Regional Myocardial Deformation Research Articles

Quest for Diastolic Prognostic Indicators of Clinical Outcome After Acute Myocardial Infarction

Immediately after acute infarction, the region of the myocardium ceases to contract, and over the next 72 hours, the infarct zone stretches and thins, a process known as infarct expansion. This regional left ventricular wall thinning and failure to contract perturb the normally uniform distribution of the stress/strain relationship that preserves cardiac architecture and function. Simultaneous with these early biomechanical changes, myocyte necrosis releases a number of cytokines that, together with the local increase in the regional myocardial deformation, cause stretch activation of a portfolio of matrix metalloproteinases that initiate myocardial repair. Article p 2591 The stability of myocardial repair after acute myocardial infarction is determined by the balance between the distending forces from ventricular dilatation resulting from infarct expansion and the restraining forces from deposition of a viscoelastic collagen scaffold by the extracellular matrix that increases the tensile strength of the scar. The dynamic equilibrium between collagen degradation and collagen deposition is modulated by a number of activated cytokines and neurohormones that normally result in buttressing the infarct and adjacent border zones, preventing progressive remodeling to heart failure. Changes in the composition of the myocardium in terms of increased collagen content during and after repair of the infarct zone in forming a fibrous tissue scar alter the material properties of the myocardium after myocardial infarction and confer on the heart increased myocardial and chamber stiffness. These alterations in left ventricular composition, architecture, and chamber/myocardial stiffness affect left ventricular filling dynamics, the rate of detachment of cross-linking, and sequestration of cytosolic calcium by the sarcoplasmic reticulum, all of which affect diastolic function as much as systolic function. However, most studies of the predictors of clinical outcome after myocardial infarction have focused almost exclusively on ejection-phase indexes of systolic contraction. Factors shown to be powerful predictors of clinical outcome after myocardial …

Two-dimensional strain to assess regional left and right ventricular longitudinal function in 100 normal foetuses

Previous reports have demonstrated that myocardial velocities are not sufficiently sensitive in foetal heart studies. Strain (S) imaging is a new non-invasive ultrasonic technique able to quantify regional myocardial deformation properties. Strain imaging has a superior sensitivity than myocardial velocity for non-invasive assessment of ventricular function. However, Doppler-derived strain imaging has been used to quantify myocardial deformation properties in the foetal heart with rather limited results, because of angle dependency, sensitivity to extracardiac movement, the need for good-quality images, long and time-consuming post-processing and the low reproducibility of Doppler-derived strain. Recently, a novel method for motion estimation based on two-dimensional (2D) tissue tracking strain (2D-S) echocardiography using time-domain processing has been developed, providing rapid assessment of regional myocardial strain that is independent of both cardiac translation and angle dependency, with a very good reproducibility. However, no information on 2D-S in human foetuses has so far been provided. We studied 100 consecutive normal foetuses (gestation range: 20-32 weeks; no evidence of structural cardiovascular disease by 2D echo and Doppler study) using 2D-S imaging. Left ventricle (LV) and right ventricle (RV) peak myocardial negative strain values were obtained. Strain data were obtained from all the studied subjects, the duration of post processing was 3 +/- 2 min for each patient dataset. Peak longitudinal deformation parameters were homogeneous in all the three studied walls (strain: septum = -25 +/- 5%; lateral wall = -25 +/- 4%; RV free wall = -24 +/- 4%; P = NS). There were significant correlations between gestational age and peak longitudinal strain (P < 0.001; R: -0.73). Inter and intra-observer variability for strain was good, <3 and <6%, respectively. This study demonstrated that 2D-S is a feasible and reproducible approach to assess regional ventricular function in the foetal heart, ready for the clinical application.

