Speckle Tracking Echocardiography Analysis Research Articles

Assessment of Left Atrial Deformation and Function by 2-Dimensional Speckle Tracking Echocardiography in Healthy Dogs and Dogs With Myxomatous Mitral Valve Disease.

BackgroundThe assessment of left atrial (LA) function by 2‐dimensional speckle tracking echocardiography (STE) holds important clinical implications in human medicine. Few similar data are available in dogs.ObjectivesTo assess LA function by STE in dogs with and without myxomatous mitral valve disease (MMVD), analyzing LA areas, systolic function, and strain.AnimalsOne hundred and fifty dogs were divided according to the American College of Veterinary Internal Medicine classification of heart failure: 23 dogs in class A, 52 in class B1, 36 in class B2, and 39 in class C + D.MethodsProspective observational study. Conventional morphologic and Doppler variables, LA areas, and STE‐based LA strain analysis were performed in all dogs and results were compared among groups. Correlation analysis was carried out between LA STE variables and other echocardiographic variables.ResultsVariability study showed good reproducibility for all the tested variables (coefficient of variation <16%). Left atrial areas, fractional area change, peak atrial longitudinal strain (PALS), peak atrial contraction strain, and contraction strain index (CSI) differed significantly between groups B2 and C + D and all the other groups (overall P < .001), whereas only PALS differed between groups B1 and A (P = .01). Left atrial areas increased with progression of the disease, whereas LA functional parameters decreased. Only CSI increased nonsignificantly from group A to group B1 and then progressively decreased. Thirty‐one significant correlations (P < .001, r > .3) were found between conventional left heart echocardiographic variables and LA areas and strain variables.Conclusions and Clinical ImportanceLeft atrial STE analysis provides useful information on atrial function in the dog, highlighting a progressive decline in atrial function with worsening of MMVD.

Left ventricular longitudinal strain in soccer referees.

Along the years, the analysis of soccer referees perfomance has interested the experts and we can find several types of studies in literature using in particular cardiac imaging. The aim of this retrospective study was to observe relationship between VO2max uptake and some conventional and not-conventional echocardiographic parameters. In order to perform this evaluation, we have enrolled 20 referees, belonging to Italian Soccer Referees' Association and we have investigated cardiovascular profile of them. We found a strong direct relationship between VO2max and global longitudinal strain of left ventricle assessed by means of speckle tracking echocardiographic analysis (R2=0.8464). The most common classic echocardiographic indexes have showed mild relations (respectively, VO2max vs EF: R2=0.4444; VO2max vs LV indexed mass: R2=0.2268). Therefore, our study suggests that longitudinal strain could be proposed as a specific echocardiographic parameter to evaluate the soccer referees performance.

Global Longitudinal Strain or Left Ventricular Twist and Torsion? Which Correlates Best with Ejection Fraction?

BackgroundEstimative of left ventricular ejection fraction (LVEF) is a major indication for echocardiography. Speckle tracking echocardiography (STE) allows analysis of LV contraction mechanics which includes global longitudinal strain (GLS) and twist/torsion, both the most widely used. Direct comparison of correlations between these novel parameters and LVEF has never been done before.ObjectiveThis study aims to check which one has the highest correlation with LVEF.MethodsPatients with normal LVEF (> 0,55) and systolic dysfunction (LVEF <0,55) were prospectively enrolled, and underwent echocardiogram with STE analysis. Correlation of variables was performed by linear regression analysis. In addition, correlation among levels of LV systolic impairment was also tested.ResultsA total of 131 patients were included (mean age, 46 ± 14y; 43%, men). LVEF and GLS showed a strong correlation (r = 0.95; r2 = 0.89; p < 0.001), more evident in groups with LV systolic dysfunction than those with preserved LVEF. Good correlation was also found with global longitudinal strain rate (r = 0.85; r2 = 0.73; p < 0.001). Comparing to GLS, correlation of LVEF and torsional mechanics was weaker: twist (r = 0.78; r2 = 0.60; p < 0.001); torsion (r = 0.75; r2 = 0.56; p < 0.001).ConclusionGLS of the left ventricle have highly strong positive correlation with the classical parameter of ejection fraction, especially in cases with LV systolic impairment. Longitudinal strain rate also demonstrated a good correlation. GLS increments analysis of LV systolic function. On the other hand, although being a cornerstone of LV mechanics, twist and torsion have a weaker correlation with LV ejection, comparing to GLS.

