Left ventricle longitudinal deformation assessment by mitral annulus displacement or global longitudinal strain in chronic ischemic heart disease: are they interchangeable?

Considering Both GLS and MD for a Prognostic Value in Non-ST-Segment Elevated Acute Coronary Artery Syndrome

Global longitudinal strain (GLS) and mechanical dispersion (MD), as determined by 2D speckle tracking echocardiography, have been demonstrated to be reliable indicators of prognosis in a variety of cardiovascular illnesses. There are not many papers that discuss the prognostic significance of GLS and MD in a population with non-ST-segment elevated acute coronary syndrome (NSTE-ACS). Our study objective was to examine the predictive utility of the novel GLS/MD two-dimensional strain index in NSTE-ACS patients. Before discharge and four to six weeks later, echocardiography was performed on 310 consecutive hospitalized patients with NSTE-ACS and effective percutaneous coronary intervention (PCI). Cardiac mortality, malignant ventricular arrhythmia, or readmission owing to heart failure or reinfarction were the major end points. A total of 109 patients (35.16%) experienced cardiac incidents during the follow-up period (34.7 ± 8 months). The GLS/MD index at discharge was determined to be the greatest independent predictor of composite result by receiver operating characteristic analysis. The ideal cut-off value was -0.229. GLS/MD was determined to be the top independent predictor of cardiac events by multivariate Cox regression analysis. Patients with an initial GLS/MD > -0.229 that deteriorated after four to six weeks had the worst prognosis for a composite outcome, readmission, and cardiac death according to a Kaplan-Meier analysis (all p < 0.001). In conclusion, the GLS/MD ratio is a strong indicator of clinical fate in NSTE-ACS patients, especially if it is accompanied by deterioration.

Feasibility study of automated cardiac motion quantification to assess left ventricular function in type 2 diabetes

The global incidence of diabetes and related complications is gradually increasing, with cardiovascular complications being the leading cause of death in the diabetic population. The purpose of this study was to examine left ventricular function in individuals with type 2 diabetes mellitus (T2D) and conduct a feasibility analysis using automated cardiac motion quantification (aCMQ) approach. A total of 150 T2D patients with a history of diabetes mellitus dating back more than 10 years were chosen, and we treated 87 patients with T2D that had been present for less than 15 years as group I, 63 patients with T2D that had been present for more than 15 years as group II, and 50 healthy volunteers as the control group. From the three groups, clinical information, conventional ultrasonography parameters, and mitral annular plane systolic excursion (MAPSE) parameters were gathered. aCMQ technique was used to collect longitudinal strain and circumferential strain in the left ventricle. Tissue motion mitral annular displacement technique (TMAD) in aCMQ was used to collect parameters related to TMAD, and cardiac motion quantification (CMQ) was used to collect two-dimensional global longitudinal strain (2D-GLS) to compare the degree of difference between the aforementioned three groups. The differences between longitudinal strain groups in aCMQ were all statistically significant and gradually decreased with increasing disease duration. Most TMAD parameters were lower in groups I and II than in the control group, and TMAD parameters gradually decreased with increasing disease duration. The results of the LV global longitudinal strain and 2D-GLS using Bland-Altman analyses showed high agreement between and within groups, Pearson correlation analysis showed a significant positive correlation (r = 0.18, P < 0.05), and the AUC of ROC curves predicting the value of left ventricular function in patients with T2D was 0.723 and 0.628, respectively. With significant positive correlations between MAPSE, s', and the majority of the TAMD parameters (P < 0.05), TAMD, MAPSE, and s' demonstrated high inter- and intra-group agreement using Bland-Altman analyses, and the three had predictive value in assessing left ventricular function in T2D patients by ROC curve. Reduced longitudinal strain and reduced mitral annular displacement were seen in patients with different disease stages of T2D, so the application of aCMQ and TAMD was effective in detecting altered left ventricular function in patients with T2D. aCMQ had higher value in predicting left ventricular function in patients with T2D compared to CMQ for overall longitudinal strain, and the software performed the depiction automatically, reducing manual errors. MAPSE parameters and s ' can replace the TMAD technique for assessing mitral annular motion and was simpler to perform, saving operational time.