Detection of Regional Myocardial Dysfunction in Patients with Acute Myocardial Infarction Using Velocity Vector Imaging

Velocity vector imaging (VVI) is a new echocardiographic technique of measuring regional myocardial velocities and deformation. Our aim was to evaluate the feasibility and accuracy of VVI in defining regional functional abnormalities in patients with an acute myocardial infarction. Standard echocardiography and delayed enhancement (DE) magnetic resonance imaging were performed in 32 patients (29 men, mean age 61.2 +/- 8.1 years) within 36 hours of primary angioplasty. Twenty healthy volunteers (16 men, mean age 34.6 +/- 6.3 years) served as control subjects. Using VVI for offline analysis, segmental longitudinal deformation indices were measured. Infarcted, adjacent, and remote left ventricular segments were defined according to DE magnetic resonance imaging and coronary angiography. Infarct transmurality was also graded based on the DE extent within each segment on DE magnetic resonance imaging (0%-25%, 26%-50%, 51%-75%, and >76% of wall thickness). As compared with remote segments, myocardial infarction segments had significantly lower longitudinal systolic strain (S) (-9.6% vs -14.6%, P < .0001), lower S rate (-0.75 vs -1.08 s(-1), P < .0001), and a higher postsystolic S index (21% vs 8.3%, P < .001). By receiver operating characteristic curve analysis, a myocardial peak systolic longitudinal S lower than -6.5% in at least one ventricular segment showed best predictive value (94%) for detecting an infarcted left ventricle. Peak systolic S and S rate were useful predictors of the presence of regional dysfunction, and for the localization and transmural extent of the infarct. VVI is a promising new tool for studying myocardial motion and deformation with good feasibility in the clinical setting. The assessment of myocardial longitudinal systolic S and S rate with VVI can be used to identify the presence, location, and the transmural extent of myocardial infarction.

Longitudinal strain analysis for efficacy assessment of myocardial cell therapy

Aims: Novel echocardiographic techniques can quantify regional myocardial deformation (strain) and distinguish between passive and active wall motion. We hypothesized that this technique may help delineate cell therapy-induced changes in regional LV contractility.

Investigating Cardiac Function Using Motion and Deformation Analysis in the Setting of Coronary Artery Disease

In the last decade, noninvasive cardiac imaging has played an increasing role in cardiology. As one of the most widespread clinically used techniques, echocardiography has witnessed several technical developments in imaging modalities and image analysis. One of the most recent has been the introduction of velocity-based strain-rate imaging and speckle tracking to quantify regional deformation.1 Coronary artery disease induces important changes in regional myocardial function. Both acute ischemia and chronic ischemia decrease regional wall motion and thickening. Despite recent technical developments in clinical cardiac imaging, the evaluation of regional radial and longitudinal function is often based on visual interpretation of wall motion. This is both qualitative and subjective. This paper discusses regional myocardial deformation and motion, studied in different (experimental) substrates of coronary artery disease, from acute ischemia to chronic infarction. It will be shown that regional deformation at rest, combined with observations during a dobutamine challenge, can uniquely discriminate the different ischemic substrates. Both radial and longitudinal regional peak systolic velocities show a significant fall after β-blockade2,3 but no added effect of additional pacing. Regional displacement shows a tendency to decrease with β-blockade. With the addition of pacing a further significant reduction in displacement takes place. The transmyocardial velocity gradient (the difference between epicardial and endocardial peak velocity, divided by their distance4–6) is influenced by β-blockade in the same way as peak velocities and is not altered by changes in heart rate during β-blockade. With a dobutamine infusion, myocardial velocities increase.2 With induced changes in contractility, either by dobutamine or β-blockade, peak systolic velocities correlate well with fractional shortening, regional stroke work, end-systolic and maximal elastance, as well as preload recruitable stroke work. On the basis of velocities, regional myocardial deformation properties can be assessed noninvasively both in the radial and longitudinal directions. An excellent …

Regional myocardial deformation in children with hypertrophic cardiomyopathy: morphological and clinical correlations

Hypertrophic cardiomyopathy (HCM) is a disease with marked regional differences in wall thickness. However, the relation between myocardial function and wall thickness has not been well studied. Ultrasonic strain rate (SR) imaging makes it possible to study the regional myocardial deformation. We investigated whether regional systolic deformation is reduced in paediatric patients with HCM and evaluated its relation with wall thickness, electrocardiographic pattern, and exercise capacity. We studied 41 children with asymmetric HCM (mean age 12.3 years) and 29 controls. Electrocardiograms, exercise testing (when feasible), and echocardiograms with tissue Doppler imaging were performed. Peak systolic SR, strain, post-systolic shortening, and time to maximal strain were calculated in the longitudinal direction from the basal septum, mid-septum, and basal lateral myocardial segments and in the radial direction from the basal antero-septal and infero-lateral myocardial segments. Children with HCM had a significant reduction in deformation in all myocardial segments when compared with controls. In the HCM group, peak systolic SR and strain were significantly lower in the basal septum when compared with the mid-septal and basal lateral myocardial segments. In the basal septum, post-systolic shortening was significantly higher and time to maximal strain significantly longer than in mid-septal and lateral myocardial segments. A strong inverse curvilinear relation between peak systolic strain and wall thickness was found (r = -0.86, P < 0.001), with no further decrease in the regional myocardial function demonstrated once maximal wall thickness exceeded a Z-score of 3.5. Peak systolic strain in the basal part of the septum correlated inversely with exercise capacity (r = 0.68, P < 0.01). Systolic deformation is significantly and inhomogeneously reduced in children with HCM. This reduction in myocardial function is related to maximal wall thickness and decreased exercise capacity.

Velocity vector imaging in assessing myocardial systolic function of hypertensive patients with left ventricular hypertrophy

To date, most studies about strain and strain rate (SR) are based on Doppler tissue imaging (DTI), which is dependent on the angle between ultrasonic scan line and tissue. Velocity vector imaging (VVI) is a new echocardiographic method based on two-dimensional gray scale imaging, which is angle-independent and can provide more information about cardiac function than DTI. To assess regional myocardial SR in hypertensive patients with left ventricular hypertrophy (LVH) but normal global ejection fraction (GEF) and fractional shortening (FS) using VVI. Using VVI, two-dimensional images were performed in 20 hypertensive patients with LVH and 20 normal control subjects. The segmental systolic peak SR (SRs) in the short-axis view and the apical SRs in the long-axis view were analyzed by offline software. The segmental SRs in the long-axis and short-axis views were significantly lower in the LVH group than in the corresponding segments of the control group. There was no significant difference between the circumferential SRs of different segments in the short-axis view in the LVH and control groups. The circumferential SRs decreased significantly from the endocardium to the middle layer of the myocardium in the short-axis view in the LVH group and in the control group. Hypertensive patients with LVH may have regional LV systolic function impairment despite having normal GEF and FS. The GEF and FS were not the decisive factors of myocardial systolic function in the present study. There was an obvious systolic gradient from the endocardium to the middle layer of myocardium in circumferential SRs in the short-axis view. VVI can be used to accurately recognize and quantify abnormalities of regional myocardial deformation.

Abnormal regional myocardial deformation properties and increased aortic stiffness in normotensive patients with aortic coarctation despite successful correction: an ABPM, standard echocardiography and strain rate imaging study

The long-term follow-up data subsequent to a successful repair of AoC (aortic coarctation) show that life expectancy remains reduced. Previous standard echocardiographic studies have demonstrated normal or increased systolic cardiac function in patients following successful repair of AoC. SR (strain rate) imaging is a new technique able to detect subclinical myocardial abnormalities. In the present study we investigated whether young patients (without hypertension, as assessed using ambulatory blood pressure monitoring and an exercise test) following successful AoC repair already have abnormal myocardial deformation properties, and the relationship of the deformation properties with aortic stiffness. We studied 166 subjects, 83 AoC non-hypertensive patients (mean age 12+/-4 years) a number of years after successful repair of AoC and 83 age- and sex-matched subjects as controls. Peak systolic SR (1/s) for both regional longitudinal and radial function was assessed. The aortic stiffness index was calculated from the echocardiographically derived thoracic aortic diameters, and the measurement of blood pressure was obtained by cuff sphygmomanometry. The LV (left ventricular) ejection fraction was significantly increased in AoC patients, whereas regional longitudinal SRs were significantly reduced (-1.1+/-0.9 compared with -2+/-0.5, P<0.0001) in patients. The aortic stiffness index was significantly increased in AoC patients (12+/-9, P<0.0001). At multilinear regression analysis, age at repair (P=0.005; coefficient, -0.201; S.E.M., 0.027) and the aortic stiffness index (P=0.0029; coefficient, 0.334; S.E.M., 0.423) predicted longitudinal SR. Despite the presence of a successful repair for AoC, in the absence of hypertension, longitudinal deformation properties were significantly impaired. Moreover, the degree of longitudinal SR impairment was correlated with age at repair and aortic stiffness. Early repair can delay the onset of hypertension in postcoarctectomy patients, but cannot prevent the innate structural and functional abnormalities of the aorta and their deleterious effect on myocardial deformation properties.

Three-dimensional Evaluation of Dobutamine-induced Changes in Regional Myocardial Deformation in Ischemic Myocardium Using Ultrasonic Strain Measurements: The Role of Circumferential Myocardial Shortening

Early identification of myocardial ischemia during high-dose dobutamine stress (DOB) has important clinical implications. Myocardial strain imaging can evaluate regional myocardial contractility in the radial, longitudinal, and circumferential directions. The aim of this study was to assess precisely the differences in deterioration of myocardial deformation among the 3 directions in patients with newly developed myocardial ischemia during high-dose (40 microg/kg/min) DOB infusion. Color Doppler tissue 2-dimensional images were recorded during DOB infusion in 20 patients without myocardial ischemia and 25 patients with scintigraphically diagnosed myocardial ischemia caused by left anterior descending coronary artery stenosis. In the offline analysis, systolic radial strain (Sr), longitudinal strain (Sl), and circumferential strain (Sc) were determined in the anteroseptal and anterolateral left ventricular walls. In 20 patients without myocardial ischemia, the peak systolic strains significantly increased in all 3 directions during DOB infusion at rates between 5 and 10 microg/kg/min (Sr 50%-69%, Sl 27%-36%, Sc 29%-38%, all P < .01) with a greater rate of change in the Sr (1.8 and 1.9 times, respectively, P < .001) than in the Sl and Sc. However, the peak systolic strains decreased significantly during DOB infusion at rates between 5 and 10 microg/kg/min in all 3 directions (Sr 56%-35%, Sl 27%-13%, both P < .01; Sc 29%-7%, P < .001) with the greatest rate of change in the Sc in 25 patients with newly developed myocardial ischemia. In conclusion, circumferential myocardial shortening deteriorated to a greater extent during DOB infusion in patients with coronary artery stenosis, and its measurement is a promising tool for detecting newly developed myocardial ischemia.

An Ultrasound Speckle Tracking (Two-Dimensional Strain) Analysis of Myocardial Deformation in Professional Soccer Players Compared With Healthy Subjects and Hypertrophic Cardiomyopathy

Deformation analysis using 2-dimensional strain echocardiography can detect early systolic function abnormalities in patients with left ventricular hypertrophy. This study was designed to characterize global and regional myocardial deformation using 2-dimensional strain in professional soccer players (PSPs) compared with control subjects and patients with hypertrophic cardiomyopathy (HC). Twenty nine PSPs, 26 patients with HC, and 17 controls were investigated at rest using transthoracic echocardiography with 2-dimensional strain analysis. Radial and transverse strains were significantly higher in PSPs compared with controls, whereas longitudinal strain was lower. Compared with patients with HC, athletes had higher values for transverse, radial, and circumferential strains. In pathologic hypertrophic segments, longitudinal strain was lower in patients with HC than in PSPs. In conclusion, 2-dimensional strain can identify specific patterns of myocardial deformation in PSPs, controls, and patients with HC. It has the potential to become a routinely used method for the differentiation of athlete's heart and HC.

739 Non-ischemic fibrosis can be reliably detected by a typical “Double peak sign” extracted from regional myocardial deformation curves

739 Non-ischemic fibrosis can be reliably detected by a typical “Double peak sign” extracted from regional myocardial deformation curves

Systolic Dysfunction in Heart Failure with Normal Ejection Fraction: Speckle-Tracking Echocardiography

Left ventricular (LV) ejection fraction (EF) and LV end-systolic volumes are important measures of LV global function. However, in many patients with symptoms of heart failure, these measures are within normal limits. This condition is classified as heart failure with normal ejection fraction (HFNEF). Reduced EF and increased end-systolic volume, however, require impaired function in a number of LV segments. Therefore, apparently normal systolic function in HFNEF may reflect limited sensitivity of global EF, and assessment of regional systolic function may provide important diagnostic information. The recently introduced method, speckle-tracking echocardiography (STE), represents a simplified, objective, and angle-independent modality for quantification of regional myocardial deformation. The software uses conventional gray-scale B-mode recordings and tracks myocardial speckles, which serve as natural acoustic markers. Radial and longitudinal myocardial deformation can be measured simultaneously from long-axis recordings, radial and circumferential deformation from short-axis recordings, and LV torsion from assessment of apical and basal short-axis rotation. Experimental and clinical studies have demonstrated that the STE method can assess myocardial function accurately in healthy subjects in the settings of acute and chronic ischemia, dyssynchrony, and cardiomyopathy. So far, no STE studies have been performed regarding HFNEF. The purpose of this article is therefore to illustrate the potential of this novel method.

Tissue Doppler and innovative myocardial-deformation imaging techniques for assessment of myocardial viability

Visual analysis of stress echocardiography allows evaluation of myocardial viability in acutely and chronically impaired left-ventricular function. Tissue Doppler and derived echocardiographic imaging techniques provide a tool for quantification of regional left-ventricular function which overcomes the limitations of subjective, experience-dependent reading of stress echocardiography. Regional systolic and diastolic myocardial velocities as well as the derived myocardial-deformation parameters strain and strain rate are impaired in patients with left-ventricular dysfunction. Increase of myocardial velocities, strain and strain rate during stress stimulation are indicators of functional reserve in viable segments, while failure to increase indicates nonviability. Previous studies with very precise determination of regional myocardial deformation have shown that even analysis of resting function without evaluation of the functional reserve during stimulation allows assessment of myocardial viability. New two-dimensional echocardiography-based tissue-tracking techniques yield an angle-independent imaging modality that is likely to further improve the clinical applicability of echocardiographic imaging techniques to define regional myocardial viability. This review attempts to define the role of tissue Doppler and new innovative myocardial-deformation imaging techniques for identification of myocardial viability in patients with impaired left-ventricular function.

Abnormal myocardial deformation properties in obese, non-hypertensive children: an ambulatory blood pressure monitoring, standard echocardiographic, and strain rate imaging study

The prevalence of obesity is increasing among children in the developed world. The association of obesity and abnormal cardiac function is still debated. The reported changes may reflect the role of comorbidities that contribute to ventricular dysfunction. Obese children, without arterial hypertension, may be a unique clinical opportunity to evaluate the effect of obesity, per se, on myocardial function, excluding the influence of possible comorbidities. We sought to define the preclinical effects of obesity on the cardiovascular system, of healthy children with excess weight who have no other clinically appreciable cause of heart disease, using the more sensitive ultrasonic-derived strain and strain rate (SR) imaging. We studied 300 subjects divided into two groups: (i) obese children (Group O: n=150; age, 12+/-3 years); (ii) healthy lean children comparable for age, sex, and pubertal stage (Referents: n=150; mean age, 12+/-3 years). Systolic (SBP) and diastolic blood pressure (DBP), as well as 24 h-SBP and 24 h-DBP were comparable between groups. Left ventricular (LV) mass/height(2.7) was increased (P<0.0001) in Group O (46+/-12 g/m(2.7)) when compared with Referents (31+/-14 gm(2.7)). Standard echocardiographic indices of global systolic function were similar in the two groups. Intima-media thickness measured at the common carotid artery was not significantly different (P=0.4) in obese children (0.46+/-0.09 mm) when compared with Referents (0.45+/-0.07 mm). Obese children showed regional longitudinal peak systolic myocardial deformation properties (SR=-1.4+/-0.7 s(-1)) lower (P<0.0001) than those of Referents (SR=-2.2+/-0.5) in both left and right ventricle. In multivariable analysis, average peak systolic SR was significantly correlated with homeostasis model assessment of insulin resistance (P<0.01; coefficient, 0.02; SE, 0.011), and insulin serum concentration (P<0.01; coefficient, 0.05; SE, 0.023). Average LV peak systolic strain was significantly correlated with body mass index (P=0.0001; coefficient, 0.06; SE, 0.016), LVM/H(2.7) (P=0.006; coefficient, 0.016; SE, 0.018). Our study demonstrated that obesity, in absence of hypertension, is associated with significant reduction in systolic myocardial deformation properties already in childhood involving both right and left ventricle. Obesity not only is a risk factor for later cardiovascular disease, but also is associated with contemporaneous and significant impairment of longitudinal myocardial deformation properties.