Dynamic left ventricular changes in patients with gestational diabetes: A speckle tracking echocardiography study.

The left ventricle (LV) undergoes physiologic remodeling in adaptation to the hemodynamic changes that occur in pregnancy. Speckle tracking echocardiography (STE) is a novel and reliable tool to evaluate subtle myocardial alterations that have been utilized to assess myocardial changes in patients with diabetes mellitus (DM) but not in patients with gestational DM (GDM). We seek to evaluate changes in LV function using STE in patients with GDM compared with women with normal pregnancy. This was a single-center retrospective cohort study. A total of 312 pregnant patients that underwent transthoracic echocardiogram (TTE) between 2009 and 2014 were screened. After excluding patients with comorbidities or insufficient data, 90 women were included. TTE from the second and third trimester for each patient were then reviewed, and STE analysis was performed. Of the 90 subjects, 72 had normal pregnancies and 18 developed GDM. There was no difference in LV end-diastolic diameter (4.73 ± 0.40 versus 4.60 ± 0.56, p = 0.25), LV end-systolic diameter (3.12 ± 0.35 versus 2.91 ± 0.61, p = 0.152), or ejection fraction (62.26 ± 4.12 versus 63.50 ± 5.24, p = 0.314) between the two groups. Global longitudinal strain was lower (-19.8 ± 3.34 versus -17.2 ± 2.18, p < 0.001) in patients with GDM, while time-to-peak strain was greater (0.43 ± 0.05 versus 0.50 ± 0.06, p < 0.001). Circumferential and radial strains were preserved in both groups. Although conventional TTE variables show preserved LV size and function, LV longitudinal strain suggests subclinical myocardial dysfunction in patients with GDM. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:20-27, 2017.

Aortic Valve Disease and Vascular Mechanics: Two-Dimensional Speckle Tracking Echocardiographic Analysis.

Degenerative aortic valve disease (AVD) is a complex disorder that goes beyond valve itself, also undermining aortic wall. We aimed to assess the ascending aortic mechanics with two-dimensional speckle tracking echocardiography (2DSTE) in patients with aortic regurgitation (AR) and hypothesized a relationship with degree of AR. Aortic mechanics were then compared with those of similarly studied healthy controls and patients with aortic stenosis (AS); finally, we aimed to assess the prognostic significance of vascular mechanics in AVD. Overall, 73 patients with moderate-to-severe AR and 22 healthy subjects were enrolled, alongside a previously examined cohort (N = 45) with moderate-to-severe AS. Global circumferential ascending aortic strain (CAAS) and strain rate (CAASR) served as indices of aortic deformation; corrected CAAS was calculated as CAAS/pulse pressure (PP). Median clinical follow-up was 438 days. In patients with severe (vs. moderate) AR, CAASR (1.53 ± 0.29/sec vs. 1.90 ± 0.62/sec, P < 0.05) and corrected CAAS (0.14 ± 0.06%/mmHg vs. 0.19 ± 0.08%/mmHg, P < 0.05) were significantly lower, whereas CAAS did not differ significantly. Measurers of aortic mechanics (CAAS, corrected CAAS, CAASR) differed significantly (all P < 0.01) in patients with AS and AR and in healthy subjects, with lower values seen in patients with AS. In follow-up, survival rate of AVD patients with baseline CAASR >0.88/sec was significantly higher (log rank, 97.4% vs. 73.0%; P = 0.03). Quantitative measures of aortic mechanics were lower for AS patients, suggesting a more significant derangement of aortic elastic properties. In the context of AVD, vascular mechanics assessment proved useful in gauging clinical prognosis.

Abstract 14632: Effect of Obesity on Myocardial Strain Determined by Speckle Tracking Imaging

Introduction: Obesity may affect cardiac function, which is hard to detect by traditional echocardiography in the early stages. Speckle tracking imaging (STI) is sensitive to subtle myocardial dysfunction. The aim of this study was to determine the influence of obesity on left ventricular (LV) myocardial function in diet-induced obesity (DIO) mice using two-dimensional (2D) speckle tracking echocardiography (STE). Hypothesis: 2D STE is useful to detect obesity-caused myocardial dysfunction. Methods: Twenty newborn mice were divided into two groups: a DIO group (high-fat diet) and a control group (regular-fat diet). 2D image loops were acquired at the end of each month for 6 months. Global longitudinal strain (GLS) and global circumferential strain (GCS) were analyzed at feeding periods over 3 months and 6 months, and compared between the two groups. Results: The control group gained 64% of its initial weight, while the DIO group gained 82% of its initial weight at the 3 month feeding period; and the two groups gained 88% (control) and 125% (DIO) respectively at 6 months. STE analysis revealed an insignificant decrease in strain values in the DIO mice after 3 months; however, after 6 months, the DIO group demonstrated a significant decrease in strain values (P&lt;0.05) despite normal ejection fractions in both groups. Conclusions: 2D STE is highly feasible to detect the myocardial dysfunction caused by obesity in earlier stage. These strain values appear to be related to the severity of obesity.

