Speckle Tracking Strain Imaging Research Articles

Discontinuous contraction in the left ventricle assessed by 2-D speckle tracking echocardiography benefits from CRT.

Cardiac resynchronization therapy (CRT) improves the morbidity and mortality rate in patients with left bundle-branch block (LBBB); however, some LBBB patients are non-responders for CRT. Previous studies have shown that a transmural functional line block alters the left ventricular (LV) activation sequence, and that the presence of a line block is predictive for responders. We investigated whether responders could be predicted in patients with LBBB by 2-dimensional (2-D) speckle tracking strain imaging. We enrolled 54 patients with LBBB, who underwent echocardiography before and 6 months after CRT implantation. A responder was defined by a decrease in the LV end-systolic volume>15% at the 6-month follow-up. We calculated a difference in the time from QRS onset to maximum strain between adjacent segments and defined the Tmax-diff as the maximum difference among six intersegments. We compared the Tmax-diff between responders and non-responders. Among 54 patients, 37 patients were identified as responders. The Tmax-diff of the responders was significantly longer than that of the non-responders (309.6 ± 168.6ms vs 181.5 ± 138.4ms, P=.009). Furthermore, Tmax-diff ≥ 195ms was higher in the septal and the anterior area. And patients with a Tmax-diff ≥ 195ms tended to be responders (P=.02). The present study showed that discontinuous contraction of the LV could be detected in CRT responders by 2-D speckle tracking strain imaging, which may be a useful tool to identify the contraction pattern of patients with LBBB and predict CRT responders.

Abstract 720: Prenatal Exposure of Cigarette Smoke Impacts Cardiac Regeneration

Background: Neonatal mammalian hearts have the unique characteristic to fully repair and regenerate following injury. This discovery has led to visionary endeavors to understand and subsequently reawaken regeneration processes in the human adult heart that are lost after birth, contributing to heart failure and death after ischemic insults. In utero exposure to tobacco smoke has detrimental effects on fetal development and growth. However, the consequences of prenatal exposure to cigarette smoke on murine neonate’s cardiac regeneration have never been explored. Methods: To study the impact of cigarette smoke during the entire pregnancy on cardiac regeneration in the offspring, plugged female wild type C57LB/6J mice were exposed either to cigarette smoke (n=6) or filtered air (control, n=6). Two days after birth, 5 pups from each litter were assigned to the two experimental groups: Myocardial infarction (MI) and sham. Detrimental effects of in utero exposure to tobacco smoke on the recovery of cardiac function following MI surgery were followed using two-dimensional speckle tracking echocardiography and strain imaging. To investigate the underlying mechanism, cardiac tissue of the infarct and remote zone was collected for non-coding RNA analysis. Results: In utero exposure to cigarette smoke significantly compromised cardiac regeneration in neonates. At both early and late time points in the phase of cardiac repair, hearts of neonates exposed to cigarette smoke during pregnancy showed a marked impairment of cardiac regenerative potential. In particular, ejection fraction, fractional area change and shortening, as well as left ventricular internal diameter during systole remained pathologically changed following MI insult in the smoked group until the very endpoint. Conclusions: Collectively, we here provide evidence that in utero exposure to cigarette smoke strongly compromises cardiac regeneration in the newborn offspring. This result reinforces smoking cessation during pregnancy. Additionally, understanding the changes in non-coding RNA expression in a setting of preserved versus disrupted repair of the heart might be an important first step towards the identification of key cellular processes in cardiac regeneration after injury.

Regional Left Ventricular Myocardial Dysfunction After Cardiac Surgery Characterized by 3-Dimensional Strain.

