Evaluation of left ventricular short- and long-axis function in severe mitral regurgitation using 2-dimensional strain echocardiography

Timing of Surgery for Asymptomatic Primary Mitral Regurgitation: Possible Value of Early, Serial Measurements of Left Ventricular Sphericity

Asymptomatic primary mitral regurgitation due to myxomatous degeneration of the mitral valve leaflets may remain so for long periods, even as left ventricular function progresses to a decompensated stage. During the early compensated stage, the ventricle's initial response to the volume overload is an asymmetric increase in the diastolic short axis dimension, accomplished by a diastolic shift of the interventricular septum into the right ventricular cavity, creating a more spherical left ventricular diastolic shape, increasing diastolic filling and stroke volume. Early valve repair is recommended to reduce postoperative left ventricular dysfunction. Early serial measurements of left ventricular sphericity index [LV-Si]. during the compensated stage of mitral regurgitation might identify subtle changes in left ventricular shape and assist in determining the optimal earliest timing for surgical intervention.

Comparison of the 2005 Montreal Criteria and the 2019 Cirrhotic Cardiomyopathy Consortium Criteria for the Diagnosis of Cirrhotic Cardiomyopathy

The comparison between the diagnostic criteria for cirrhotic cardiomyopathy (CCM) first proposed in 2005 (2005 Montreal criteria), and those redefined in the 2019 Cirrhotic Cardiomyopathy Consortium (2019 CCC criteria) has generated significant controversy. Importantly, the predictive value of these criteria in cirrhotic patients (CPs) remains unclear to this date. Thus, the present study aims to compare the 2 sets of criteria and investigate their predictive value in CPs. Between April 2021 and April 2023, a total of 104 CPs with an average age of 46.4 ± 8.9 years, who had no history of other cardiac diseases or malignancies were enrolled in this prospective single-center observational cohort study, conducted at the Third Affiliated Hospital of Sun Yat-Sen University. Various echocardiographic indicators were measured and assessed for their prognostic value and association with clinical outcomes. The prevalence of CCM was found to be comparable when evaluated using both the 2019 CCC and 2005 Montreal criteria (54.8% vs 44.2%, p = 0.161). However, the diagnosis of systolic dysfunction was significantly different between the 2 criteria (52.9% vs 1.0%, p <0.001). Among patients with systolic dysfunction, 27.9% had reduced left ventricular global longitudinal strain, while 25% had increased left ventricular global longitudinal strain. Moreover, fewer patients were diagnosed with diastolic dysfunction (DD) using the 2019 CCC criteria (4.8% vs 44.2%, p <0.001). Multivariate Cox analysis revealed that CPs who had encephalopathy, a high model for end-stage liver disease score, and DD diagnosed using the 2019 CCC criteria exhibited a poorer prognosis. In conclusion, although the prevalence of CCM according to both criteria is similar, the consistency is poor, indicating that they are not the same group of patients. Importantly, CPs with DD diagnosed according to the 2019 CCC criteria might be associated with increased adverse events.

Prognostic impact of left ventricular global longitudinal strain in atrial mitral regurgitation

OBJECTIVE

Left atrial (LA) and left ventricular (LV) mechanics are impaired in patients with atrial functional mitral regurgitation (AFMR), but their prognostic value in this subset of patients remains unknown. The present study aimed to evaluate the association between LA and LV longitudinal strain and clinical outcomes in patients with AFMR.

METHODS

A total of 197 patients (mean age 73±10 years, 44% men) with at least moderate AFMR were retrospectively identified. LV global longitudinal strain (GLS) and left atrial reservoir strain (LAS) were calculated by two-dimensional speckle tracking echocardiography. All-cause mortality was the primary endpoint of the study. The threshold value of LV GLS (≤16.3%) to identify impaired LV mechanics was defined based on the risk excess of the primary endpoint described with a spline curve analysis.

RESULTS

Impaired LV GLS (≤16.3%) was found in 89 (45%) patients. During a median follow-up of 69 months, 45 (23%) subjects experienced the primary endpoint. Patients with impaired LV GLS (≤16.3%) had a significantly lower cumulative survival rate at 5 years, as compared with patients with LV GLS (>16.3%) (74% vs 93%, p<0.001). On multivariable Cox regression analysis, LV GLS expressed as continuous variable was independently associated with the occurrence of all-cause mortality (HR 0.856, 95% CI 0.763 to 0.960; p=0.008) after adjustment for age, LAS, pulmonary artery systolic pressure and severe tricuspid regurgitation. Conversely, LAS was not significantly associated with patients' outcome.

CONCLUSIONS

In patients with significant AFMR, the impairment of LV GLS was independently associated with worse outcomes.