Abstract 10876: Speckle-tracking vs. Pressure-Volume Loop Measures of Left Ventricular Systolic Function in Children: An Inter-vendor Comparison

Introduction: The variability in speckle-tracking echocardiography (STE) algorithms between vendors is well recognized. While some are attempting to standardize algorithms across vendors, it is currently unknown which algorithm best compares to gold-standard measures of systolic function. The objective of this study was to compare STE measures of deformation from two vendors vs. gold-standard measures of LV contractility and global ventricular efficiency in children. Methods: Children with normal loading conditions undergoing routine left heart catheterization were prospectively enrolled. Pressure-volume loops were obtained via conductance catheterization. The gold-standard measure of contractility, end-systolic elastance (Ees), was obtained via balloon occlusion of the vena cavae. Ventriculo-arterial coupling was assessed using the arterial elastance to Ees ratio (Ea/ Ees). STE was performed immediately after PVL analysis under the same anesthetic conditions. Offline STE analysis was perfomed using both QLAB v9.0 (Phillips, Andover, MA) and Cardiac Performance Analysis v3.0 (Tomtec, Hamden, CT) by a single blinded observer. The relationships between PVL and STE measures of systolic function were determined using Spearman’s correlation. Results: Of 24 patients, 18 patients were s/p heart transplant, 6 patients had a small patent ductus arteriosus or small coronary fistula. Mean age was 9.1 ± 5.6 years. The average invasive Ees was 3.04 ± 1.65 mmHg/mL. The average Ea/Ees was 0.88 ± 0.35. Correlations between invasive Ees and Ea/Ees to STE measures of deformation are reported in the Table. Conclusion: STE measures of GLS and GLSR derived from Cardiac Performance Analysis have better correlation with gold-standard measures of cardiac performance when compared to QLAB. GCS derived from both vendors has no correlation to invasive measures. Attempts to standardize STE algorithms should take these results into consideration.

Archeological Echocardiography: Digitization and Speckle Tracking Analysis of Archival Echocardiograms in the HyperGEN Study.

Several large epidemiologic studies and clinical trials have included echocardiography, but images were stored in analog format and these studies predated tissue Doppler imaging (TDI) and speckle tracking echocardiography (STE). We hypothesized that digitization of analog echocardiograms, with subsequent quantification of cardiac mechanics using STE, is feasible, reproducible, accurate, and produces clinically valid results. In the NHLBI HyperGEN study (N = 2234), archived analog echocardiograms were digitized and subsequently analyzed using STE to obtain tissue velocities/strain. Echocardiograms were assigned quality scores and inter-/intra-observer agreement was calculated. Accuracy was evaluated in: (1) a separate second study (N = 50) comparing prospective digital strain versus post hoc analog-to-digital strain, and (2) in a third study (N = 95) comparing prospectively obtained TDI e' velocities with post hoc STE e' velocities. Finally, we replicated previously known associations between tissue velocities/strain, conventional echocardiographic measurements, and clinical data. Of the 2234 HyperGEN echocardiograms, 2150 (96.2%) underwent successful digitization and STE analysis. Inter/intra-observer agreement was high for all STE parameters, especially longitudinal strain (LS). In accuracy studies, LS performed best when comparing post hoc STE to prospective digital STE for strain analysis. STE-derived e' velocities correlated with, but systematically underestimated, TDI e' velocity. Several known associations between clinical variables and cardiac mechanics were replicated in HyperGEN. We also found a novel independent inverse association between fasting glucose and LS (adjusted β = -2.4 [95% CI -3.6, -1.2]% per 1-SD increase in fasting glucose; P < 0.001). Archeological echocardiography, the digitization and speckle tracking analysis of archival echocardiograms, is feasible and generates indices of cardiac mechanics similar to contemporary studies.

