Myocardial layer-specific analysis of ischemic memory using speckle tracking echocardiography

Area of Science:

• Cardiology
• Echocardiography
• Myocardial Ischemia

Background:

• Post-systolic shortening (PSS) using speckle tracking echocardiography (STE) enables myocardial ischemic memory imaging.
• The endocardial layer's vulnerability to ischemia suggests its assessment is key for detecting ischemic memory.

Purpose of the Study:

• To evaluate the utility of layer-specific STE analysis for detecting myocardial ischemic memory.
• To assess circumferential and radial strain and post-systolic strain index (PSI) in different myocardial layers during ischemia and reperfusion.

Main Methods:

• Serial echocardiography was performed on nine dogs undergoing 2-minute coronary occlusion followed by reperfusion.
• STE was used to analyze regional circumferential and radial strain in endocardial, mid-wall, and epicardial layers.
• Circumferential and radial PSI were calculated for each layer in risk and normal areas.

Main Results:

• Systolic strains decreased during occlusion but recovered post-reperfusion in all layers.
• Circumferential PSI significantly increased during occlusion and remained elevated post-reperfusion in endocardial and mid-wall layers.
• Radial PSI showed non-significant increases post-reperfusion, and no significant changes were observed in the normal area.

Conclusions:

• Layer-specific STE analysis is valuable for assessing myocardial function after ischemia.
• Circumferential PSS in the endocardial and mid-wall layers effectively detects myocardial ischemic memory.
• STE provides a non-invasive method for evaluating regional myocardial response to ischemic events.