What question did this study set out to answer?

To determine the extent of blood flow reduction required to alter high-energy phosphates and pH, and to evaluate how closely these metabolic shifts track changes in myocardial perfusion.

May 1, 1989Circulation ResearchOpen Access

Response of myocardial metabolites to graded regional ischemia: 31P NMR spectroscopy of porcine myocardium in vivo.

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Why the study?

Does graded regional ischemia alter myocardial high energy phosphates and pH in an in vivo porcine model?

Population

in vivo porcine model of graded coronary stenosis

Comparison

Graded regional ischemia vs Normal blood flow (baseline)

Design

Preclinical

Authors

SSSaul SchaeferUniversity of California Davis Medical Center SCS. Albert CamachoOregon Health & Science University JGJoel R. GoberLAC+USC Medical Center

Discussion

Member takes

Implication

PCr/Pi sensitivity to mild ischemia in pigs does not alter practice; leaves open validation as human biomarker.

Key Points

To determine the extent of blood flow reduction required to alter high-energy phosphates and pH, and to evaluate how closely these metabolic shifts track changes in myocardial perfusion.
Employed 31P nuclear magnetic resonance spectroscopy in an in vivo porcine model undergoing graded coronary stenosis.
Concurrently measured regional subendocardial blood flow and myocardial phosphate compounds across steady-state ischemia levels up to an 80% flow reduction.
ATP levels remained stable across all degrees of graded ischemia, while phosphocreatine, inorganic phosphate, and pH changed progressively once blood flow fell below 50% of normal.
The phosphocreatine-to-inorganic-phosphate (PCr/Pi) ratio correlated strongly with subendocardial blood flow (r = 0.94) and dropped by 25% following a blood flow reduction of just 21%.

Structured PICO

Does graded regional ischemia alter myocardial high energy phosphates and pH in an in vivo porcine model?

Population

in vivo porcine model of graded coronary stenosis

Intervention

Graded regional ischemia (subendocardial blood flow reduced by as much as 80%)

Comparator

Normal blood flow (baseline)

Outcome

Changes in high energy phosphates (ATP, phosphocreatine, inorganic phosphate) and pH measured by 31P nuclear magnetic resonance spectroscopysurrogate

The PCr/Pi ratio is a sensitive marker of myocardial ischemia, demonstrating that in vivo energy status is closely coupled to myocardial blood flow.

Cite This Study

Schaefer et al. (1989) studied this question.

synapsesocial.com/papers/6a1e9857d258f1f64202b522 https://doi.org/10.1161/01.res.64.5.968

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Response of myocardial metabolites to graded regional ischemia: 31P NMR spectroscopy of porcine myocardium in vivo.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Response of myocardial metabolites to graded regional ischemia: 31P NMR spectroscopy of porcine myocardium in vivo.

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

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