Three-dimensional (3D) strain is an echocardiographic modality that can characterize left ventricular (LV) function with greater accuracy than ejection fraction. While decreases in global strain have been used to predict outcomes after cardiac surgery, changes in regional 3D longitudinal, circumferential, radial, and area strain have not been well described. The primary aim of this study was to define differential patterns in regional LV dysfunction after cardiac surgery using 3D speckle tracking strain imaging. Our secondary aim was to investigate whether changes in regional strain can predict postoperative outcomes, including length of intensive care unit stay and 1-year event-free survival. In this prospective clinical study, demographic, operative, echocardiographic, and clinical outcome data were collected on 182 patients undergoing aortic valve replacement, mitral valve repair or replacement, coronary artery bypass graft, and combined cardiac surgery. Three-dimensional transthoracic echocardiograms were performed preoperatively and on the second to fourth postoperative day. Blinded analysis was performed for LV regional longitudinal, circumferential, radial, and area strain in the 17-segment model. Regional 3D longitudinal, circumferential, radial, and area strains were associated with differential patterns of myocardial dysfunction, depending on the surgical procedure performed and strain measure. Patients undergoing mitral valve repair or replacement had reduced function in the majority of myocardial segments, followed by coronary artery bypass graft, while patients undergoing aortic valve replacement had reduced function localized only to apical segments. After all types of cardiac surgery, segmental function in apical segments was reduced to a greater extent as compared to basal segments. Greater decrements in regional function were seen in circumferential and area strain, while smaller decrements were observed in longitudinal strain in all surgical patients. Both preoperative regional strain and change in regional strain preoperatively to postoperatively were correlated with reduced 1-year event-free survival, while postoperative strain was not predictive of outcomes. Only preoperative strain values were predictive of intensive care unit length of stay. Changes in regional myocardial function, measured by 3D strain, varied by surgical procedure and strain type. Differences in regional LV function, from presurgery to postsurgery, were associated with worsened 1-year event-free survival. These findings suggest that postoperative changes in myocardial function are heterogeneous in nature, depending on the surgical procedure, and that these changes may have long-term impacts on outcome. Therefore, 3D regional strain may be used to identify patients at risk for worsened postoperative outcomes, allowing early interventions to mitigate risk.

STRAIN ASSESSMENT OF THE ASCENDING AORTA IN PATIENTS WITH SEVERE AORTIC STENOSIS

Two-dimensional (2D) speckle-tracking strain imaging is an adjunct to standard 2D echocardiography. While strain assessment for left ventricular systolic function is commonly used, studies have suggested measuring strain in other cardiac structures. We compared circumferential strain of the

The Value of Speckle Tracking Strain Imaging at Recovery Period of Dobutamine Stress Echocardiography

Background: Dobutamine stress echocardiography (DSE) is a well-established method for detecting myocardial ischemia. The classic echocardiographic findings of ischemia are new or worsening abnormalities of radial wall thickening. However, interpretation of these findings is subjective and dependent on experience. Speckle tracking strain imaging (STI) has been introduced as a novel method to overcome these limitations. Objective: The aim of the study is to evaluate the value of speckle tracking imaging (STI) by estimating the mean global longitudinal systolic (GLS) and the mean global circumferential systolic (GCS) strain imaging at recovery period of dobutamine stress echocardiography for prediction of significant coronary artery disease (CAD) in patients with chest discomfort. Methods: Fifty three patients presented for evaluation of chest discomfort underwent dobutamine stress echocardiography and coronary angiography at Cardiology Department,Menoufia University Hospital. The mean global left ventricular longitudinal systolic strain (GLS) at apical views—3 chambers, 4 chambers & 2 chambers apical views and global left ventricular circumferential systolic strain (GCS) at short axis view at level of papillary muscle were measured at rest and during recovery period of dobutamine stress echocardiography using automated functional imaging (AFI). Coronary angiography was done for all patients. Significant coronary artery lesion was defined as having a ≥ 70% diameter stenosis on coronary angiography. Patients were divided into two groups based on the presence or absence of significant coronary artery lesion into CAD positive (+ve) group vs. CAD negative (-ve) group. Results: In both groups,there were no statistically significant differences in the clinical characteristics and baseline conventional transthoracic echocardiography. GLS and GSC at recovery were lower in the CAD (+ve) group than in the CAD (-ve) group (-16.69% ± 1.10% vs -19.05% ± 1.41% p ). GLS and GCS during recovery period of DSE were valuable for prediction of CAD when cutoff at recovery is less than -17.95% (sensitivity of 84% & specificity of 84%) for GLS and less than -20.2% (sensitivity of 76% & specificity of 84%) for GCS. Also, we observed that the GLS and GCS percentile decreased from baseline to recovery period of DSE by about -9.95% ± 4.82% and -7.72% ± 3.90% respectively. Conclusion: Speckle tracking Imaging GLS and GCS at recovery period of Dobutamine Stress Echocardiography is feasible and offers an objective technique for prediction of significant coronary artery disease with increasing the accuracy of DSE in patient with chest discomfort.

