Tissue Doppler echocardiographic quantification. Comparison to coronary angiography results in Acute Coronary Syndrome patients

Abstract

Background: Multiples indices have been described using tissue Doppler imaging (DTI) capabilities. The aim of this study was to assess the capability of one or several regional DTI parameters in separating control from ischemic myocardium.

Methods: Twenty-eight patients with acute myocardial infarction were imaged within 24-hour following an emergent coronary angioplasty. Seventeen controls without any coronary artery or myocardial disease were also explored. Global and regional left ventricular functions were assessed. High frame rate color DTI cineloop recordings were made in apical 4 and 2-chamber for subsequent analysis. Peak velocity during isovolumic contraction time (IVC), ejection time, isovolumic relaxation (IVR) and filling time were measured at the mitral annulus and the basal, mid and apical segments of each of the walls studied as well as peak systolic displacement and peak of strain.

Results: DTI-analysis enabled us to discriminate between the 3 populations (controls, inferior and anterior AMI). Even in non-ischemic segments, velocities and displacements were reduced in the 2 AMI populations. Peak systolic displacement was the best parameter to discriminate controls from AMI groups (wall by wall, p was systematically < 0.01). The combination IVC + and IVR< 1 discriminated ischemic from non-ischemic segments with 82% sensitivity and 85% specificity.

Conclusion: DTI-analysis appears to be valuable in ischemic heart disease assessment. Its clinical impact remains to be established. However this simple index might really help in intensive care unit routine practice.

Figure 1

Example of a DTI curve analysis. It was manually positioned a region of interest (ROI) at the level of the mitral annulus and three others in the 3 segments of each wall (following the ASE left ventricular segmentation) IVC: peak of velocity recorded at the isivolumic contraction time S: peak of velocity recorded in systole IVR: peak velocity recorded in isvolumic relaxation time E: peak velocity in early diastole A: peak velocity in end-diastole

Figure 2

Example of Tissue tracking curves displayed on Echopac. It was there easy to record the peak (S) of systolic displacement of the same 4 ROI described in figure 1.

Figure 3

Example of Strain analysis; It was there possible to record the degree of systolic shortening or lengthening of the 4 studied ROI.

Figure 4

Representation of IVR (isovolumic relaxation), IVC (isovolumic contraction) peak velocities, early diastolic tissue Doppler velocity (E), systolic tissue Doppler velocity (S), systolic displacement (tissue tracking) and strain in the three segments of each myocardial walls analyzed in the anterior (ANT) myocardial infarction population, in the inferior myocardial infarction one (POST) as in the control group (normal).