Matteo Cameli

Speckle-Tracking Echocardiography A New Technique for Assessing Myocardial Function

Speckle‐tracking echocardiography has recently emerged as a quantitative ultrasound technique for accurately evaluating myocardial function by analyzing the motion of speckles identified on routine 2‐dimensional sonograms. It provides non‐Doppler, angle‐independent, and objective quantification of myocardial deformation and left ventricular systolic and diastolic dynamics. By tracking the displacement of the speckles during the cardiac cycle, strain and the strain rate can be rapidly measured offline after adequate image acquisition. Data regarding the feasibility, accuracy, and clinical applications of speckle‐tracking echocardiography are rapidly accumulating. This review describes the fundamental concepts of speckle‐tracking echocardiography, illustrates how to obtain strain measurements using this technique, and discusses their recognized and developing clinical applications.

Feasibility and reference values of left atrial longitudinal strain imaging by two-dimensional speckle tracking

BackgroundThe role of speckle tracking in the assessment of left atrial (LA) deformation dynamics is not established. We sought to determine the feasibility and reference ranges of LA longitudinal strain indices measured by speckle tracking in a population of normal subjects.MethodsIn 60 healthy individuals, peak atrial longitudinal strain (PALS) and time to peak longitudinal strain (TPLS) were measured using a 12-segment model for the left atrium. Values were obtained by averaging all segments (global PALS and TPLS) and by separately averaging segments measured in the two apical views (4- and 2-chamber average PALS and TPLS).ResultsAdequate tracking quality was achieved in 97% of segments analyzed. Inter and intra-observer variability coefficients of measurements ranged between 2.9% and 5.4%. Global PALS was 42.2 ± 6.1% (5–95° percentile range 32.2–53.2%), and global TPLS was 368 ± 30 ms (5–95° percentile range 323–430 ms). The 2-chamber average PALS was slightly higher than the 4-chamber average PALS (44.3 ± 6.0% vs 40.1 ± 7.9%, p < 0.0001), whereas no differences in TPLS were found (p = 0.93).ConclusionSpeckle tracking is a feasible technique for the assessment of longitudinal myocardial LA deformation. Reference ranges of strain indices were reported.

Early Detection of Left Atrial Strain Abnormalities by Speckle-Tracking in Hypertensive and Diabetic Patients with Normal Left Atrial Size

BACKGROUND Systemic hypertension and type 2 diabetes mellitus are associated with impaired left atrial (LA) function, but whether LA functional abnormalities also occur in patients with hypertension and diabetes who have normal LA sizes is unknown. The aim of this study was to explore LA strain using speckle-tracking echocardiography in patients with hypertension or diabetes and normal LA size. METHODS LA strain was studied by speckle-tracking echocardiography in 155 patients with hypertension or diabetes with LA volume indexes < 28 mL/m(2) (83 with hypertension, 34 with diabetes, and 38 with both diabetes and hypertension) and 36 age-matched controls. The following indexes were measured: peak atrial longitudinal strain, time to peak atrial longitudinal strain, atrial longitudinal strain during early diastole and late diastole, and peak LA strain rate during ventricular systole, early diastole, and late diastole. RESULTS Peak atrial longitudinal strain was lower in patients with hypertension (29.0 ± 6.5%) and those with diabetes (24.7 ± 6.4%) than in controls (39.6 ± 7.8%) and further reduced in patients with diabetes and hypertension (18.3 ± 5.0%) (P < .0001). Similar results were found for atrial longitudinal strain during early diastole, atrial longitudinal strain during late diastole, and peak LA strain rate during ventricular systole and early diastole (P < .0001 for all). An inverse trend was found for time to peak atrial longitudinal strain, whereas no differences in peak LA strain rate during late diastole were observed. Two-way analysis of variance showed no interactions between hypertension and diabetes. In multivariate analyses, hypertension and diabetes were both independently associated with decreases in all LA strain and strain rate indexes, with the exception of peak LA strain rate during late diastole. CONCLUSIONS LA deformation mechanics are impaired in patients with hypertension or diabetes with normal LA size. The coexistence of both conditions further impairs LA performance in an additive fashion. Speckle-tracking echocardiography may be considered a promising tool for the early detection of LA strain abnormalities in these patients.