Strain patterns in primary mitral regurgitation due to rheumatic heart disease and mitral valve prolapse

OBJECTIVE

Left atrial (LA) and left ventricular (LV) remodelling are the adaptive changes that occur in primary mitral regurgitation (MR) and are related to its clinical outcomes. Despite the pathophysiological differences in MR in rheumatic heart disease (RHD) and mitral valve prolapse (MVP), whether the pattern of LV and LA remodelling is different between the two conditions remains unknown. Hence, we compared the LA and LV strain pattern in MR due to RHD, the predominant etiology in developing countries topatients with MVP and age and sex-matched controls.

METHODS

A total of 50 patients of severe MR which included 30 MVP MR and 20 RHD MR were assessed by strain imaging by speckle tracking echocardiography (STE) and were compared with age and sex-matched controls. 2D STE was used for LA and 3D STE was used for LV strain analysis. LA and LV strain parameters were compared between MVP MR and RHD MR groups.

RESULTS

30 patients with MVP and 20 with RHD were studied. 60% (n = 30) were symptomatic. Mean GLS was -17.2 ± 4.4% compared to -20 ± 3.2% among controls and mean LA strain was 17.35 ± 10.3% compared to 51.34 ± 11.5% among controls which were significantly lower (both p < 0.01). No significant difference in LA strain and GLS was found between MVP and RHD subgroups (LA strain 20.45 ± 11.9% and 14.63 ± 8.85%; p = 0.08; GLS - 18.25 ± 4.3% and-16.2 ± 4.6%; p = 0.12). PALS in the RHD group was lower compared to MVP(p = 0.08) which showed a trend towards significance. LV strain parameters showed no significant difference among the MVP and RHD groups.

CONCLUSION

LA and LV strain parameters showed no significant difference in MR due to either RHD or MVP. There was a trend towards lower LA strain in RHD which needs validation with large multicentric studies. The current strain parameters from MVP with the prognostic value may be applied to MR of RHD etiology, pending confirmation of our results by other groups.

Predictors of left ventricular reverse remodeling after percutaneous therapy for mitral regurgitation with the MitraClip system

OBJECTIVES

To investigate the predictors and clinical impact of left ventricular reverse remodeling (LVRR) after MitraClip (MC) therapy for degenerative (DMR) and functional mitral regurgitation (FMR).

BACKGROUND

MC therapy induces LVRR in patients with mitral regurgitation (MR) at high-risk for surgery. However, specific data on predictors of LVRR therapy are limited.

METHODS

This study included 164 patients treated by MC implantation with complete clinical and echocardiographic evaluation at baseline, 6 months, and 12 months. LVRR was defined as a decrease of ≥10% of the left ventricular end-diastolic diameter after 12 months and was found in 49% of the patients.

RESULTS

LVRR was associated with significantly reduced event rate 2 years after MC procedure. In the total cohort, multivariate regression analysis determined severe recurrent/residual MR after 12 months (p = .010, odds ratio [OR] = 0.26), male gender (p = .050, OR = 0.49) and left ventricular ejection fraction (LVEF) <20% (p = .046, OR = 0.24) as predictors of absence of LVRR. In the subgroup analysis according to etiology of MR, multivariate regression analysis revealed severe recurrent/residual MR after 12 months (p = .04, OR = 0.184) to inversely predict LVRR only in the DMR subgroup. In FMR, residual severe tricuspid regurgitation (TR) inversely predicts LVRR (p = .032, OR = 0.361).

CONCLUSIONS

LVRR occurs in half of the patients after MC and is associated with reduced MACCE rates at follow-up. Combined information on residual/recurrent MR, baseline LVEF and gender predict LVRR after MC procedure. While residual/recurrent MR is the independent predictor for the absence of LVRR in DMR, in FMR only severe residual TR independently predict LVRR.

Global longitudinal strain is a hallmark of cardiac damage in mitral regurgitation: the Italian arm of the European Registry of mitral regurgitation (EuMiClip)

BACKGROUND

The search for reliable cardiac functional parameters is crucial in patients with mitral regurgitation (MR). In the Italian arm of the European Registry of MR, we compared the ability of global longitudinal strain (GLS) and left ventricular (LV) ejection fraction (LVEF) to detect cardiac damage in MR.

METHODS

Five hundred four consecutive patients with MR underwent a complete echo-Doppler exam. A total of 431, 53 and 20 patients had degenerative, secondary and mixed MR, respectively. The main echocardiographic parameters, including LV and left atrial (LA) size measurements, pulmonary artery systolic pressure (PASP) and GLS were compared between patients with mild MR (n = 392) vs. moderate to severe MR (n = 112).

