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October 1, 1989AJP Heart and Circulatory Physiology

Oxygen requirements of the dyskinetic myocardial segment

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Why the study?

Does intracoronary lidocaine-induced dyskinesis alter myocardial oxygen consumption in anesthetized open-chest dogs?

Population

12 anesthetized open-chest dogs

Comparison

Intracoronary infusion of lidocaine to induce… vs Normally contracting circumflex region and basal…

Design

Preclinical

Authors

PGPamela A. GayheartHahnemann University HospitalJVJakob Vinten‐JohansenEmory UniversityWJWilliam E. JohnstonLawrence Berkeley National Laboratory

Discussion

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Implication

Alerts to oxygen wasting in experimental dyskinetic arrest; leaves open translation to human stunned myocardium.

Key Points

  • To measure the oxygen consumption of a noncontracting myocardial segment subjected to passive systolic stretch.
  • Studied 12 anesthetized open-chest dogs administered intracoronary lidocaine (0.25 mg/ml) into the left anterior descending artery to induce regional dyskinesis.
  • Measured segmental shortening sonomicrometrically and regional oxygen consumption (MVO2) using arteriovenous oxygen differences and transmural blood flow under normal and unloaded conditions.
  • Arrested and dyskinetic myocardial segments exhibited only a 33% reduction in MVO2 (P < 0.05) despite the complete loss of active contractile function.
  • Eliminating systolic bulging via ventricular unloading reduced MVO2 in the arrested segment to basal requirements of 2.65 ml O2·min⁻¹·100 g⁻¹.

Structured PICO

Does intracoronary lidocaine-induced dyskinesis alter myocardial oxygen consumption in anesthetized open-chest dogs?

P
Population
12 anesthetized open-chest dogs
I
Intervention
Intracoronary infusion of lidocaine (0.25-mg/ml dose) to induce dyskinesis in the left anterior descending (LAD) region
C
Comparator
Normally contracting circumflex (Cfx) region and basal requirements (ventricular unloading)
O
Outcome
Myocardial oxygen consumption (MVO2) measured by arterial-venous oxygen content differences and transmural blood flowsurrogate

Myocardial oxygen consumption in a pharmacologically arrested myocardial segment undergoing systolic bulging is paradoxically high relative to both basal requirements and normally contracting segments.

Cite This Study

Gayheart et al. (1989) studied this question.

synapsesocial.com/papers/6a905202fdaee66aea840a03https://doi.org/10.1152/ajpheart.1989.257.4.h1184
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Also Consider

Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context:

  1. 1Regional function, blood flow, and oxygen utilization relations in repetitively occluded-reperfused canine myocardium1991 · 28 citations
  2. 2Effect of dopamine on local segment work and O2 consumption in collateral-dependent myocardium1994 · 1 citations
  3. 3Effect of Arterial Hypoxia on Myocardial Oxygen Consumption1973 · 31 citations
  4. 4Metabolic mediation of single brief diastolic occlusion reactive hyperemic responses1987 · 3 citations
  5. 5Effect of Inotropic Agents on the Localized Dyskinesis of Acutely Ischemic Myocardium1974 · 25 citations