Left atrial longitudinal strain by speckle tracking echocardiography correlates well with left ventricular filling pressures in patients with heart failure

BackgroundThe combination of early transmitral inflow velocity and mitral annular tissue Doppler imaging (E/Em ratio) is widely applied to noninvasively estimate left ventricular (LV) filling pressures. However E/Em ratio has a significant gray zone and its accuracy in patients with heart failure is debated. Left atrial (LA) deformation analysis by speckle tracking echocardiography (STE) was recently proposed as an alternative approach to estimate LV filling pressures. This study aimed at exploring the correlation of LA longitudinal function by STE and Doppler measurements with direct measurements of LV filling pressures in patients with heart failure.MethodsA total of 36 patients with advanced systolic heart failure (ejection fraction ≤35%), undergoing right heart catheterization, were studied. Simultaneously to pulmonary capillary wedge pressure (PCWP) determination, peak atrial longitudinal strain (PALS) and mean E/Em ratio were measured in all subjects by two independent operators. PALS values were obtained by averaging all segments (global PALS), and by separately averaging segments measured in the 4-chamber and 2-chamber views.ResultsNot significant correlation was found between mean E/Em ratio and PCWP (R = 0.15). A close negative correlation between global PALS and the PCWP was found (R = -0.81, p < 0.0001). Furthermore, global PALS demonstrated the highest diagnostic accuracy (AUC of 0.93) and excellent sensitivity and specificity of 100% and 93%, respectively, to predict elevated filling pressure using a cutoff value less than 15.1%. Bland-Altman analysis confirmed this close agreement between PCWP estimated by global PALS and invasive PCWP (mean bias 0.1 ± 8.0 mmHg).ConclusionIn a group of patients with advanced systolic heart failure, E/Em ratio correlated poorly with invasively obtained LV filling pressures. However, LA longitudinal deformation analysis by STE correlated well with PCWP, providing a better estimation of LV filling pressures in this particular clinical setting.

Left atrial deformation analysis by Speckle Tracking echocardiography for prediction of cardiovascular outcomes.

The incremental value of left atrial (LA) deformation analysis by speckle tracking echocardiography compared with LA volume or LA ejection fraction as a cardiovascular risk marker has not been evaluated prospectively. We sought to compare LA function by speckle tracking echocardiography to other conventional LA parameters for prediction of adverse cardiovascular outcomes. This prospective study included 312 adults (mean age 71 ± 6 years, 56% men) in sinus rhythm who were followed for development of first atrial fibrillation, congestive heart failure, stroke, transient ischemic attack, myocardial infarction, coronary revascularization, and cardiovascular death. Global peak atrial longitudinal strain (PALS) by speckle tracking echocardiography was measured in all subjects by averaging all atrial segments. Left atrium was assessed with biplane LA volume, LA ejection fraction, 4-chamber LA area, and M-mode dimension. Of 312 subjects at baseline, 43 had 61 new events during a mean follow-up of 3.1 ± 1.4 years. All LA parameters, traditional parameters, and parameters derived by speckle tracking echocardiography were independently predictive of combined outcomes (p <0.0001 for all comparisons). Overall performance for prediction of cardiovascular events was greatest for global PALS (area under receiver operator characteristic curve: global PALS 0.83, indexed LA volume 0.71, LA ejection fraction 0.69, LA area 0.64, LA diameter 0.59). A graded association between degree of LA enlargement and risk of cardiovascular events was evident only for global PALS and indexed LA volume. In conclusion, global PALS is a strong and independent predictor of cardiovascular events and appears to be superior to conventional parameters of LA analysis.

Novel echocardiographic techniques to assess left atrial size, anatomy and function

Three-dimensional echocardiography (3DE) and speckle tracking echocardiography (STE) have recently applied as imaging techniques to accurately evaluate left atrial (LA) size, anatomy and function. 3DE and off-line quantification softwares, have allowed, in comparison to magnetic resonance imaging, the most time-efficient and accurate method of LA volume quantification. STE provides a non-Doppler, angle-independent and objective quantification of LA myocardial deformation. Data regarding feasibility, accuracy and clinical applications of LA analysis by 3DE and STE are rapidly gathering. This review describes the fundamental concepts of LA 3DE and STE, illustrates how to obtain respective measurements and discuss their recognized and emerging clinical applications.

Chronic Mitral Regurgitation: Left Atrial Deformation Analysis by Two‐Dimensional Speckle Tracking Echocardiography

