Perfusion versus function: the ischemic cascade in demand ischemia: implications of single-vessel versus multivessel

Howard Leong-Poi1, Se-Joong Rim, D Elizabeth Le

  • 1Cardiac Imaging Center, Cardiovascular Division, University of Virginia School of Medicine, Charlottesville, Va, USA.

Circulation
|February 28, 2002
PubMed

Insights

In demand ischemia, abnormal heart perfusion occurs before functional changes. This perfusion abnormality is more widespread than functional changes and is more pronounced in single-vessel stenosis (SVS) than multivessel stenosis (MVS).

Area of Science:

  • Cardiovascular Physiology
  • Echocardiography
  • Ischemic Heart Disease

Background:

  • Demand ischemia can lead to abnormalities in myocardial perfusion and function.
  • Understanding the sequence and spatial extent of these abnormalities is crucial for diagnosing coronary artery stenosis.
  • Differentiating between single-vessel stenosis (SVS) and multivessel stenosis (MVS) may influence the presentation of ischemic changes.

Purpose of the Study:

  • To investigate the temporal and spatial relationship between abnormal myocardial perfusion and function during demand ischemia.
  • To compare these relationships in the context of single-vessel stenosis (SVS) versus multivessel stenosis (MVS).
  • To determine if perfusion abnormalities precede functional abnormalities and their relative spatial extents.

Main Methods:

  • Nine dogs underwent either SVS or MVS placement with varying stenosis severity.
  • Dobutamine infusion was used to induce demand ischemia.
  • Myocardial perfusion (using myocardial contrast echocardiography) and wall thickening (as a measure of function) were assessed at different dobutamine doses.

Main Results:

  • Abnormal perfusion was detected at lower dobutamine doses than abnormal wall thickening in SVS.
  • The spatial extent of perfusion abnormalities was generally greater than that of functional abnormalities.
  • The spatiotemporal discordance between perfusion and function was less pronounced in MVS compared to SVS.

Conclusions:

  • The findings support the concept of an ischemic cascade where perfusion deficits occur before functional impairments.
  • Abnormal perfusion is a more sensitive indicator of coronary stenosis than abnormal function.
  • Dobutamine echocardiography demonstrates higher sensitivity for MVS detection compared to SVS due to distinct patterns of ischemic changes.
Abstract

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