RESULTS

LVEF and GLS were related one another in the pooled population, and separately in patients with mild and moderate/severe MR (all p < 0.0001). However, a certain number of patients were above the upper or below the lower limits of the 95% confidence interval (CI) of the normal relation in the pooled population and in patients with mild MR. Only 2 patients were below the 95% CI in moderate to severe MR. After adjusting for confounders by separate multivariate models, LVEF and GLS were independently associated with LV and left atrial size in the pooled population and in mild and moderate/severe MR. GLS, but not LVEF, was also independently associated with PASP in patients with mild and moderate to severe MR.

CONCLUSIONS

Both LVEF and GLS are independently associated with LV and LA size, but only GLS is related to pulmonary arterial pressure. GLS is a powerful hallmark of cardiac damage in MR.

Early Left and Right Ventricular Response to Aortic Valve Replacement

BACKGROUND

The immediate effect of aortic valve replacement (AVR) for aortic stenosis on perioperative myocardial function is unclear. Left ventricular (LV) function may be impaired by cardioplegia-induced myocardial arrest and ischemia-reperfusion injury, especially in patients with LV hypertrophy. Alternatively, LV function may improve when afterload is reduced after AVR. The right ventricle (RV), however, experiences cardioplegic arrest without benefiting from improved loading conditions. Which of these effects on myocardial function dominate in patients undergoing AVR for aortic stenosis has not been thoroughly explored. Our primary objective is thus to characterize the effect of intraoperative events on LV function during AVR using echocardiographic measures of myocardial deformation. Second, we evaluated RV function.

METHODS

In this supplementary analysis of 100 patients enrolled in a clinical trial (NCT01187329), 97 patients underwent AVR for aortic stenosis. Of these patients, 95 had a standardized intraoperative transesophageal echocardiographic examination of systolic and diastolic function performed before surgical incision and repeated after chest closure. Echocardiographic images were analyzed off-line for global longitudinal myocardial strain and strain rate using 2D speckle-tracking echocardiography. Myocardial deformation assessed at the beginning of surgery was compared with the end of surgery using paired t tests corrected for multiple comparisons.

RESULTS

LV volumes and arterial blood pressure decreased, and heart rate increased at the end of surgery. Echocardiographic images were acceptable for analysis in 72 patients for LV strain, 67 for LV strain rate, and 54 for RV strain and strain rate. In 72 patients with LV strain images, 9 patients required epinephrine, 22 required norepinephrine, and 2 required both at the end of surgery. LV strain did not change at the end of surgery compared with the beginning of surgery (difference: 0.7 [97.6% confidence interval, -0.2 to 1.5]%; P = 0.07), whereas LV systolic strain rate improved (became more negative) (-0.3 [-0.4 to -0.2] s; P < 0.001). In contrast, RV systolic strain worsened (became less negative) at the end of surgery (difference: 4.6 [3.1 to 6.0]%; P < 0.001) although RV systolic strain rate was unchanged (0.0 [97.6% confidence interval, -0.1 to 0.1]; P = 0.83).

CONCLUSIONS

LV function improved after replacement of a stenotic aortic valve demonstrated by improved longitudinal strain rate. In contrast, RV function, assessed by longitudinal strain, was reduced.

The modern role of transoesophageal echocardiography in the assessment of valvular pathologies

Despite significant advancements in the field of cardiovascular imaging, transoesophageal echocardiography remains the key imaging modality in the management of valvular pathologies. This paper provides echocardiographers with an overview of the modern role of TOE in the diagnosis and management of valvular disease. We describe how the introduction of 3D techniques has changed the detection and grading of valvular pathologies and concentrate on its role as a monitoring tool in interventional cardiology. In addition, we focus on the echocardiographic and Doppler techniques used in the assessment of prosthetic valves and provide guidance for the evaluation of prosthetic valves. Finally, we summarise quantitative methods used for the assessment of valvular stenosis and regurgitation and highlight the key areas where echocardiography remains superior over other novel imaging modalities.

Incremental Value of Two Dimensional Speckle Tracking Echocardiography in the Functional Assessment and Characterization of Subclinical Left Ventricular Dysfunction

Subclinical left ventricular (LV) dysfunction refers to subtle abnormalities in LV function which typically precede a reduction in the left ventricular ejection fraction (LVEF). The assessment of myocardial function using LVEF, a radial metric of systolic function, is subject to load dependence, intra-observer and inter-observer variability. Reductions in LVEF typically manifest late in the disease process thus compromising the ability to intervene before irreversible impairment of systolic performance sets in. 2-Dimensional speckle tracking echocardiography (2D-STE), a novel strain imaging modality has shown promise as a sensitive indicator of myocardial contractility. It arms the clinician with a powerful and practical tool to rapidly quantify cardiac mechanics, circumventing several inherent limitations of conventional echocardiography. This article highlights the incremental utility of 2D-STE in the detection of subclinical LV dysfunction.