Effects of Dual-Chamber Pacing on Regional Myocardial Deformation in Patients With Hypertrophic Obstructive Cardiomyopathy

This study examined the effects of dual-chamber pacing (DDD) on regional myocardial deformation, as determined by echocardiographic strain and strain rate (SR) imaging, in patients with hypertrophic obstructive cardiomyopathy (HOCM). Fourteen patients (11 men, 3 women; mean age 55 +/-16 years) who had been on long-term DDD (mean period 7.4 +/- 2.1 years) underwent strain and SR imaging. Before and after DDD, the peak strain (%) and SR (s(-1)) during systole were assessed in 8 segments in 4 left ventricular (LV) walls. With DDD turned on, peak strain and SR were significantly increased in the basal anteroseptal (strain -10.2 +/- 6.8 to -1.0 +/- 6.4, p<0.005; SR -0.76 +/- 0.46 to 0.05 +/- 0.58, p<0.001) and septal segments (strain -11.2 +/- 8.9 to -2.2 +/- 7.7, p<0.005; SR -0.85 +/- 0.54 to -0.19 +/- 0.75, p<0.05), but not in the basal posterior (strain -15.0 +/- 13.0 to -13.4 +/- 9.2, p=NS; SR -1.37 +/- 0.57 to -1.93 +/- 0.65, p=NS) and lateral segments (strain -18.1 +/- 10.2 to -15.7 +/- 5.6, p=NS; SR -1.33 +/- 0.68 to -0.84 +/- 0.88, p=NS). These findings were associated with a modest, but significant, change in the LV pressure gradient (24 +/- 12 mmHg to 14 +/- 7 mmHg, p<0.001). In patients with HOCM, DDD appeared to produce myocardial lengthening in the basal septum during systole, which may have implications for the mechanism of reducing LV outflow obstruction during DDD.

Strain and Strain Rate Echocardiography

Myocardial function is eventually determined by the shortening and lengthening of myocardium, i.e., myocardial deformation or strain. The exact and direct measure of myocardial deformation has been dependent on the in vitro analysis of myocardial length. This is not an ideal physiological approach due to the change of the surrounding environment, and the process is rather tedious. Thus, this in vitro approach is primarily a research tool. Thanks to recently developed imaging techniques, regional myocardial deformation can now be measured. Using the myocardial tagging technique, one can measure myocardial strain with high accuracy. Currently, this is used as the clinical standard for the noninvasive evaluation of regional function.1 However, due to cost and long time needed for off-line analysis, myocardial tagging by MRI is not routinely utilized for clinical purposes. In 1998 and then in 2000, Heidelm2 and Urheim,3 et al., reported that based on myocardial velocities by tissue Doppler imaging (TOI), the rate of myocardial deformation (strain rate or myocardial velocity gradient) can be calculated. In validation studies, Doppler-derived strain accurately reflected regional myocardial shortening and lengthening when compared to measurements by sonometric crystals. Since then, strain rate imaging (SRI) has been examined in animal and clinical studies for the assessment of cardiac function.

Echocardiographic Strain Imaging for Myocardial Viability

Echocardiographic strain imaging was introduced by Heimdal et al in 19981 as a means to calculate myocardial regional function from tissue Doppler velocity data.2,3 Strain imaging is a variation of the previous concept of tissue Doppler myocardial velocity gradient, which calculates regional thickening independent of passive whole heart motion.4,5 Because routine clinical evaluation of regional function is usually by visual wall-motion assessment, strain imaging has great promise to improve objective quantification of regional function. Strain imaging calculates deformation, which translates clinically to percent shortening in the longitudinal dimension (assessed from apical views) or percent thickening in the radial dimension (assessed from parasternal views).1,6,7 Theoretically, it has the important advantage of differentiating active myocardial motion from passive translational or tethering movements that other echocardiographic-Doppler approaches cannot differentiate. Indeed, there have been literally hundreds of publications over the last 10 years detailing a wide range of experimental and potential clinical applications of strain imaging; however, currently, few centers have adopted strain imaging in their routine clinical practice, preferring visual “eyeball” assessment, even though this is inherently subjective and requires a high level of experience and training.8 An important question remains: Is it now time for strain imaging to be adopted in a widespread clinical sense? Articles pp 3892 and 3901 Two important articles are contained in this issue of Circulation that address the application of strain imaging as a tool to assess myocardial viability: an animal study of experimental ischemia and infarction by Lyseggen et al9 and a clinical study using dobutamine echocardiography with outcome data after revascularization by Hanekom et al.10 The article by Lyseggen et al illustrates the additive value of strain imaging in an elegant open-chest animal model of coronary occlusion and reperfusion. Echocardiographic strain imaging was performed along with simultaneous dimensional …