Left atrial deformation analysis as a predictor of severity of coronary artery disease.

BackgroundTwo-dimensional (2D) speckle-tracking strain imaging is a novel method for assessment of regional myocardial deformation that uses tracking of acoustic speckles or kernels rather than Doppler myocardial velocities. It has been suggested that Left atrial (LA) strain as measured by 2D speckle tracking can be used to evaluate dynamic LA function.ObjectiveTo study the relation between left atrial deformation and the severity of coronary artery stenosis in patients with stable coronary artery disease (CAD).Study design30 patients with stable coronary artery disease (SCAD) with coronary artery stenosis (>50%) who were admitted for elective coronary angiography at Ain Shams University hospitals and AlAzhar University hospitals were included in the study. Measurements of conventional echocardiographic parameters as well as LA strain and strain rate parameters were obtained, Syntax (SX) score was calculated for all patients.ResultsPatients were categorized into 3 groups: low Syntax score of <23 (Group I), moderate syntax score 23–32 (Group II) and high syntax score of ≥33 (Group III). Peak atrial longitudinal strain (PALS) (Group I: 29.80 ± 4.48, Group II: 22.44 ± 1.42, Group III: 19.53 ± 4.46; p < 0.001) and Peak atrial contraction strain (PACS) (Group I: 13.43 ± 4.05, Group II: 10.84 ± 2.47, Group III: 7.19 ± 0.71; p < 0.022) were significantly lower in high syntax group. Significant negative correlation was found between SX score level and LA strain parameters (PALS and PACS) (r = 0.861; p < 0.001).ConclusionLeft atrial deformation analysis by 2D Speckle tracking Doppler Echocardiography can predict the severity of coronary affection in patients with stable CAD.

5022Alterations in left atrial mechanics by speckle-tracking strain imaging in patients with Fabry disease

5022Alterations in left atrial mechanics by speckle-tracking strain imaging in patients with Fabry disease

Assessing Impact of High-Dose Pitavastatin on Carotid Artery Elasticity with Speckle-Tracking Strain Imaging.

Aim: Speckle-tracking imaging has been introduced for the precise assessment of vessel mechanics. However, there are no data on the role of this imaging tool in assessing the changes in vasculature with statin therapy, which is known to enhance vascular elasticity.Methods: This study was a prospective study including 48 statin-naïve patients (age, 58.2 ± 8.4 years; 29.2% male) with hypercholesterolemia. Circumferential carotid artery strain (CAS) and stiffness index (β2) were measured using speckle-tracking imaging before and after 3 months of high-dose pitavastatin treatment (4 mg daily). For the comparison, we measured conventional carotid elasticity parameters and intima–media thickness using B-mode ultrasound at the same time points.Results: Compared with baseline, there was significant improvement in circumferential CAS (2.98% ± 1.18% to 3.40% ± 1.43%, p = 0.008) and β2 (0.19 ± 0.07 to 0.17 ± 0.08, p = 0.047) after statin therapy. Contrariwise, there were no significant changes in all conventional carotid elasticity metrics and intima–media thickness. When stratifying patients into two subgroups by 10 year atherosclerotic cardiovascular disease (ASCVD) risk, speckle-tracking-derived circumferential CAS and β2 improved significantly only in patients with ASCVD risk ≥ 7.5%.Conclusions: Short-term treatment with high-dose pitavastatin improved carotid artery elasticity measured by speckle-tracking method, but not conventional parameters by B-mode ultrasound. Speckle-tracking-based measurements may allow the early noninvasive assessment of statin effects on vascular function in hypercholesterolemic patients.Abbreviations: CAS: carotid artery strain, β1: classic stiffness index, β2: speckle-tracking-derived stiffness index, IMT: intima-media thickness, ASCVD: atherosclerotic cardiovascular disease, CHD: coronary heart disease, LCL-C: low-density lipoprotein cholesterol, HDL-C: high-density lipoprotein cholesterol, CCA: common carotid artery

End-Stage Renal Disease Impairs the Multidirectional Movements of the Common Carotid Artery: Assessment Using Dimensional Speckle-Tracking Carotid Strain Ultrasonography.

