What question did this study set out to answer?

To determine whether the oxygen cost of left ventricular contractility depends on heart rate in blood-perfused excised rat hearts.

January 1, 2001The Japanese Journal of PhysiologyOpen Access

No Dependency of a New Index for Oxygen Cost of Left Ventricular Contractility on Heart Rates in the Blood-Perfused Excised Rat Heart.

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Population

12 excised, cross-circulated rat heart preparations from retired breeder male Crj: Wistar rats, weighing…

Comparison

Electrical pacing at 240 and 300 beats/min with… vs Comparison between 240 bpm and 300 bpm pacing…

Design

Preclinical

Authors

SSSusumu SakataNational Institute for Land and Infrastructure Management YOYoshimi OhgaOkayama University TATakehisa AbeHokkaido University Hospital

Discussion

Member takes

Implication

Supports PVA-independent VO2 as heart rate-independent contractility index in animal models; leaves open clinical translation.

Key Points

To determine whether the oxygen cost of left ventricular contractility depends on heart rate in blood-perfused excised rat hearts.
Assessed myocardial oxygen consumption per beat and systolic pressure-volume area in blood-perfused, cross-circulated excised rat hearts.
Gradually increased left ventricular contractility using calcium at a midrange volume while alternating pacing rates between 240 and 300 beats per minute.
Baseline relations between myocardial oxygen consumption and systolic pressure-volume area showed no significant differences between 240 and 300 beats per minute.
Slopes comparing pressure-volume area-independent oxygen consumption to left ventricular contractility did not differ significantly between 240 and 300 beats per minute, demonstrating rate independence.

Structured PICO

Population

12 excised, cross-circulated rat heart preparations from retired breeder male Crj: Wistar rats, weighing 630653 g

Intervention

Electrical pacing at 240 and 300 beats/min (bpm) with gradually enhanced left ventricular contractility by intracoronary calcium infusion

Comparator

Comparison between 240 bpm and 300 bpm pacing rates

Outcome

Dependency of oxygen cost of left ventricular contractility on heart rate (slopes of PVA-independent VO2 and left ventricular contractility relations)surrogate

The oxygen cost of left ventricular contractility is independent of heart rates between 240 and 300 bpm, validating its use for assessing cardiac mechanoenergetics at different pacing rates.

Cite This Study

Sakata et al. (2001) studied this question.

synapsesocial.com/papers/6a6fcbf6f44fa9f079dd4a6b https://doi.org/10.2170/jjphysiol.51.177

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No Dependency of a New Index for Oxygen Cost of Left Ventricular Contractility on Heart Rates in the Blood-Perfused Excised Rat Heart.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

No Dependency of a New Index for Oxygen Cost of Left Ventricular Contractility on Heart Rates in the Blood-Perfused Excised Rat Heart.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider