### 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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### ASJC Scopus subject areas

- Medicine(all)

### Cite this

*The American journal of physiology*,

*247*(6 Pt 2).

**Effects of arterial input impedance on mean ventricular pressure-flow relation.** / Maughan, William L; Sunagawa, K.; Sagawa, K.

Research output: Contribution to journal › Article

*The American journal of physiology*, vol. 247, no. 6 Pt 2.

}

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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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 -