BACKGROUNDArterial stiffening is a major contributing factor in the development of cardiovascular disease in patients with end-stage renal disease (ESRD). However, there is no gold standard for evaluating arterial stiffness. This study aimed to evaluate the newly developed speckle-tracking carotid strain imaging method in assessing arterial stiffness in patients with ESRD.METHODSIn total, 85 patients with normal renal function (controls) and 36 with ESRD were enrolled in this single-center study. Carotid B-mode ultrasonography was performed for all patients. Arterial stiffness indices and strain parameters of the common carotid arteries were analyzed. Values were compared between the groups, and multivariate linear regression analysis was performed to assess the impact of ESRD on carotid strain.RESULTSThere were no differences in the intima-media thickness, β stiffness index, and arterial compliance, but arterial distensibility was lower, and the elastic modulus and pulse wave velocity β (PWV) were higher among patients with ESRD (all p < 0.05), whether assessed in the longitudinal or transverse plane. Both longitudinal and transverse strain rates were reduced in patients with ESRD (all p < 0.05). In multivariate analyses, ESRD independently reduced both transverse radial strain and strain rate (all p < 0.05), and the transverse circumferential strain and strain rate (p < 0.05). However, all conventional aortic stiffness indices and longitudinal strain parameters were not associated with ESRD.CONCLUSIONSSpeckle-tracking carotid strain ultrasonography was successfully performed in both normal subjects and patients with ESRD. Multidirectional carotid strain analyses may provide more value than conventional aortic stiffness indices for risk stratification in patients with ESRD.

Worsening in Longitudinal Strain and Strain Rate Anticipates Development of Pediatric Transplant Coronary Artery Vasculopathy as Soon as OneYear Following Transplant.

Transplant coronary artery vasculopathy (TCAV) following orthotopic heart transplantation (OHT) continues to be the primary reason for late graft failure in children. The current gold standard of diagnosis of TCAV is coronary angiography with or without intravascular ultrasound. This study investigates the longitudinal use of speckle-tracking echocardiographic strain imaging as an early non-invasive marker to screen for development of TCAV. Echocardiograms from patients who underwent OHT between 2006 and 2010 at Children's Hospital Colorado (n=50) were retrospectively assessed. Studies were evaluated at baseline (within a month of transplant), then at each annual clinical follow-up for peak longitudinal (LS) and circumferential (CS) strain, systolic strain rate, and diastolic strain rate using Siemens Velocity Vector Imaging software. Comparisons were made between subjects who did and did not develop TCAV. Mean time to TCAV diagnosis following OHT was 3.2years (range 1-5.1years). One year after transplant, significant differences were seen between groups in LS (non-TCAV mean -19.6%, TCAV mean -17.3%, p=0.03) and longitudinal strain rate (non-TCAV mean -1.7%/s, TCAV mean -1.4%/s, p=0.04). These differences persisted in subsequent years. Differences in LS preceded the catheterization-based diagnosis of TCAV in pediatric heart recipients and were noted as early as one year post transplant. Additionally, within-subject LS changes may have utility as a non-invasive screening tool to predict those patients at increased risk for development of TCAV.

SY12-1 - Role of Echocardiographic Strain Imaging for Patients With Heart Failure

The risk stratification of patients with heart failure (HF) can be performed using echocardiographic parameters such as left ventricular (LV) ejection fraction (LVEF). Since LVEF reflects merely the change in LV volume but does not take into consideration ultrastructural changes that may occur at the myocardial level and that may impair LV systolic performance. Thus, LVEF may not truly represent LV systolic function in specific cardiac diseases or when subtle LV systolic dysfunction is present. Two-dimensional speckle-tracking is a post-processing computer algorithm that uses the routine grayscale digital images, and enables assessment of myocardial strain, thereby providing detailed information on global and regional active LV deformation. Global longitudinal strain (GLS), which was defined as the average peak strain of 18 segments from standard apical views, provides the best evidence on the diagnostic and prognostic implications, and the ability of GLS to predict cardiovascular outcome may be superior to LVEF. This presentation reviews the strengths of echocardiographic speckle-tracking strain imaging, especially GLS, and its current potential for clinical use in patients with HF.

