pressure-flow relationship (Pv-Fv), determined under a constant preload and variable peripheral resistance, has been proposed as a quantitative representation of ventricular pump function (9). We determined the Pv-Fv relation in seven isolated cross-perfused canine hearts by varying resistance of a simulated arterial load in five steps from 6.0 to 0.375 mmHg X s X ml-1 while keeping end-diastolic volume, inotropic state, compliance, and characteristic impedance at various constant values. All of the 27 Pv-Fv relations thus determined were moderately nonlinear. Varying end-diastolic volume at three levels shifted the relation curve in an approximately parallel fashion (P less than 0.0001). At three levels of inotropic state (mean LVP of isovolumic contractions 34.3 +/- 8.2, 48.0 +/- 6.3, and 59.2 +/- 9.6 mmHg), the Pv-Fv relation shifted with predominantly a slope change (P less than 0.0001). Changing compliance at three levels (0.2, 0.4, and 0.8 ml/mmHg) caused a statistically significant but quantitatively small crossover of the Pv-Fv curves (P less than 0.0001). Changing characteristic impedance to 0.1, 0.2, and 0.4 mmHg X s X ml-1 caused a highly significant (P less than 0.0001) divergence of Pv-Fv relation over the high Fv range. We conclude that this sensitivity of the Pv-Fv relation to characteristic impedance limits its use as a contractility index.
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UR - http://www.scopus.com/inward/citedby.url?scp=0021665557&partnerID=8YFLogxK
M3 - Article
C2 - 6507645
AN - SCOPUS:0021665557
VL - 247
JO - American Journal of Physiology
JF - American Journal of Physiology
SN - 0363-6135
IS - 6 Pt 2
ER -