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July 17, 2001CirculationOpen Access

Transmural Distribution of Three-Dimensional Systolic Strains in Stunned Myocardium

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Key result

Myocardial ischemia and reperfusion in dogs caused a significant transmural gradient of dysfunction in radial segments (24% endocardium vs 16% epicardium; P<0.05), but not in fiber segments.

Why the study?

Does ischemia/reperfusion cause a transmural gradient of dysfunction in stunned myocardium in dogs?

Population

Open-chest anesthetized dogs (n=8)

Comparison

15 minutes of left anterior descending coronary… vs Baseline (before occlusion)

Design

Preclinical

Follow-up

2 hours of reperfusion

Authors

RMReza MazhariJOJeffrey H. OmensRPRichard S. Pavelec

Discussion

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Overview

Fiber dysfunction may predominate over perfusion deficit in reperfusion stunning; challenges consensus and leaves open human relevance.

Key Points

  • To assess transmural distributions of 3D systolic strains in stunned myocardium during ischemia and reperfusion.
  • Measured 3D systolic strains in open-chest anesthetized dogs (n=7) before and after 15 minutes of coronary artery occlusion and during 2 hours of reperfusion.
  • Evaluated regional blood flow differences at epicardium and endocardium during ischemia and subsequent changes in end-systolic fiber lengths.
  • Regional myocardial blood flow was reduced 84% at the endocardium and 32% at the epicardium during ischemia (P<0.005).
  • End-systolic fiber lengths showed no significant transmural gradient despite blood flow differences: 23+/-8% epicardium versus 21+/-4% endocardium (P<0.05).
  • Significant 3D diastolic dysfunction was observed in the ischemic-reperfused myocardium transmurally.

Structured PICO

Does ischemia/reperfusion cause a transmural gradient of dysfunction in stunned myocardium in dogs?

P
Population
Open-chest anesthetized dogs (n=8)
I
Intervention
15 minutes of left anterior descending coronary artery occlusion followed by 2 hours of reperfusion
C
Comparator
Baseline (before occlusion)
O
Outcome
Transmural distributions of 3D systolic strains relative to local myofiber axessurrogate

Main Result

Absolute Event Rate: 24% vs 16%

p-value: p=<0.05

Systolic fiber dysfunction, rather than the degree of perfusion deficit during the preceding ischemic period, may be the main determinant of myocardial dysfunction during reperfusion in stunned myocardium.

Cite This Study

Mazhari et al. (2001) studied Stunned myocardium (n=8). Left anterior descending coronary artery occlusion and reperfusion vs. Epicardium (vs Endocardium) was evaluated on Transmural distribution of 3D systolic strains (radial segment thinning at end systole) (p=<0.05). Myocardial ischemia and reperfusion in dogs caused a significant transmural gradient of dysfunction in radial segments (24% endocardium vs 16% epicardium; P<0.05), but not in fiber segments.

synapsesocial.com/papers/6a154b5779ff98d0de4e657ehttps://doi.org/10.1161/01.cir.104.3.336
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Also Consider

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

  1. 1Transmural myocardial deformation in the ischemic canine left ventricle.1991 · 108 citations
  2. 2Structural basis of regional dysfunction in acutely ischemic myocardium2000 · 71 citations
  3. 3Transmural distribution of myocardial tissue growth induced by volume-overload hypertrophy in the dog.1991 · 39 citations
  4. 4Time course and determinants of recovery of function after reversible ischemia in conscious dogs1988 · 222 citations
  5. 5Biaxial mechanics of the passively overstretched left ventricle1997 · 44 citations