Tissue Tracking Technology for Assessing Cardiac Mechanics: Principles, Normal Values, and Clinical Applications

Tissue tracking technologies such as speckle tracking echocardiography and feature tracking cardiac magnetic resonance have enhanced the noninvasive assessment of myocardial deformation in clinical research and clinical practice. The widespread enthusiasm for using tissue tracking techniques in research and clinical practice stems from the ready applicability of these technologies to routine echocardiographic or cardiac magnetic resonance images. The technology is common to both modalities, and derived parameters to describe myocardial mechanics are the similar, albeit with different accuracies. We provide an overview of the normal values and reproducibility of the clinically applicable parameters, together with their clinical validation. The use of these technologies in different clinical scenarios, and the additive value to current imaging diagnostics are discussed.

Predicting Left Ventricular Dysfunction after Surgery in Patients with Chronic Mitral Regurgitation: Assessment of Myocardial Deformation by 2-Dimensional Multilayer Speckle Tracking Echocardiography

Background and Objectives

The development of postoperative left ventricular (LV) dysfunction is a frequent complication in patients with chronic severe mitral valve regurgitation (MR) and portends a poor prognosis. Assessment of myocardial deformation enables myocardial contractility to be accurately estimated. The aim of the present study was to evaluate the predictive value of preoperative regional LV contractile function assessment using two-dimensional multilayer speckle-tracking echocardiography (2D MSTE) analysis in patients with chronic severe MR with preserved LV systolic function.

Subjects and Methods

Forty-three consecutive patients with chronic severe MR with preserved LV systolic function scheduled for mitral valve replacement (MVR) or MV repair were prospectively enrolled. Serial echocardiographic studies were performed before surgery, at 7 days follow-up, and at least 3 months follow-up postoperatively. The conventional echocardiographic parameters were analyzed. Global longitudinal strain (GLS) was obtained quantitatively by 2D MSTE.

Results

The mean age of patients was 51.7±14.3 years and 25 (58.1%) were male. In receiver-operating characteristic curve analysis, the most useful cutoff value for discriminating postoperative LV remodeling in severe MR with normal LV systolic function was -20.5% of 2D mid-layer GLS. Patients were divided into two groups by the baseline GLS -20.5%. Preoperative GLS values strongly predicted postoperative LV remodeling or LV dysfunction. The postoperative degree of decrease in LV end-diastolic dimension might be an additive predictive factor.

Conclusion

STE can be used to predict a decrease in LV function after MVR in patients with chronic severe MR. This promising method could be of use in the clinic when trying to decide upon the optimum time to schedule surgery for such patients.

Left ventricular systolic function assessment in secondary mitral regurgitation: left ventricular ejection fraction vs. speckle tracking global longitudinal strain

AIMS

Left ventricular (LV) ejection fraction (LVEF) is currently considered for the decision making of patients with mitral regurgitation (MR). However, LVEF represents change in LV volume between end-diastole and end-systole but does not characterize the intrinsic function of the myocardium. In contrast, speckle-tracking global longitudinal strain (GLS) characterizes myocardial deformation. The present study evaluated whether LV GLS may detect further impairment in LV systolic function in dilated cardiomyopathy patients with and without severe secondary MR matched based on LVEF.

METHODS AND RESULTS

Patients with non-ischaemic dilated cardiomyopathy (N = 150, 59 ± 12 years old, 58% male) were included: 75 patients with severe secondary MR and 75 patients with none or less than mild MR matched 1 : 1 according to LVEF. The LV systolic function was evaluated by LVEF (following Simpson's biplane method), forward ejection fraction (forward stroke volume relative to LV end-diastolic volume), and speckle-tracking GLS. By definition, LVEF was comparable between the two groups (patients with severe MR 31 ± 10 vs. patients with no/mild MR 31 ± 10%, P = 0.93). However, patients with severe MR had significantly lower forward ejection fraction (29 ± 14 vs. 40 ± 18%, P < 0.001) and more impaired GLS (-8.08 ± 3.33 vs. -9.78 ± 3.78%, P = 0.004) compared with their counterparts. The presence of severe secondary MR was significantly associated with worse LV GLS (β 1.32, 95% confidence interval 0.14-2.49, P = 0.03).

CONCLUSION

In patients with severe secondary MR, speckle-tracking GLS shows more deteriorated LV systolic function than LVEF.