Cardiac Function After the Immediate Transitional Period in Very Preterm Infants Using Speckle Tracking Analysis

The postnatal period in preterm infants involves multiple physiologic changes starting directly after birth and continuing for days or weeks. To recognize and treat compromise, it is important to measure cardiovascular function. We used a novel technique (speckle tracking echocardiography, STE) to measure cardiac function in this period. We obtained cardiac ultrasound images at day 3, 7, 14, 21 and 28 in preterm infants <30-week gestation. Conventional measures included cardiac size, left ventricular stroke volume, atrial volume and the patent ductus arteriosus (PDA). Four chamber images were analyzed with STE, which provided parameters of left ventricular volume, longitudinal deformation and myocardial velocities. Images of 54 infants (gestational age 23-29 weeks) were analyzed. STE-derived stroke volume correlated well with conventional echocardiography-derived stroke volume, but agreement was suboptimal. Most STE parameters showed good reliability. All volume parameters and systolic and atrial velocities increased over time. Cardiac deformation and early diastolic velocity did not change. A PDA was associated with 33 % increased stroke volume at day 3 up to 98 % at day 28 with a spherically enlarged heart and increased filling pressure. Speckle tracking echocardiography analysis is a feasible and reliable technique that can simultaneously obtain systolic and diastolic volumes, longitudinal deformation and myocardial velocities from one ultrasound window. Preterm hearts maintain cardiac function well during the first weeks of life, even with increased preload as a consequence of a PDA.

4-DIMENSIONAL STRAIN IMAGING OF THE RIGHT VENTRICLE USING SPECKLE-TRACKING ECHOCARDIOGRAPHY: APPLICATION OF A NOVEL DEFORMATION PARAMETER

Echocardiographic evaluation of right ventricular (RV) function is challenged by its asymmetric geometry. Two-dimensional (2D) RV strain imaging by speckle-tracking echocardiography (STE) has previously demonstrated feasibility and prognostic significance. Three-dimensional (3D) strain analysis is preferable because it is not slice-plane limited and provides vectored data in multiple orthogonal planes from a single acquisition. However, current 3D STE analysis software systems were designed for the more symmetrical geometry of the left ventricle. The purpose of this study was to demonstrate the feasibility of a novel 3D strain analysis approach for calculation of principal strain to characterize RV mechanical function. Twenty-eight patients underwent echocardiography inclusive of RV imaging acquired from standard transthoracic views with RV systolic function assessment using conventional 2D and 3D parameters. STE was performed by manual placement of endocardial RV contours from 3 echocardiographic views, and a 3D mesh model was generated using specialized software (Tomtec Imaging Systems, Germany). Off-line analysis was then performed using GIUSEPPE, a custom in-house made Matlab-based (Mathworks, USA) software. The 3D mesh model was then deformed according to the local velocity at each frame of the cardiac cycle. The deformed mesh elements allowed computation of contraction in the dominant direction, or peak principal strain amplitude (PPSA) (see Figure 1). Mean age of the study population was 49.8±14.6 years and 10 patients (36%) were female. RV chamber size and function by conventional echocardiographic assessment was normal for 20 patients (71%), while 4 (14%) had RV enlargement, 4 (14%) RV dysfunction and 3 (11%) RV hypertrophy. Mean RV end-diastolic volume, end-systolic volume, 3D ejection fraction (EF), 2D global peak longitudinal systolic strain (GLPSS) and tricuspid annular plane systolic excursion (TAPSE) were 70.4±23.5 mL, 35.2±13.1 mL, 49.8±9.6%, -22.5±7.1%, and 2.2±0.4 mm, respectively. RV 3D strain analysis was feasible in all subjects. Mean RV 3D PPSA was -25.0±3.5%. Correlation coefficients (p-value) for RV PPSA were significant with 3D EF (r=0.67, p<0.01), GLPSS (r=0.72, p<0.01) and TAPSE (r=0.68, p=0.02). In this pilot study we demonstrate the feasibility of 3D RV strain analysis by STE to characterize RV mechanical deformation using a novel software tool that is adaptable to the unique geometry of the RV. PPSA assessment by 3D RV strain correlated well with conventional measures of RV systolic function and represents a viable measure of global contractile deformation.

Effect of positive end-expiratory pressure on porcine right ventricle function assessed by speckle tracking echocardiography.

