What question did this study set out to answer?

To determine the direct influence of left ventricular diastolic pressure on diastolic coronary pressure-flow relationships independently of vascular capacitive flow.

March 1, 1984AJP Heart and Circulatory Physiology

Preload-induced alterations in capacitance-free diastolic pressure-flow relationship

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Population

Open-chest heart-blocked canine preparation with adenosine-vasodilated left circumflex bed

Comparison

Adjustment of left ventricular diastolic… vs Different levels of LVDP (preload)

Design

Preclinical

Authors

TAThomas AversanoJohns Hopkins University FKFrancis J. KlockeCardiac Imaging RMRobert E. MatesMircea cel Batran Naval Academy

Discussion

Member takes

Implication

Should not change clinical practice; leaves open whether preload modulates coronary conductance in patients.

Key Points

To determine the direct influence of left ventricular diastolic pressure on diastolic coronary pressure-flow relationships independently of vascular capacitive flow.
Utilized an open-chest, heart-blocked canine model with maximally vasodilated left circumflex coronary beds using adenosine.
Imposed sequential declining and rising coronary pressure ramps (2–40 mmHg/s) across arrested long diastoles while clamping left ventricular diastolic pressure at preset levels using an external reservoir.
Calculated capacitance-free pressure-flow relationships by averaging values midway between paired down- and up-ramp responses.
Capacitance-free diastolic pressure-flow curves displayed curvilinearity that progressively increased with rising preload.
Zero-flow pressure intercepts rose from 14 ± 1.1 mmHg to 23 ± 1.4 mmHg as preload increased from 6–10 mmHg to 31–35 mmHg.
Coronary conductance and diastolic coronary flow fell progressively as preload increased, with conductance reductions being most marked at higher preloads and lower coronary pressures.

Structured PICO

Population

Open-chest heart-blocked canine preparation with adenosine-vasodilated left circumflex bed

Intervention

Adjustment of left ventricular diastolic pressure (LVDP) to preselected levels

Comparator

Different levels of LVDP (preload)

Outcome

Capacitance-free diastolic pressure-flow relationship (pressure-axis intercepts, coronary conductance, diastolic coronary flow)surrogate

In a canine model, increasing left ventricular preload increases pressure-axis intercepts and decreases coronary conductance and diastolic coronary flow.

Cite This Study

Aversano et al. (1984) studied this question.

synapsesocial.com/papers/6a914d0749be6cf6a846641d https://doi.org/10.1152/ajpheart.1984.246.3.h410

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Preload-induced alterations in capacitance-free diastolic pressure-flow relationship

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Preload-induced alterations in capacitance-free diastolic pressure-flow relationship

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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