Strain Imaging Detects Dose-Dependent Segmental Cardiac Dysfunction in the Acute Phase After Breast Irradiation

We examined the utility of echocardiographic 2-dimensional speckle tracking strain imaging (SI) for the evaluation of segmental myocardial dysfunction before and after radiation therapy (RT) and the relationship to dose exposure. We prospectively recruited 40 women with left-sided breast cancer, undergoing only adjuvant RT to the left chest. Comparisons of traditional echocardiographic parameters and SI parameters at baseline and 6weeks after RT were analyzed.Regional strain and strain rate (SR) parameters were obtained from all 18 left ventricular segments. The correlation of change in strain parameters with segmental radiation dose was examined. We observed a significant reduction in global and segmental systolic strain parameters at 6weeks after RT compared with baseline, with the largest decrement in the apical segments; this corresponded with the segments receiving the highest radiation dose exposure (apical peak systolic strain of -21.21%±3.49% before RT vs -18.69%±3.34% after RT, percentage change of 11.88%, P=.002; apical peak systolic SR of -1.17±0.24s-1 before RT vs -1.04±0.19s-1 after RT, percentage change of 11.11%, P=.008). There was a modest correlation between the apical segment systolic strain reduction and radiation dose exposure (apical segment Δ change and apical radiation dose, r=0.345, P=.031; apical segment percentage change and apical radiation dose, r=0.346, P=.031). A significant reduction in early diastolic SR was observed in the apical segments after treatment compared with baseline (apical early diastolic SR, 1.54±0.45s-1 before RT vs 1.35±0.33 after RT s-1; percentage change, 12.34%; P=.034). Two-dimensional SI detected dose-related regional myocardial dysfunction in the acute phase after RT in chemotherapy-naive left-sided breast cancer patients. Although the long-term effects remain unknown, this imaging modality may have a potential role in the evaluation of irradiation-related cardiotoxicity.

Preoperative Three-Dimensional Strain Imaging Identifies Reduction in Left Ventricular Function and Predicts Outcomes After Cardiac Surgery.

Echocardiography-based speckle-tracking strain imaging is an emerging modality to assess left ventricular function. The aim of this study was to investigate the change in left ventricular systolic function after cardiac surgery with 3-dimensional (3D) speckle-tracking strain imaging and to determine whether preoperative 3D strain is an independent predictor of acute and long-term clinical outcomes after aortic valve, mitral valve, and coronary artery bypass grafting operations. In total, 163 adult patients undergoing aortic valve, mitral valve, and coronary artery bypass surgeries were enrolled prospectively and had complete data sets. Demographic, operative, and outcome data were collected. 3D transthoracic echocardiograms were preformed preoperatively and on second to fourth postoperative day. Blinded off-line analysis was performed for left ventricular 2-dimensional (2D) ejection fraction (EF2D) and 3D ejection fraction (EF3D) and global peak systolic area, longitudinal, circumferential, and radial strain. 3D global strain correlated well with EF3D. Ventricular function as measured by strain imaging decreased significantly after all types of cardiac surgery. When preoperative EF3D was used, receiver operating characteristic curves identified reference values for 3D global strain corresponding to normal, mildly reduced, and severely reduced ventricular function. Normal ventricular function (EF3D ≥ 50%) corresponded to 3D global area strain -25%, with area under curve = 0.86 (0.81-0.89). Patients with reduced preoperative 3D global area strain had worse postoperative outcomes, including length of intensive care unit stay (4 vs 3 days, P = .001), major adverse events (27% vs 11%, P = .03), and decreased 1-year event-free survival (69% vs 88%, P = .005). After we controlled for baseline preoperative risk models including European System for Cardiac Operative Risk Evaluation score and surgery type, preoperative strain was an independent predictor of both short- and long-term outcomes, including length of intensive care unit stay, postoperative inotrope score, and 1-year event-free survival. This study shows that cardiac surgery was associated with an acute reduction in postoperative left ventricular function, when evaluated with 3D strain imaging. In addition, preoperative 3D strain was demonstrated to be an independent predictor of acute and long-term clinical outcomes after cardiac surgery. The use of noninvasive 3D transthoracic echocardiogram strain imaging before cardiac surgery may provide added information to aid in perioperative risk stratification and management for these high-risk patients.

Speckle tracking strain imaging: Practical approach for application.

Speckle tracking strain imaging: Practical approach for application.

