What question did this study set out to answer?

The aim is to understand how metabolic changes during low-flow ischemia affect ventricular repolarization in the heart.

August 1, 1998AJP Heart and Circulatory Physiology

Changes in ventricular repolarization during acidosis and low-flow ischemia

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Population

Langendorff-perfused ferret heart model

Comparison

Low-flow ischemia, metabolic acidosis, and… vs Control flow / baseline conditions

Design

Preclinical

Authors

HBH BethellUniversity of Cambridge JVJamie I. VandenbergElectrophysiology GSGerry A. SmithUniversity of Cambridge

Discussion

Member takes

Implication

Hypothesis-generating for acidosis-driven KATP activation in ischemia; should not yet influence clinical practice.

Key Points

The aim is to understand how metabolic changes during low-flow ischemia affect ventricular repolarization in the heart.
Used 31P NMR spectroscopy to monitor metabolic parameters.
Applied suction electrodes to study epicardial monophasic action potentials.
Used 86Rb as a tracer for K+-equivalent efflux in Langendorff-perfused ferret heart.
APD90 shortened from 261 +/- 4 ms to 213 +/- 8 ms during 1-5 min of ischemia.
A fivefold increase in 86Rb efflux rate was observed during marked APD90 shortening.
Acidosis caused activation of KATP channels, leading to APD90 shortening, inhibited by glibenclamide.

Structured PICO

Population

Langendorff-perfused ferret heart model

Intervention

Low-flow ischemia (7.5% of control flow), metabolic acidosis (30 mM lactate), and respiratory acidosis (15% PCO2) with or without KATP-channel blockers (glibenclamide and 5-hydroxydecanoate)

Comparator

Control flow / baseline conditions

Outcome

Action potential duration at 90% repolarization (APD90)surrogate

In a ferret heart model, acidosis during low-flow ischemia activates KATP channels despite normal ATP levels, causing action potential shortening.

Cite This Study

Bethell et al. (1998) studied this question.

synapsesocial.com/papers/6a6f3f00e5469ee92be0449f https://doi.org/10.1152/ajpheart.1998.275.2.h551

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Changes in ventricular repolarization during acidosis and low-flow ischemia

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Changes in ventricular repolarization during acidosis and low-flow ischemia

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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