Perioperative assessment of myocardial deformation

Evaluation of left ventricular performance improves risk assessment and guides anesthetic decisions. However, the most common echocardiographic measure of myocardial function, the left ventricular ejection fraction (LVEF), has important limitations. LVEF is limited by subjective interpretation that reduces accuracy and reproducibility, and LVEF assesses global function without characterizing regional myocardial abnormalities. An alternative objective echocardiographic measure of myocardial function is thus needed. Myocardial deformation analysis, which performs quantitative assessment of global and regional myocardial function, may be useful for perioperative care of surgical patients. Myocardial deformation analysis evaluates left ventricular mechanics by quantifying strain and strain rate. Strain describes percent change in myocardial length in the longitudinal (from base to apex) and circumferential (encircling the short-axis of the ventricle) direction and change in thickness in the radial direction. Segmental strain describes regional myocardial function. Strain is a negative number when the ventricle shortens longitudinally or circumferentially and is positive with radial thickening. Reference values for normal longitudinal strain from a recent meta-analysis by using transthoracic echocardiography are (mean ± SD) -19.7% ± 0.4%, while radial and circumferential strain are 47.3% ± 1.9% and -23.3% ± 0.7%, respectively. The speed of myocardial deformation is also important and is characterized by strain rate. Longitudinal systolic strain rate in healthy subjects averages -1.10 ± 0.16 s. Assessment of myocardial deformation requires consideration of both strain (change in deformation), which correlates with LVEF, and strain rate (speed of deformation), which correlates with rate of rise of left ventricular pressure (dP/dt). Myocardial deformation analysis also evaluates ventricular relaxation, twist, and untwist, providing new and noninvasive methods to assess components of myocardial systolic and diastolic function. Myocardial deformation analysis is based on either Doppler or a non-Doppler technique, called speckle-tracking echocardiography. Myocardial deformation analysis provides quantitative measures of global and regional myocardial function for use in the perioperative care of the surgical patient. For example, coronary graft occlusion after coronary artery bypass grafting is detected by an acute reduction in strain in the affected coronary artery territory. In addition, assessment of left ventricular mechanics detects underlying myocardial pathology before abnormalities become apparent on conventional echocardiography. Certainly, patients with aortic regurgitation demonstrate reduced longitudinal strain before reduction in LVEF occurs, which allows detection of subclinical left ventricular dysfunction and predicts increased risk for heart failure and impaired myocardial function after surgical repair. In this review, we describe the principles, techniques, and clinical application of myocardial deformation analysis.

Left ventricular twist and circumferential strain in dogs with myxomatous mitral valve disease

BACKGROUND

During the cardiac cycle, the ventricle undergoes a twisting motion because of the oblique orientation of the left ventricular (LV) myofibers. This can be quantified by speckle-tracking echocardiography (STE). In mitral regurgitation (MR) in humans, the short axis deformation has been suggested as being pivotal to LV function. Decreased and delayed LV twist has been described in experimental MR, but has not been studied in myxomatous mitral valve disease (MMVD).

HYPOTHESES

(1) Magnitude (CSt) and rate (CSRs) of systolic circumferential deformation decrease before the onset of congestive heart failure (CHF); (2) magnitude and rate of LV twist decrease, and onset of untwist is delayed, with increasing MMVD severity.

ANIMALS

A total of 97 privately owned small- to medium-sized dogs.

METHODS

Severity of MMVD was assessed by echocardiography and presence of clinical signs of CHF. Magnitude and rate of LV twist and circumferential deformation were evaluated by STE.

RESULTS

Dogs with CHF receiving treatment had increased CSt, CSRs, early diastolic untwisting rate, and delayed onset of untwist compared to dogs with minimal MMVD and increased systolic twist compared to dogs with mild MMVD (all P < .01). CSt and time to onset of untwist increased with echocardiographic variables of MR severity (all P < .002). CSRs and several LV twist variables decreased with increasing systolic LV internal diameter (all P < .01).

CONCLUSIONS AND CLINICAL IMPORTANCE

No STE-derived variable was decreased before onset of CHF. In dogs with CHF receiving treatment, the delayed onset of relaxation might indicate LV dysfunction and the hyperdynamic CSt and LV twist reflect compensatory mechanisms.

Left ventricular strain in chronic ischemic mitral regurgitation in relation to mitral tethering pattern

BACKGROUND

The aim of this retrospective study was to explore whether different tethering patterns in chronic ischemic mitral regurgitation have different distributions of left ventricular (LV) systolic longitudinal, circumferential, and radial strain before and after mitral valve repair.