Exercise speckle-tracking strain imaging demonstrates impaired right ventricular contractile reserve in hypertrophic cardiomyopathy

AimsTo analyse right ventricular (RV) systolic function in patients with hypertrophic cardiomyopathy (HCM) at rest and during exercise, and its possible correlation with left ventricular(LV) morphology and function. Methods and resultsStandard echo, exercise stress echo, and RV 2D speckle-tracking strain (2DSE) were performed in 45 patients with HCM and in 45 age- and sex-comparable healthy controls. RV global longitudinal strain (GLS) was calculated by averaging local strains along the entire right ventricle. LV mass index and IVS wall thickness were significantly increased in HCM, while LV ejection fraction, RV diameters, RV tissue Doppler systolic peak and the RV end-systolic pressure-area relationship at rest were comparable between the two groups. Conversely, all transmitral Doppler indexes were significantly impaired in HCM. In addition, RV GLS and regional peak myocardial RV strains were significantly reduced in patients with HCM (all P<0.001). During physical effort, LV ejection fraction was comparable between the two groups. Conversely, LV E/Em ratio was significantly increased in HCM. Increase in TAPSE and RV tissue Doppler Sm peak velocity during effort were similar between the two groups. Conversely, increases of RV end-systolic pressure-area, regional and global RV strain were significantly lower in HCM patients (RV lateral strain: 10.3±3.5% of increase in HCM vs 20.5±4.5% in controls; p<0.0001). Multivariable analysis detected independent associations of RV lateral strain at peak stress with LV IVS thickness, maximal workload during exercise, and LV E/Em ratio during effort (all p<0.0001). An RV lateral 2DSE cut-off point of −14% differentiated controls and HCM with an 86%sensitivity and a 92% specificity. ConclusionsRV contractile reserve for HCM is impaired and this suggests that the lower resting values of RV in HCM may represent early subclinical myocardial damage, closely associated with exercise capacity.

Novel FBLN5 Mutation of Congenital Autosomal Recessive Cutis Laxa With Isolated Right Ventricular Non-Compaction (RVNC): New Findings on Echocardiographic Speckle-Tracking Strain Imaging of RVNC

: We report on a novel mutation in a two-year-old child with autosomal recessive cutis laxa with severe generalized laxity of the skin, prematurely aged appearance, conjunctival chalasia, episodes of severe rectal prolapse, isolated right ventricular non-compaction, (RVNC), significant pulmonary hypertension at the systemic arterial pressure level, severe tricuspid regurgitation, corpulmonale secondary to recurrent pulmonary infections, and mixed pulmonary fibrosis and emphysema. Next generation sequencing of cutis laxa genes identified a novel homozygous mutation in the FBLN5 gene (homozygous sequence alteration of c.907C > T [p. Gin303*] FBLN5 [ENS0342058]). Despite severe and generalized disorder in the patient’s connective tissues, she had no primary valvar or vascular abnormalities in the heart. Complete speckle-tracking strain imaging (SI) by two-dimensional echocardiography showed decreased systolic longitudinal and transverse strain in the involved segment of the right ventricle (RV).

Incremental Value of 2-Dimensional Longitudinal Radial and Circumferential Speckle Tracking Strain Imaging to Wall Motion Analysis for Detection of Coronary Artery Disease in Patients Undergoing Dobutamine Stress Echocardiography

Background: DSE is considered one of the good options in clinical practice but due to some limitations new promising modalities like speckle tracking echocardiography (STE) was introduced. STE is a new imaging technique that allows evaluation of global and regional myocardial function independently from the angle of acquisition and from cardiac translational movements. Objectives: Determine optimal cutoff values for longitudinal, radial and circumferential strains at peak DSE for detection of significant stenosis on CA. Also investigate incremental value of combining strain measurements to wall motion analysis. Methods: The study population comprised 100 patients (age 50 ±9 years) underwent high dose DSE, STE followed by CA. DSE and STE results were compared and added to each other and finally compared to CA result. Results: GLS cutoff points (-16.75%) showed significantly higher accuracy when compared to GCS and GRS, with highest balanced sensitivity and specificity to predict CAD. GLS, GRS and GCS reduced the DSE false positivity by 83%, 72.2% and 66.6% respectively. STE also showed better Agreement with CA than DSE in detecting coronary territorial affection especially LAD (Kappa= 0.775). Conclusions: STE is feasible during DSE, it helps increasing the diagnostic accuracy of DSE and decreasing its false positivity. Both global and segmental longitudinal strain can offer accurate, feasible and non invasive assessment of CAD.

