Surgical Treatment of Chronic Constrictive Pericarditis by Ujjwal K. Chowdhury & Lakshmi Kumari Sankhyan

Author:Ujjwal K. Chowdhury & Lakshmi Kumari Sankhyan
Language: eng
Format: epub
ISBN: 9789819958085
Publisher: Springer Nature Singapore

10.2 Strain by Speckle Tracking

Speckle tracking is a post-processing computer algorithm that uses routine grey scale digital images [20, 36, 46, 47, 50, 51, 65–69, 96]. Briefly, routine grey scale digital images of the myocardium contain unique speckle patterns.

On the myocardial wall, a user-defined zone of interest is positioned. The image-processing method automatically splits regions into blocks of pixels while monitoring steady patterns of speckles inside this region of interest. Subsequent frames are then automatically analysed by searching for the new location of the speckle patterns within each of the blocks, using correlation criteria and the sum of absolute differences. The location shift of these acoustic markers from frame to frame depicts tissue movement provides the spatial and temporal data used to calculate velocity vectors. Temporal alterations in these stable speckle patterns are identified as moving farther apart or closer together creating a series of regional strain vectors.

Because strain information is independent of the Doppler angle of incidence like tissue Doppler imaging strain, several more strain analyses are possible, including longitudinal, circumferential, radial, and rotational [20, 36, 47, 50, 51, 65–68, 96]. This recently developed technique for characterization and quantification of myocardial deformation provided data noninvasively for better assessment of the efficacy of pericardiectomy. (i.e. in chronic constrictive pericarditis, the epicardial dysfunction leads to depressed Global Circumferential Strain (GCS) and Left Ventricular Torsion (LVT), whereas Global Longitudinal Strain (GLS) and Global Radial Strain (GRS) are preserved).

Perioperative mortality is defined as death that occurs within 30 days of surgery. Cardiac-related death is defined as death due to cardiac causes, such as progressive congestive cardiac failure [2, 4–12]. Hypoproteinemia is defined as serum albumin level less than 3.5 g/dl. Renal dysfunction is defined as serum creatinine more than 2.0 g/dl [2, 4–17, 94].

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