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 (two dimensional) 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 specifity of 90.2% for detection of myocardial viability [1]. Low dose dobutamine infusion (10 microgram/Kg body weight/minute) 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 18FDG PET (18 fluorodeoxy glucose 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 Ran H et al. Clinic value of two-dimensional speckle tracking combined with adenosine stress echocardiography for assessment of myocardial viability. Echocardiography. 2012 Jul;29(6):688-94. Hoffmann R...
Source: Cardiophile MD - Category: Cardiology Authors: Tags: General Cardiology Source Type: blogs