Quantification of regional left and right ventricular longitudinal function in 75 normal fetuses using ultrasound-based strain rate and strain imaging

Previous reports have demonstrated that myocardial velocities are not sufficiently sensitive in fetal heart studies. Strain (S) and strain rate (SR) imaging is a new noninvasive ultrasonic technique able to quantify regional myocardial deformation properties. SR imaging has a superior sensitivity than myocardial velocity for noninvasive assessment of ventricular function, but this technique has not been used in the fetal heart. Our aim was to evaluate the feasibility of S/SR imaging in the fetal heart and to study characteristics of myocardial deformation properties and their changes with the gestational age in healthy fetuses. We studied 75 normal fetuses (weeks gestation 25 ± 4, no evidence of structural cardiovascular disease by 2-D echo and Doppler study) using S/SR imaging. Left (LV) and right ventricle (RV) peak myocardial systolic, early diastolic and SR values during atrial contraction were obtained but, for S, we measured only peak systolic values. The sample volume was placed in the mid-segment of LV septal, lateral and RV free wall. S and SR curves were obtained in all the studied population. Peak longitudinal systolic deformation was homogeneous in all the walls studied. Moreover, fetal myocardial S and SR during diastole were characterized by a higher deformation during atrial contraction than during early filling. Peak systolic and peak diastolic ratios of regional myocardial deformation properties significantly correlated with the gestational age. Inter- and intraobserver variabilities for S and SR parameters were < 15%, < 18% and < 13%, < 15%, respectively. SR imaging is feasible in selected healthy fetuses, with a limited reproducibility; we presented normal values for the fetal heart; S/SR during fetal life are homogeneous in both LV and RV; and longitudinal myocardial deformation properties increase with the gestational age. (E-mail: giodisal@yahoo.it)

435 Improvement of regional myocardial function during exercise after cell therapy in chronic ischemic cardiomyopathy

Objectives: We sought to examine changes in regional myocardial deformation during exercise echocardiography, before (pre) and 4 months after (post) intracoronary infusion of autologous bone marrow cells (BMC) in patients with severe chronic ischemic cardiomyopathy (ICM). Background: Longitudinal systolic myocardial strain (s) and strain rate (sr) has proven to be useful for quantifying regional myocardial function during stress echocardiography. Effects of intracoronary infusion of autologous BMC on global and regional myocardial function have not been studied in patients with chronic ICM. Methods: Eight patients with dilated LV and EF< 35% underwent a symptom-limited bicycle exercise echocardiography pre and post BMC infusion. Maximum systolic strain (msys) and peak systolic strain rate (psysr) were measured at rest (r) and exercise (e) pre and post BMC in the mid segment of each akinetic area. Intracoronary infusions of BMC were performed into the artery supplying viable territory detected by exercise echocardiography. Results: Twelve akinetic areas were analysed. Three of the 8 anterior and all of the 4 inferior areas presented viability pre BMC.WMSI did not change at rest and decreased from 1.43 40.17 to 1.38 40.16(p=0.02) at exercise. EF, msys and psysr results at rest and exercise are shown in the table.

Recovery of Stunned Myocardium in Acute Myocardial Infarction Quantified by Strain Rate Imaging: A Clinical Study

Strain rate (SR) imaging (SRI) is a tissue Doppler-based method of regional myocardial deformation imaging. The aim of this study was to see whether SRI could quantify changes in myocardial mechanical function after an acute myocardial infarction, and to follow the time course of these changes. In all, 26 consecutive patients with first-time acute myocardial infarctions were examined on days 1, 7, and 90. Segments were analyzed with SRI and wall-motion score. Peak systolic SR in infarcted segments increased significantly in magnitude from day 1 to 7 (-0.45 to -0.68 s -1 , P < .001), but not after day 7. The deformation rate in border zone segments also increased significantly from day 1 to 7 (-0.8 to -0.95 s -1 , P < .05), with no further significant changes at 3 months. In normal segments, peak systolic SR decreased in magnitude during the first week. Systolic strain showed similar results as peak systolic SR. SRI can demonstrate small changes in deformation rate from midinfarct through the infarct and border zone to normal myocardium. It can also show changes over time, probably as a result of recovery of stunned myocardium.