Improvement in left ventricular deformational indices following radiofrequency ablation in patients with tachycardia: A comparative study between AVRT and AVNRT regarding left ventricular strain and strain rates

Background: Ablation will efficiently lead to sinus rhythm preservation, which consequently improves left ventricular function; however, the strain rate and its indices as functional systolic factors of the left ventricle have not been studied. Objectives: To assess the improvements in different patterns of radial, longitudinal, and circumferential strain rates separately. Methods: In this case series, 31 patients with symptomatic tachycardia who were candidates for ablation between october 2011 and March 2012 in our tertiary cardiovascular center in Iran were enrolled. Patients underwent trans-thoracic echocardiography 24 hours before and 24 hours and three months after ablation, and left ventricular ejection fraction deformation indices were assessed using the two-dimensional (2D) speckle tracking method during normal sinus rhythm. Results: Strain and strain rate indices in different aspects (radial and circumferential in the short axis view, and for longitudinal in the long axis view) improved remarkably during the three-month follow-up period (P< 0.05). The improvements in ventricular indices were usually between 24 hours to three months after ablation. The systolic strain rate (SR) and strain (SN) were significantly different at echocardiographic views before and 24 hours after ablation (P< 0.05), which revealed that myocardial function developed in the first 24 hours of ablation. Conclusions: Echocardiography and 2D speckle tracking strain imaging shows improvements in left ventricular deformation indices in atrioventricular reentrant tachycardia (AVRT) and atrioventricular nodal reentrant tachycardia (AVNRT) patients for the mean systolic strain and strain rate at 24 hours and the three-month follow-up. In spite of the normal LVEF, even during sinus rhythm, deformation indices maybe abnormal before and after ablation.

Determinants of New-Onset Atrial Fibrillation in Patients Receiving CRT: Mechanistic Insights From Speckle Tracking Imaging

ObjectivesThe aim of this study was to investigate the factors associated with the development of atrial fibrillation (AF) and to examine the impact of these factors for long-term outcome after cardiac resynchronization therapy (CRT). BackgroundThe effect of CRT on the development of new AF is under debate. MethodsClinical assessment, 12-lead electrocardiogram, echocardiography with speckle tracking strain imaging, and device interrogation before implantation and every 6 months thereafter were performed regularly over a 5-year follow-up. The primary endpoint was new-onset AF. Pre-specified outcome events were transplantation, assist device implantation, and death. ResultsDuring follow-up, AF occurred in 29 of 106 patients. Parameters of left atrial (LA) mechanics including mitral annular (A′) velocity, left atrial volume index (LAVI), LA ejection fraction, active emptying fraction, LA mean systolic strain (Ss) and late diastolic strain (Sa) improved at 6 months only in patients who remained free of AF. The change in LA Ss and Sa from baseline to 6 months after CRT had the highest accuracy to predict new-onset AF (area under the curve [AUC] = 0.793, 0.815, respectively, p < 0.0001 for both vs. left ventricular [LV] reverse remodeling AUC = 0.531; p < 0.01 for both). In addition, the change in LA Ss and Sa predicted outcome events independently from new-onset AF and LV volume response. ConclusionsLA functional improvement is essential for AF-free survival after CRT and is an independent predictor of AF-free survival. The improvement in LA Ss and Sa as a means of LA mechanical reserve also predicts long-term event-free survival after CRT independently from LV volume response and new-onset AF.

Clinical Application of Strain Imaging

Left ventricular (LV) dysfunction increases the risk for serious post-operative complications. Accurate assessment of LV wall motion is necessary to guide anesthetic management; however, traditional measures have a high degree of inter- and intra-observer variability. Myocardial deformation as measured by strain and strain rates is improving the diagnostic and prognostic utility of echocardiography to determine LV function in patients with cardiovascular disease. Strain can be measured using tissue Doppler and speckle tracking imaging from two-dimensional or three-dimensional echocardiography using various online and offline software packages. Tissue Doppler strain analysis provides excellent temporal resolution but is limited by the imaging angle of insonation. Speckle tracking strain imaging is angle independent and now the more commonly used modality. Strain has been demonstrated to guide therapy, monitor disease progression in various pathologic states, and is emerging as a strong predictor of clinical outcomes.