Both systolic and diastolic dysfunction characterize nonischemic inhibition of myocardial energy metabolism: an experimental strain rate echocardiographic study.

Background: Ischemia is primarily a metabolic event. However, regional functional changes can be affected by structural alterations. We developed an experimental model of sole myocardial energy metabolism inhibition and characterized the resulting regional dysfunction.

Ultrasound strain imaging of altered myocardial stiffness: stunned versus infarcted reperfused myocardium.

Background: In this study we evaluate the diastolic deformation of ischemic/reperfused myocardium and relate this deformation to tissue elastic properties.

Methods And Results: Farm pigs were subjected to left anterior descending coronary artery occlusion followed by reperfusion to create either stunning (n=12) or transmural myocardial infarction (n=12). Ultrasound-derived radial strain rates (SR) and strain were measured in the ischemic and remote walls.

Epicardial ultrasound guidance of coronary catheter placement in an experimental animal model.

We evaluated epicardial ultrasonography with a 10-MHz transducer for coronary catheter guidance in 18 normal pigs. A modified long-axis view of the aortic root was used to direct a coronary catheter into the root, and then with a short-axis view of the aortic root, the catheter tip was placed selectively into either the right or the left main coronary artery. Subsequently, with modified coronary views, an angioplasty infusion catheter was guided with precision to the exact location desired in the coronary artery.

Higher myocardial strain rates during isovolumic relaxation phase than during ejection characterize acutely ischemic myocardium.

Objectives: The aim of this study was to define an index that can differentiate normal from ischemic myocardial segments that exhibit postsystolic shortening (PSS).

Background: Identification of ischemia based on the reduction of regional systolic function is sometimes challenging because other factors such as normal nonuniformity in contraction between segments, tethering effect, pharmacologic agents, or alterations in loading conditions can also cause reduction in regional systolic deformation. The PSS (contraction after the end of systole) is a sensitive marker of ischemia; however, inconsistent patterns have also been observed in presumed normal myocardium.