Background: Speckle tracking echocardiography (STE) is a novel method for the angle‐independent and objective quantification of myocardial deformation; it has recently evolved, enabling the quantification of longitudinal myocardial left atrial (LA) deformation dynamics. To investigate the effects of chronic mitral regurgitation (MR) on these functional atrial indices, we analyzed LA function by STE in a group of asymptomatic patients with chronic degenerative MR. Methods: The study population included 36 patients with mild MR, 38 with moderate MR, and 42 with severe MR. 52 age‐matched controls were also recruited. Global peak atrial longitudinal strain (global PALS) was measured in all subjects by averaging all atrial segments. Results: Age, gender, and LV ejection fraction in all pathological groups were comparable to those in the controls. Global PALS was higher in the mild MR group (46.7 ± 9.1%) in comparison with the controls (40.5 ± 6.2%; P < 0.001); instead global PALS was lower in the moderate MR group (25.7 ± 7.1%) and further reduced in the severe MR group (13.2 ± 5.2%) in comparison with the controls (40.5 ± 6.2%; overall P < 0.0001 by ANOVA, P < 0.05 for all pairwise comparisons). In multivariate analysis, E/Em ratio emerged as the principal independent determinant of global PALS. Conclusions: Our study provides new insight for the LA function analysis in response to different degrees of MR, showing that STE measurements of LA longitudinal strain may be considered a promising tool for the early detection of impairment of LA compliance in patients with asymptomatic chronic MR. (Echocardiography 2011;28:327‐334)

Endothelial Function in Pre-diabetes, Diabetes and Diabetic Cardiomyopathy: A Review

Diabetes mellitus worsens cardiovascular risk profile of affected individuals. Its worldwide increasing prevalence and its negative influences on vascular walls morphology and function are able to induce the expression of several morbidities which worsen the clinical conditions of the patients getting them running towards a reduced survival curve. Although overt diabetes increases the mortality rate of individuals due to its pathogenesis, poor information are in literature about the role of pre-diabetes and family history of diabetes mellitus in the outcome of general population. This emphasizes the importance of early detection of vascular impairment in subjects at risk of developing diabetes. The identification of early stages of atherosclerotic diseases in diabetic persons is a fundamental step in the risk stratification protocols followed-up by physicians in order to have a complete overview about the clinical status of such individuals. Common carotid intima-media thickness, flow-mediated vasodilatation, pulse wave velocity are instrumental tools able to detect the early impairment in cardiovascular system and stratify cardiovascular risk of individuals. The aim of this review is to get a general perspective on the complex relationship between cardiovascular diseases onset, pre-diabetes and family history of diabetes. Furthermore, it points out the influence of diabetes on heart function till the expression of the so-called diabetic cardiomyopathy.

Speckle tracking echocardiography as a new technique to evaluate right ventricular function in patients with left ventricular assist device therapy.

BACKGROUND Right ventricular (RV) systolic function has a critical role in determining the clinical outcome and the success of using left ventricular assist devices (LVADs) in patients with refractory heart failure. RV deformation analysis by speckle tracking echocardiography (STE) has recently allowed a deeper analysis of RV longitudinal function. The aim of the study was to observe RV function by STE in patients with advanced heart failure before and after LVAD implantation. METHODS Transthoracic echo Doppler was performed in 10 patients referred for LVAD therapy at baseline and with serial echocardiograms after LVAD implantation. In a sub-group of 4 patients, an echocardiographic evaluation was also made after intra-aortic balloon pump (IABP) support was initiated and before LVAD implantation. All echocardiographic images were analyzed off-line to calculate the free wall RV longitudinal strain (RVLS). RESULTS Three patients who presented the lowest free wall RVLS values at baseline, showed a progressive decline of RVLS after LVAD implant, presenting finally RV failure; however, patients with higher values of RVLS at baseline presented a further and overt increase of strain values in the course of follow-up. The overall performance for the prediction of RV failure after LVAD implant was greatest for free wall RVLS (area under the curve, 0.93). For the sub-group receiving the IABP as an intermediate step, only 2 patients with an increase of RVLS after IABP implantation also showed an increase of RVLS levels, after subsequent LVAD implantation. The 2 patients without an increase of RVLS after IABP implantation also presented with RV failure after LVAD therapy. CONCLUSIONS This study of 10 patients indicates that the new parameter of RVLS, representing RV myocardial deformation, may have important clinical implications for the selection and management of LVAD patients. A large multicenter study is required to confirm these observations and to quantify the clinical significance of changes in RVLS value.

Reference Values of Right Atrial Longitudinal Strain Imaging by Two‐Dimensional Speckle Tracking

Background: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. Methods: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six‐segment model for the RA. Strain rate (SR) was also measured starting from the QRS‐wave onset, peak positive (x‐wave), first peak negative (y‐wave), and second negative peak (z‐wave). The time from the QRS onset was measured to each wave peak. Results: Adequate tracking quality was achieved in 64% of segments analyzed. Inter‐ and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x‐wave was 2.12 ± 0.58 sec−1, y‐wave was −1.91 ± 0.63 sec−1, and z‐wave was −2.18 ± 0.78 sec−1. Conclusion: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported. (Echocardiography 2012;29:147‐152)