BackgroundRight ventricle (RV) dysfunction and hypotension can be induced by high levels of positive end-expiratory pressure (PEEP). We sought to determine in an animal model if a novel ultrasound analysis technique: speckle tracking echocardiography (STE), could determine deterioration in RV function induced by PEEP and to compare this to a conventional method of RV analysis: fractional area change (FAC). STE is a sensitive, angle-independent method for describing cardiac deformation (‘strain’) and is particularly useful in analyzing RV function as has been shown in pulmonary hypertension cohorts.MethodsTen pigs, 40-90 kg, anaesthetized, fully mechanically ventilated at 6 ml/kg were subject to step-wise escalating levels of PEEP at two-minute intervals (0, 5, 10, 15, 20, 25 and 30cmH20). Intracardiac echocardiography was used to image the RV as transthoracic and transesophageal echocardiography did not give sufficient image quality or flexibility. Off-line STE analysis was performed using Syngo Velocity Vector Imaging (Seimens Medical Solutions Inc., USA). STE systolic parameters are RV free wall strain (RVfwS) and strain rate (RVfwSR) and the diastolic parameter RV free wall strain rate early relaxation (RVfwSRe)ResultsWith escalating levels of PEEP there was a clear trend of reduction in STE parameters (RVfwS, RVfwSR, RVfwSRe) and FAC. Significant hypotension (fall in mean arterial blood pressure of 20 mmHg) occurred at approximately PEEP 15 cmH2O. Comparing RVfwS, RVfwSR and RVfwSRe values at different PEEP levels showed a significant difference at PEEP 0 cmH2O vs PEEP 10 cmH2O and above. FAC only showed a significant difference at PEEP 0 cmH2O vs PEEP 20 cmH2O and above. 30% of pigs displayed dyssychronous RV free wall contraction at the highest PEEP level reached.ConclusionsSTE is a sensitive method for determining RV dysfunction induced by PEEP and deteriorated ahead of a conventional assessment method: FAC. RVfwS decreased to greater extent compared to baseline than FAC, earlier in the PEEP escalation process and showed a significant decrease before there was a clinical relevant decrease in mean arterial blood pressure. Studies in ICU patients using transthoracic echocardiography are warranted to further investigate the most sensitive echocardiography method for detecting RV dysfunction induced by mechanical ventilation.

Left atrial strain predicts postoperative atrial fibrillation in patient undergoing major orthopaedic surgery

Background: Atrial fibrillation (AF) is an arrhythmia that often occurred in patients after orthopaedic surgery; the presence&lt;br /&gt;of AF affects prognosis and prolongs hospitalization of these patients. Speckle tracking echocardiography (STE) is a&lt;br /&gt;new echocardiographic technique that has recently shown to predict the occurrence of AF. The aim of this study was&lt;br /&gt;to investigate left atrial (LA) function by STE in patients undergoing orthopaedic surgery and to correlate results with the&lt;br /&gt;incidence of post-operative AF.&lt;br /&gt;Methods: One-hundred and fifteen patients (mean age 74±12 years), undergoing elective (n=39; 41.9%) or post-traumatic&lt;br /&gt;(n=54; 58.0%) orthopaedic surgery, were prospectively enrolled. Both conventional echocardiographic parameters and STE&lt;br /&gt;parameters were measured in all subjects the day before surgery. The occurrence of AF was monitored until discharge.&lt;br /&gt;Results: Of 115 patients screened, 93 met eligibility criteria; 49 underwent hip surgery, 28 knee surgery and 16 surgery of&lt;br /&gt;the shoulder/elbow. All patients received a standard postoperative care. No major surgical complications were recorded.&lt;br /&gt;Postoperative AF occurred in 26 patients (27.9%). Among all clinical and echocardiographic variables analyzed, global PALS&lt;br /&gt;demonstrated the highest diagnostic accuracy (AUC of 0.88) and, with a cutoff value less than 15.3%, good sensitivity and&lt;br /&gt;specificity of 89% and 90%, respectively, to predict postoperative AF episodes. LA volume indexed and E/e’ ratio had lower&lt;br /&gt;diagnostic accuracy (AUC 0.70 and 0.49, respectively).&lt;br /&gt;Conclusions: STE analysis of LA myocardial deformation could be considered a promising tool for the evaluation of AF risk&lt;br /&gt;prediction in patients undergoing orthopaedic surgery.

Speckle tracking echocardiography assessment of global and regional contraction dysfunction in the mice model of pressure overload.

