Experimental validation of circumferential, longitudinal, and radial 2-dimensional strain during dobutamine stress echocardiography in ischemic conditions
Reant P, Labrousse L, Lafitte S, Bordachar P, Pillois X, Tariosse L, Bonoron-Adele S, Padois P, Deville C, Roudaut R, Dos Santos P
The detection of a regional dysfunction by 2D echocardiography requires a critical ischemic mass of at least 20% of transmural wall thickness and about 5% of the total myocardial mass. Thus relatively milder and more localized forms of myocardial ischemia do not leave echocardiographic fingerprints and represent the physiological scotoma of the echocardiographic eye when compared ischemia, at least when radial strain and regional systolic thickening or (regional or global) ejection fraction are considered. Initial forms of contractile dysfunction can, however, more selectively affect longitudinal and circumferential strain, both at baseline and during stress-induced ischemia of mild degree.
Reference: J Am Coll Cardiol 2008; 51:149-57
Myocardial deformation imaging based on ultrasonic pixel tracking to identify reversible myocardial dysfunction
Becker M, Lenzen A, Ocklenburg C, Stempel K, Kuhl H, Neizel M, Katoh M, Kramann R, Wildberger J, Kelm M, Hoffmann R
In myocardial infarction, transmural extension or scar distribution in the infarct zone is proportionally related to the reduction in systolic function measured by the radial transmural velocity gradient or strain-rate imaging or peak radial strain using the speckle-tracking techniques.
Reference: J Am Coll Cardiol 2008; 51:1473-81
Detection of postischemic regional left ventricular delayed outward wall motion or diastolic stunning after exercise-induced ischemia in patients with stable effort angina by using color kinesis
Ishii K, Miwa K, Sakurai T, Kataoka K, Imai M, Kintaka A, Aoyama T, Kawanami M
Both tissue Doppler imaging and color kinesis provide quantitative information on the magnitude of regional wall motion, color kinesis can also explore apical unction (where tissue Doppler velocities are too low) and adds information regarding the timing of endocardial motion in both systole and diastole and may also have a role in the assessment of regional diastolic function. Regional left ventricular delayed outward wall motion or diastolic stunning after exercise-induced ischemia can last 1h after stress, when normal regional systolic function was completely restored.
Reference: J Am Soc Echocardiogr 2008; 21:309-14
The quantification of dipyridamole induced changes in regional deformation in normal, stunned or infarcted myocardium as measured by strain and strain rate: an experimental study
Marciniak M, Claus P, Streb W, Marciniak A, Boettler P, McLaughlin M, D'Hooge J, Rademakers F, Bijnens B, Sutherland GR
Experimental studies show that parameters derived from strain-rate imaging can be helpful in identifying and quantifying ischemia-induced myocardial abnormalities and in identifying viable myocardium, whose strain rate is normalized in stunned areas following inotropic challenge with dobutamine or dipyridamole.
Reference: Int J Cardiovasc Imaging 2008; 24:365-76
Abraham TP, Pinheiro AC
Some disadvantages of speckle tracking are the lower frame rate in comparison with TDI, influenced by image quality, examination of strain rather than strain rate, and reduced combination with contrast echocardiography for enhancement of border detection.
Reference: J Am Coll Cardiol 2008; 51:158-60