Strain and strain rate imaging for assessment of myocardial viability

Strain and strain rate imaging for assessment of myocardial viability

Myocardial strain is a measure of deformation of a myocardial segment relative to its initial length. Strain rate is the rate at which the deformation occurs. This is in effect the gradient between velocities at two points. Strain and strain rate can be measured echocardiographically using tissue Doppler and 2D speckle tracking. A change of radial myocardial strain of more than 9.5% has been shown to have a sensitivity of 83.9% and a specificity of 81.4% for detection of myocardial viability. Change in longitudinal myocardial strain more than 14.6% had a sensitivity of 86.7% and specificity of 90.2% for detection of myocardial viability [1].

Low dose dobutamine infusion along with strain rate assessment is useful to assess myocardial viability. Increase in peak systolic strain rate of more than -0.23/s gave a sensitivity of 83% and specificity of 84% compared with 18 fluorodeoxyglucose positron emission tomography as gold standard for detection of myocardial viability [2]. Thus increase in peak systolic strain rate during low dose dobutamine infusion permits discrimination between viable and non viable myocardial segments.

References

1. Ran H, Zhang PY, Fang LL, Ma XW, Wu WF, Feng WF. Clinic value of two-dimensional speckle tracking combined with adenosine stress echocardiography for assessment of myocardial viability. Echocardiography. 2012 Jul;29(6):688-94.

2. Hoffmann, Altiok E, Nowak B, Heussen N, Kühl H, Kaiser HJ, Büll U, Hanrath P. Strain rate measurement by doppler echocardiography allows improved assessment of myocardial viability inpatients with depressed left ventricular function. J Am Coll Cardiol. 2002 Feb 6;39(3):443-9.