METHODS

Sixty-one patients with chronic ischemic mitral regurgitation who underwent mitral repair were divided on the basis of the preoperative anterior/posterior tethering angle ratio (cutoff value, 0.76). There were 29 patients with symmetric (group 1) and 32 with asymmetric (group 2) preoperative tethering patterns. Assessment of longitudinal peak systolic strain was performed offline by applying speckle-tracking imaging to the apical two-chamber, three-chamber, and four-chamber views of the left ventricle. Peak systolic radial and circumferential strain was obtained from short-axis views at the basal, middle, and apical levels. Twenty healthy subjects served as controls.

RESULTS

In group 1, baseline LV strain was impaired in all LV segments, with the worst values in the anterolateral, anterior, and inferolateral segments at the midventricular and basal levels. In contrast, asymmetric patients showed higher values in the inferior and inferoseptal walls and values closer to normal in the other segments. After surgery, all strain measurements showed significant improvements in all LV segments in group 2, whereas in Group 1, strain worsened in the inferoseptal, inferior, and anteroseptal walls and did not change in the other segments.

CONCLUSIONS

Patients with baseline symmetric tethering patterns showed more extensive abnormal strain, which was observed in all LV segments and was not reverted by surgery. These findings require confirmation in additional larger studies.

Global and regional left ventricular myocardial deformation measures by magnetic resonance feature tracking in healthy volunteers: comparison with tagging and relevance of gender

BACKGROUND

Feature tracking software offers measurements of myocardial strain, velocities and displacement from cine cardiovascular magnetic resonance (CMR) images. We used it to record deformation parameters in healthy adults and compared values to those obtained by tagging.

METHODS

We used TomTec 2D Cardiac Performance Analysis software to derive global, regional and segmental myocardial deformation parameters in 145 healthy volunteers who had steady state free precession (SSFP) cine left ventricular short (basal, mid and apical levels) and long axis views (horizontal long axis, vertical long axis and left ventricular out flow tract) obtained on a 1.5 T Siemens Sonata scanner. 20 subjects also had tagged acquisitions and we compared global and regional deformation values obtained from these with those from Feature Tracking.

RESULTS

For globally averaged measurements of strain, only those measured circumferentially in short axis slices showed reasonably good levels of agreement between FT and tagging (limits of agreement -0.06 to 0.04). Longitudinal strain showed wide limits of agreement (-0.16 to 0.03) with evidence of overestimation of strain by FT relative to tagging as the mean of both measures increased. Radial strain was systematically overestimated by FT relative to tagging with very wide limits of agreement extending to as much as 100% of the mean value (-0.01 to 0.23). Reproducibility showed similar relative trends with acceptable global inter-observer variability for circumferential measures (coefficient of variation 4.9%) but poor reproducibility in the radial direction (coefficient of variation 32.3%). Ranges for deformation parameters varied between basal, mid and apical LV levels with higher levels at base compared to apex, and between genders by both FT and tagging.

CONCLUSIONS

FT measurements of circumferential but not longitudinally or radially directed global strain showed reasonable agreement with tagging and acceptable inter-observer reproducibility. We record provisional ranges of FT deformation parameters at global, regional and segmental levels. They show evidence of variation with gender and myocardial region in the volunteers studied, but have yet to be compared with tagging measurements at the segmental level.

Global and regional left ventricular myocardial deformation measures by magnetic resonance feature tracking in healthy volunteers: comparison with tagging and relevance of gender

BACKGROUND

Feature tracking software offers measurements of myocardial strain, velocities and displacement from cine cardiovascular magnetic resonance (CMR) images. We used it to record deformation parameters in healthy adults and compared values to those obtained by tagging.

METHODS

We used TomTec 2D Cardiac Performance Analysis software to derive global, regional and segmental myocardial deformation parameters in 145 healthy volunteers who had steady state free precession (SSFP) cine left ventricular short (basal, mid and apical levels) and long axis views (horizontal long axis, vertical long axis and left ventricular out flow tract) obtained on a 1.5 T Siemens Sonata scanner. 20 subjects also had tagged acquisitions and we compared global and regional deformation values obtained from these with those from Feature Tracking.

RESULTS

For globally averaged measurements of strain, only those measured circumferentially in short axis slices showed reasonably good levels of agreement between FT and tagging (limits of agreement -0.06 to 0.04). Longitudinal strain showed wide limits of agreement (-0.16 to 0.03) with evidence of overestimation of strain by FT relative to tagging as the mean of both measures increased. Radial strain was systematically overestimated by FT relative to tagging with very wide limits of agreement extending to as much as 100% of the mean value (-0.01 to 0.23). Reproducibility showed similar relative trends with acceptable global inter-observer variability for circumferential measures (coefficient of variation 4.9%) but poor reproducibility in the radial direction (coefficient of variation 32.3%). Ranges for deformation parameters varied between basal, mid and apical LV levels with higher levels at base compared to apex, and between genders by both FT and tagging.