Speckle tracking echocardiography (STE) has been applied to the evaluation of cardiac contraction dysfunction. However, there were few studies on alteration of global and regional STE parameters in the process of myocardial hypertrophy and heart failure. In this study, STE was applied to evaluate the global and regional cardiac function under heart failure and hypertrophy in the mice model of pressure overload. Adult mice were subjected to mild or severe aortic banding with a 25 Gauge (G) or 27 G needle. After surgery, STE and conventional echocardiography were used in the sham group (n=10), mild trans-aortic banding (TAB) group (n=14) and severe TAB group (n=10) for 8 weeks. The results showed that the mice subjected to severe TAB showed a significant change in fractional shortening (FS), left ventricular (LV) mass, and left ventricular end diastolic diameter (LVEDD) (P<0.05 for each). Meanwhile, there were no significant differences in FS and LVEDD between the sham group and mild TAB group during the experimental procedures (P>0.05 for both). STE analysis revealed that longitudinal strain (LS) was significantly decreased in the severe TAB group as compared with the sham and mild TAB groups (P<0.05 for both) from the postoperative week 1. LS in the mild TAB group was reduced as compared to the sham group (P<0.05). Radial strain (RS) and circumferential strain (CS) were significantly decreased in the severe TAB group as compared to the sham group and the mild TAB group (P<0.05 for both) from the postoperative week 1 (P<0.05 for both). Compared to the sham group, CS in the mild TAB group maintained unchanged during the test period, and RS was reduced only on the postoperative week 6 (P<0.05). Finally, regional contraction dysfunction was analyzed in both hypertrophic and failing myocardium in longitudinal and radial directions. It was found that LS was largest in the apex region and RS was smallest in the apex region in the healthy and hypertrophic myocardium. It was also found that compared to the sham group, only base longitudinal strain in the mild TAB group was decreased. Each of regional strain in the severe TAB group was uniformly depressed in radial and longitudinal directions. It is concluded that STE has provided a non-invasive and highly feasible way to explore the global and regional contraction dysfunction in hypertrophic and heart failure myocardium in the murine model of pressure overload.

The Relationship between Time from Myocardial Infarction, Left Ventricular Dyssynchrony, and the Risk for Ventricular Arrhythmia: Speckle-Tracking Echocardiographic Analysis

Differences in arrhythmogenic substrate may explain the variable efficacy of implantable cardioverter-defibrillators (ICDs) in primary sudden cardiac death prevention over time after myocardial infarction (MI). Speckle-tracking echocardiography allows the assessment left ventricular (LV) dyssynchrony, which may reflect the electromechanical heterogeneity of myocardial tissue. The aim of the present study was to evaluate the relationship among LV dyssynchrony, age of MI, and their association with the risk for ventricular tachycardia (VT) after MI. A total of 206 patients (median age, 67 years; 87% men) with prior MIs (median MI age, 6.2 years; interquartile range, 0.66-15 years) who underwent programmed electrical stimulation, speckle-tracking echocardiography, and ICD implantation were retrospectively evaluated. LV dyssynchrony was defined as the standard deviation of time to peak longitudinal systolic strain values using speckle-tracking strain echocardiography. LV scar burden was evaluated by the percentage of segments exhibiting scar (defined as an absolute longitudinal strain of magnitude < 4.5%). Patients were followed up for the occurrence of first monomorphic VT requiring ICD therapy (antitachycardia pacing or shock) for a median of 24 months. In total, 75 individuals experienced the primary end point of monomorphic VT. LV dyssynchrony was independently associated with the occurrence of VT at follow-up (hazard ratio per 10-msec increase, 1.12; 95% confidence interval, 1.07-1.18; P < .001), together with nonrevascularization of the infarct-related artery and VT inducibility. Patients with older (>180 months) MIs had a higher likelihood of VT inducibility (88% vs 63%, P = .003) and greater scar burden (14.7 ± 15.8% vs 10.7 ± 11.4%, P = .03) compared with patients with recent (<8 months) MIs. LV dyssynchrony is independently associated with the occurrence of VT after MI.

Strain and strain rate by speckle-tracking echocardiography correlate with pressure-volume loop-derived contractility indices in a rat model of athlete's heart.

