Regional wall function before and after acute myocardial infarction; an experimental study in pigs
Ulrika S Pahlm, Joey F A Ubachs, Einar Heiberg
1Department of Clinical Physiology, Clinical Sciences, Lund University Hospital, SE-22185 Lund, Sweden. hakan.arheden@med.lu.se.
BMC Cardiovascular Disorders
|September 15, 2014
Summary
Cardiac magnetic resonance (CMR) wall thickening and velocity encoded (VE) strain analysis can differentiate myocardial segments after acute myocardial infarction (AMI), but with limited accuracy. These methods show changes in regional function, distinguishing ischemic from remote areas.
Area of Science:
- Cardiovascular Imaging
- Myocardial Function Assessment
- Acute Myocardial Infarction
Background:
- Left ventricular function is significantly altered following acute myocardial infarction (AMI).
- Cardiac magnetic resonance (CMR) techniques, including wall thickening and velocity encoded (VE) strain analysis, are crucial for assessing regional myocardial function.
- Differentiating between ischemic, adjacent, and remote myocardial segments post-AMI is essential for understanding disease progression and guiding treatment.
Purpose of the Study:
- To investigate changes in regional myocardial wall function using CMR wall thickening and VE-strain after acute myocardial infarction.
- To determine the ability of these CMR parameters to differentiate between ischemic, adjacent, and remote left ventricular segments.
Main Methods:
- Ten pigs underwent baseline CMR for wall thickening and VE-strain assessment.
- Acute myocardial infarction was induced, followed by myocardial perfusion SPECT (MPS) to identify the ischemic area.
- Regional wall function was measured by wall thickening and VE-strain before and after ischemia, with segments categorized as ischemic, adjacent, or remote based on MPS findings.
Main Results:
- Wall thickening significantly decreased in ischemic and adjacent segments but increased in remote segments post-ischemia.
- Both radial and longitudinal strain significantly decreased in ischemic and adjacent segments, while radial strain increased in remote segments.
- Receiver Operating Characteristic (ROC) analysis established differentiation thresholds with 70-80% sensitivity and 72-77% specificity for ischemic segments.
Conclusions:
- CMR wall thickening and VE-strain can establish differentiation thresholds between ischemic, adjacent, and remote segments post-AMI.
- The clinical applicability of these thresholds is limited due to suboptimal sensitivity and specificity.
- Edema was observed primarily in ischemic regions, extending into adjacent and remote segments, with a noted increase in radial strain in remote areas.