CONCLUSIONS

FT measurements of circumferential but not longitudinally or radially directed global strain showed reasonable agreement with tagging and acceptable inter-observer reproducibility. We record provisional ranges of FT deformation parameters at global, regional and segmental levels. They show evidence of variation with gender and myocardial region in the volunteers studied, but have yet to be compared with tagging measurements at the segmental level.

Left ventricular dyssynchrony is associated with recurrence of ischemic mitral regurgitation after restrictive annuloplasty

BACKGROUND

In our study, we investigated the impact of papillary muscle systolic dyssynchrony (DYS-PAP) obtained by 2D speckle-tracking echocardiography (2D-STE) in the prediction of recurrent ischemic mitral regurgitation (MR) after restrictive annuloplasty.

METHODS

The study population consisted of 524 consecutive patients who survived coronary artery bypass grafting (CABG) and restrictive annuloplasty, performed between 2001 and 2010 at 3 different Institutions and who met inclusion criteria. The assessment of DYS-PAP was performed preoperatively and at follow-up (median 45.3 months [IQR 26-67]) by 2D-STE in the apical four-chamber view for the anterolateral papillary muscle (ALPM) and apical long-axis view for the posteromedial papillary muscle (PMPM).

RESULTS

Recurrence of MR (≥ 2+ in patients with no/trivial MR at discharge) was found in 112 patients (21.3%) at follow-up. Compared to patients without recurrence of MR, these patients had higher DYS-PAP values at baseline (60.6 ± 4.4 ms vs. 47.2 ± 2.9 ms, p<0.001) which significantly worsened at follow-up (74.4 ± 5.2 ms, p=0.002 vs. baseline). In contrast, in patients with no MR recurrence, DYS-PAP was significantly reduced (25.3 ± 4.4 ms, p=0.002 vs. baseline). At logistic regression analysis DYS-PAP (odds ratio [OR]: 4.8, 95% Confidence Interval [CI]: 3.4-8.2, p<0.001), was the strongest predictor of recurrent MR with a cutoff ≥ 58 ms (95%CI 51-66 ms). The model showed an area under the Receiver Operating Characteristic (ROC) curve of 0.97 (CI 0.94-0.99 [optimism-corrected 0.94; CI 0.89-0.95]) with 98% sensitivity (CI 96-100% [optimism-corrected 95%; CI 91-96%]) and 90% specificity (CI 85-94% [optimism-corrected 87%; CI 82-90%]).

CONCLUSIONS

DYS-PAP represents a reliable tool to identify patients with ischemic MR who can benefit from restrictive annuloplasty.

Left ventricular mechanics following restrictive mitral annuloplasty for functional mitral regurgitation: two-dimensional speckle tracking echocardiographic study

BACKGROUND

Restrictive mitral annuloplasty (RMA) is widely employed for patients with functional mitral regurgitation (MR). Its improvement of left ventricular (LV) function has been demonstrated by only a gradual increase in LV ejection fraction (EF) in the chronic phase. However, the detailed evaluation of changes in LV function has not been fully elucidated in functional MR patients before and after RMA. Therefore, we performed two-dimensional speckle tracking echocardiography (2D-STE), which enables accurate evaluation of myocardial deformation and rotation that are undetectable by conventional echocardiography.

METHODS

We studied 13 patients (mean age 61 ± 10 years) with functional MR associated with cardiomyopathy undergoing RMA. In addition to conventional echocardiographic measurements, 2D-STE was performed to measure peak systolic radial (RS), circumferential (CS), and longitudinal (LS) strains and twist before and 4 ± 2 weeks after surgery. LV twist was defined as the difference between the apical and basal rotations.

RESULTS

After RMA, EF and LS remained unchanged, but RS and CS were significantly improved at the mid-LV (RS, 20.6 ± 10.8 vs 24.5 ± 11.6%; CS, -9.6 ± 5.2 vs -12.8 ± 5.6%) and at the apex (RS, 15.0 ± 12.2 vs 18.7 ± 8.6%; CS, -4.4 ± 3.0 vs -7.8 ± 4.8%). RS and CS were unchanged at the base. The apical and basal rotations changed significantly, from 3.5°± 0.7° to 9.2°± 2.1°, and -2.1°± 0.7° to -3.8°± 1.0°, respectively. Consequently, the LV twist increased significantly, from 5.6°± 1.0° to 13.0°± 1.9°.

CONCLUSIONS

Radial and circumferential strains and LV twist increased significantly in the early postoperative period in functional MR patients after RMA and concomitant procedures.