Contractile function is considered to be precisely measurable only by invasive hemodynamics. We aimed to correlate strain values measured by speckle-tracking echocardiography (STE) with sensitive contractility parameters of pressure-volume (P-V) analysis in a rat model of exercise-induced left ventricular (LV) hypertrophy. LV hypertrophy was induced in rats by swim training and was compared with untrained controls. Echocardiography was performed using a 13-MHz linear transducer to obtain LV long- and short-axis recordings for STE analysis (GE EchoPAC). Global longitudinal (GLS) and circumferential strain (GCS) and longitudinal (LSr) and circumferential systolic strain rate (CSr) were measured. LV P-V analysis was performed using a pressure-conductance microcatheter, and load-independent contractility indices [slope of the end-systolic P-V relationship (ESPVR), preload recruitable stroke work (PRSW), and maximal dP/dt-end-diastolic volume relationship (dP/dtmax-EDV)] were calculated. Trained rats had increased LV mass index (trained vs. control; 2.76 ± 0.07 vs. 2.14 ± 0.05 g/kg, P < 0.001). P-V loop-derived contractility parameters were significantly improved in the trained group (ESPVR: 3.58 ± 0.22 vs. 2.51 ± 0.11 mmHg/μl; PRSW: 131 ± 4 vs. 104 ± 2 mmHg, P < 0.01). Strain and strain rate parameters were also supernormal in trained rats (GLS: -18.8 ± 0.3 vs. -15.8 ± 0.4%; LSr: -5.0 ± 0.2 vs. -4.1 ± 0.1 Hz; GCS: -18.9 ± 0.8 vs. -14.9 ± 0.6%; CSr: -4.9 ± 0.2 vs. -3.8 ± 0.2 Hz, P < 0.01). ESPVR correlated with GLS (r = -0.71) and LSr (r = -0.53) and robustly with GCS (r = -0.83) and CSr (r = -0.75, all P < 0.05). PRSW was strongly related to GLS (r = -0.64) and LSr (r = -0.71, both P < 0.01). STE can be a feasible and useful method for animal experiments. In our rat model, strain and strain rate parameters closely reflected the improvement in intrinsic contractile function induced by exercise training.

Evaluation of right ventricle by speckle tracking and conventional echocardiography in rats with right ventricular heart failure.

Speckle tracking echocardiography (STE) has been reported to be a promising technique for evaluating right ventricular (RV) function in the clinical setting. On the other hand, the usefulness of STE for RV evaluation in small animal models has not been clarified, although the rat model is among the most commonly used animal models to develop novel effective treatments against pulmonary hypertension and RV heart failure (HF).We validated the use of STE and conventional echocardiographic variables for evaluating RV functions in a rat model by comparing the echocardiographic values of RVHF rats (n = 12) induced by monocrotaline injection with those of control rats (n = 12).Most conventional echocardiographic variables demonstrated that RVHF rats have significant RV dysfunction. The area under the curve (AUC) values to distinguish RV dysfunction in RVHF rats from normal RV function in control rats using fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), RV myocardial performance index (MPI), peak tissue Doppler tricuspid annular velocities at systole (Sa), and at early diastole (Ea) were 0.71, 0.98, 0.79, 0.92, and 0.91, respectively. However, using STE analysis for RV evaluation, limited reproducibility was observed (variability 19-37 %, ICC 0.74-0.88) and the only circumferential strain showed significantly lower absolute values (P = 0.039, AUC = 0.76).To evaluate RV function in rat models, circumferential strain may be useful, however, the reproducibility and diagnostic utility were limited. Conventional echocardiographic variables such as TAPSE, tissue Doppler Sa, and Ea have superior diagnostic utility.

Quality Control and Reproducibility in M-Mode, Two-Dimensional, and Speckle Tracking Echocardiography Acquisition and Analysis: The CARDIA Study, Year 25 Examination Experience.

Few large studies describe quality control procedures and reproducibility findings in cardiovascular ultrasound, particularly in novel techniques such as speckle tracking echocardiography (STE). We evaluate the echocardiography assessment performance in the Coronary Artery Risk Development in Young Adults (CARDIA) study Year 25 (Y25) examination (2010-2011) and report findings from a quality control and reproducibility program conducted to assess Field Center image acquisition and reading center (RC) accuracy. The CARDIA Y25 examination had 3475 echocardiograms performed in 4 US Field Centers and analyzed in a RC, assessing standard echocardiography (LA dimension, aortic root, LV mass, LV end-diastolic volume [LVEDV], ejection fraction [LVEF]), and STE (two- and four-chamber longitudinal, circumferential, and radial strains). Reproducibility was assessed using intraclass correlation coefficients (ICC), coefficients of variation (CV), and Bland-Altman plots. For standard echocardiography reproducibility, LV mass and LVEDV consistently had CV above 10% and aortic root below 6%. Intra-sonographer aortic root and LV mass had the most robust values of ICC in standard echocardiography. For STE, the number of properly tracking segments was above 80% in short-axis and four-chamber and 58% in two-chamber views. Longitudinal strain parameters were the most robust and radial strain showed the highest variation. Comparing Field Centers with echocardiography RC STE readings, mean differences ranged from 0.4% to 4.1% and ICC from 0.37 to 0.66, with robust results for longitudinal strains. Echocardiography image acquisition and reading processes in the CARDIA study were highly reproducible, including robust results for STE analysis. Consistent quality control may increase the reliability of echocardiography measurements in large cohort studies.

