Investigating Cardiac Function Using Motion and Deformation Analysis in the Setting of Coronary Artery Disease

In the last decade, noninvasive cardiac imaging has played an increasing role in cardiology. As one of the most widespread clinically used techniques, echocardiography has witnessed several technical developments in imaging modalities and image analysis. One of the most recent has been the introduction of velocity-based strain-rate imaging and speckle tracking to quantify regional deformation.1Coronary artery disease induces important changes in regional myocardial function. Both acute ischemia and chronic ischemia decrease regional wall motion and thickening. Despite recent technical developments in clinical cardiac imaging, the evaluation of regional radial and longitudinal function is often based on visual interpretation of wall motion. This is both qualitative and subjective.This paper discusses regional myocardial deformation and motion, studied in different (experimental) substrates of coronary artery disease, from acute ischemia to chronic infarction. It will be shown that regional deformation at rest, combined with observations during a dobutamine challenge, can uniquely discriminate the different ischemic substrates.Both radial and longitudinal regional peak systolic velocities show a significant fall after β-blockade2,3 but no added effect of additional pacing. Regional displacement shows a tendency to decrease with β-blockade. With the addition of pacing a further significant reduction in displacement takes place. The transmyocardial velocity gradient (the difference between epicardial and endocardial peak velocity, divided by their distance4–6) is influenced by β-blockade in the same way as peak velocities and is not altered by changes in heart rate during β-blockade. With a dobutamine infusion, myocardial velocities increase.2 With induced changes in contractility, either by dobutamine or β-blockade, peak systolic velocities correlate well with fractional shortening, regional stroke work, end-systolic and maximal elastance, as well as preload recruitable stroke work.On the basis of velocities, regional myocardial deformation properties can be assessed noninvasively both in the radial and longitudinal directions. An excellent …