Two-dimensional speckle tracking for quantification of left ventricular circumferential and radial wall motion in horses

REASONS FOR PERFORMING STUDY

The use of two-dimensional speckle tracking (2DST) for quantification of left ventricular (LV) function has recently been described in horses using long-axis images and short-axis images at chordal but not at papillary muscle level.

OBJECTIVES

To compare the feasibility and reliability of 2DST for quantification of circumferential and radial LV function in short-axis images at papillary muscle and chordal level.

METHODS

Repeated echocardiographic examinations were performed on 10 healthy trotter horses by 2 observers from a right parasternal short-axis view at papillary muscle and chordal level. Segmental and averaged peak values and timing of circumferential and radial strain and strain rate, radial displacement and rotation were measured in 6 LV wall segments in each imaging plane. Global peak values were calculated for circumferential strain and strain rate. The inter- and intraobserver within- and between-day variability was assessed by calculating coefficients of variation for repeated measurements.

RESULTS

2DST analysis was feasible in each cardiac cycle, although tracking was often inadequate during early diastole. Measurements of averaged systolic circumferential and radial strain and strain rate and radial displacement as well as global circumferential strain and strain rate could be determined with low variability. Early and late diastolic strain rate and systolic rotation showed a moderate variability. Radial segmental measurements were more reliable than circumferential measurements. The interventricular septum showed a higher circumferential and lower radial strain compared with the LV free wall. Peak timing was earlier at papillary muscle compared with chordal level.

CONCLUSIONS

2DST measurements of global and regional circumferential and radial LV wall motion are feasible both at papillary muscle and chordal level.

POTENTIAL RELEVANCE

Several measurements had good reliability and should be used for evaluation of the technique in a clinical setting.

Assessment of myocardial mechanics using speckle tracking echocardiography: fundamentals and clinical applications

The authors summarize the recent developments in speckle-tracking echocardiography (STE), a relatively new technique that can be used in conjunction with two-dimensional or three-dimensional echocardiography for resolving the multidirectional components of left ventricular (LV) deformation. The tracking system is based on grayscale B-mode images and is obtained by automatic measurement of the distance between 2 pixels of an LV segment during the cardiac cycle, independent of the angle of insonation. The integration of STE with real-time cardiac ultrasound imaging overcomes some of the limitations of previous work in the field and has the potential to provide a unified framework to more accurately quantify the regional and global function of the left ventricle. STE holds promise to reduce interobserver and intraobserver variability in assessing regional LV function and to improve patient care while reducing health care costs through the early identification of subclinical disease. Following a brief overview of the approach, the authors pool the initial observations from clinical studies on the development, validation, merits, and limitations of STE.

High-frequency high-resolution echocardiography: first evidence on non-invasive repeated measure of myocardial strain, contractility, and mitral regurgitation in the ischemia-reperfused murine heart

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized. The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed.

Impact of Longitudinal Cardiac Rotation on Mitral and Tricuspid Atrioventricular Annular Diastolic Motion

Background—

It is unknown whether longitudinal rotation (LR), often seen in cardiac resynchronization therapy candidates, may affect mitral annular early diastolic (E′) velocities and tricuspid annular motion. We assessed whether (1) LR affects the amplitude and timing of septal and lateral mitral annular E′ velocities and tricuspid annular systolic and E′ velocities and (2) if systolic strain heterogeneity seen in cardiac resynchronization therapy patients with LR extends into diastole.

Methods and Results—

Ninety-nine cardiac resynchronization therapy candidates with suitable baseline echocardiograms were identified. Early diastolic (E′) and systolic myocardial velocities of the tricuspid annulus and E′ velocities of the septal and lateral part of the mitral annulus were analyzed from tissue Doppler images. Longitudinal rotation and basal systolic and diastolic strain rates were analyzed by speckle-tracking. LR correlated with lateral mitral annular E′ ( r =0.45, P <0.001), tricuspid annular E′ ( r =−0.3, P =0.003), and with a difference between septal and lateral mitral annular E′ velocities ( r =−0.49, P <0.001) but not with septal mitral annular E′ velocity. LR also correlated with tricuspid annular systolic velocity ( r =0.60, P <0.001). After categorizing the patients according to the quartiles of their LR, we showed that with decreasing quartile number, heterogeneity of systolic ( P =0.003) but not diastolic ( P >0.1) strain rates increased.

Conclusions—

LR direction and magnitude correlates with the amplitude of, and relative differences between, diastolic velocities of tricuspid, lateral mitral, and septal mitral annulus, which are a cornerstone of diastolic function assessment. LR is associated with systolic but not with diastolic regional heterogeneity.