Feasibility of radial and circumferential strain analysis using 2D speckle tracking echocardiography in cats.

The purpose of the present study is to investigate the feasibility of strain analysis using speckle tracking echocardiography (STE) in cats and to evaluate STE variables in cats with hypertrophic cardiomyopathy (HCM). Sixteen clinically healthy cats and 17 cats with HCM were used. Radial and circumferential strain and strain rate variables in healthy cats were measured using STE to assess the feasibility. Comparisons of global strain and strain variables between healthy cats and cats with HCM were performed. Segmental assessments of left ventricle (LV) wall for strain and strain rate variables in cats with HCM were also performed. As a result, technically adequate images were obtained in 97.6% of the segments for STE analysis. Sedation using buprenorphine and acepromazine did not affect any global strain nor strain rate variable. In LV segments of cats with HCM, reduced segmental radial strain and strain rate variables had significantly related with segmental LV hypertrophy. It is concluded that STE analysis using short axis images of LV appeared to be clinically feasible in cats, having the possibility to be useful for detecting myocardial dysfunctions in cats with diseased heart.

Acute impact of pacing at different cardiac sites on left ventricular rotation and twist in dogs.

ObjectivesWe evaluated the acute impact of different cardiac pacing sites on two-dimensional speckle-tracking echocardiography (STE) derived left ventricular (LV) rotation and twist in healthy dogs.MethodsTwelve dogs were used in this study. The steerable pacing electrodes were positioned into right heart through the superior or inferior vena cava, into LV through aorta across the aortic valve. The steerable pacing electrodes were positioned individually in the right atrium (RA), right ventricular apex (RVA), RV outflow tract (RVOT), His bundle (HB), LV apex (LVA) and LV high septum (LVS), individual pacing mode was applied at 10 minutes interval for at least 5 minutes from each position under fluoroscopy and ultrasound guidance and at stabilized hemodynamic conditions. LV short-axis images at the apical and basal levels were obtained during sinus rhythm and pacing. Offline STE analysis was performed. Rotation, twist, time to peak rotation (TPR), time to peak twist (TPT), and apical-basal rotation delay (rotational synchronization index, RSI) values were compared at various conditions. LV pressure was monitored simultaneously.ResultsAnesthetic death occurred in 1 dog, and another dog was excluded because of bad imaging quality. Data from 10 dogs were analyzed. RVA, RVOT, HB, LVA, LVS, RARV (RA+RVA) pacing resulted in significantly reduced apical and basal rotation and twist, significantly prolonged apical TPR, TPT and RSI compared to pre-pacing and RA pacing (all P<0.05). The apical and basal rotation and twist values were significantly higher during HB pacing than during pacing at ventricular sites (all P<0.05, except basal rotation at RVA pacing). The apical TPR during HB pacing was significantly shorter than during RVOT and RVA pacing (both P<0.05). The LV end systolic pressure (LVESP) was significantly lower during ventricular pacing than during pre-pacing and RA pacing.ConclusionsOur results show that RA and HB pacing results in less acute reduction on LV twist, rotation and LVESP compared to ventricular pacing.

Three-dimensional speckle tracking echocardiographic analysis of a fetal heart with hypoplastic left heart syndrome — A case from the MAGYAR-Fetus Study

Hypoplastic left heart syndrome (HLHS) is one of the cardiac malformations that probably result from multiple developmental errors in the early stages of cardiogenesis. The most important findings are enlarged cardiac silhouette with prominent right atrium and right ventricle (RV), pulmonary venous hypertension, atrial septal defect, valvular stenosis or atresia and underdeveloped or too small left ventricle (LV) and ascending aorta [1,2]. Three-dimensional (3D) speckle tracking echocardiography (STE) is a new promising non-invasive clinical tool, which incorporates benefits of STE and 3D echocardiography allowing volumetric chamber quantifications and deformation measurements at the same time from a 3D data acquisition [3].