Feasibility of tissue-tracking mitral annular displacement in single four-chamber view as a simple index of left ventricular longitudinal deformation

BACKGROUND

Left ventricular global longitudinal strain (LVGLS) has prognostic value for adverse cardiac events. Application of speckle-tracking technology to mitral annulus provides easy assessment of tissue-tracking mitral annular displacement (TMAD) in apical four-chamber view. The study aimed to examine whether TMAD can be used as a simple index of LV longitudinal deformation in patients with and without preserved ejection fraction (EF).

METHODS

The study population consisted of 95 consecutive subjects. GLS was assessed from three apical views. TMAD was evaluated as the base-to-apex displacement of septal (TMADsep), lateral (TMADlat), and mid-point of annular line (TMADmid) in apical 4-chamber view. The percentage of TMADmid to LV length from the mid-point of mitral annuls to the apex at end-diastole (%TMADmid) was calculated. We compared each TMAD parameter with GLS by linear regression analysis, and analyzed each TMAD parameter by receiver operating characteristic (ROC) curve to detect impaired LV longitudinal deformation (|GLS|< 15.0%).

RESULTS

There were good correlations between each TMAD parameter and GLS (TMADsep: r² = 0.59, p < 0.01. TMADlat: r² = 0.65, p < 0.01. TMADmid: r² = 0.68, p < 0.01. %TMADmid: r² = 0.75, p < 0.01). According to ROC curve, %TMADmid < 10.5% was the best cut-off value in determining impaired LV longitudinal deformation (|GLS|≤ 15.0%) with a sensitivity of 95% and a specificity of 93%. The area under the curve (AUC) of %TMADmid was 0.98 (95% confidence intervals (CI) 0.93-0.99).

CONCLUSIONS

TMAD using speckle-tracking echocardiography quickly estimated from single apical four-chamber view can be used as a simple index for detection of impaired LV longitudinal deformation in patients with and without preserved EF.

Variable definitions and treatment approaches for atrial functional mitral regurgitation: A scoping review of the literature

OBJECTIVES

Atrial functional mitral regurgitation (AFMR) is a subtype of functional mitral regurgitation due to longstanding atrial fibrillation (AF) or heart failure with preserved ejection fraction. The variation in AFMR' definition and the common mode of treatment described in the literature remain unknown.

METHODS

We performed a scoping review of studies that surgically treated AFMR to characterize the existing variability in the definition of AFMR, the type of operations performed for AFMR valvulopathy, and the treatment for the chronic AF. We searched Medline, EMBASE, Cochrane Library, Scopus, and Web of Science since their inceptions for studies of patients affected by AFMR and surgically treated for their valvulopathy.

RESULTS

Twelve studies (n = 494 patients) met eligibility criteria. All studies excluded patients with signs of left ventricular (LV) dysfunction, but the way additional parameters were used to define AFMR at a more granular level varied across studies: nine studies (75%) used the presence of AF to define their AFMR cohorts, with five (41.2%) requiring a history of AF of >1 year; additionally, the threshold values for the LV ejection fraction differed (45%-55%). Isolated mitral annuloplasty was performed in 96.2% of patients. Broad variability was detected in the proportion of patients undergoing the Cox-Maze procedure (range, 17.8%-79.5%), pulmonary vein isolation (0.0%-66.7%), and left atrial appendage ligation (0.0%-100.0%).

CONCLUSIONS

AFMR remains variably defined in surgical studies, making comparisons across studies difficult. Mitral annuloplasty was most commonly performed. The proportion of AFMR patients undergoing concomitant procedures for AF varied substantially.

Tissue Mitral Annular Displacement in Patients With Myocardial Infarction - Comparison With Global Longitudinal Strain

Background: Global longitudinal strain (GLS) can predict prognosis after myocardial infarction (MI). Tissue mitral annular displacement (TMAD) is another index of longitudinal left ventricular deformity, and is less dependent on image quality than GLS. We investigated the relationship between TMAD and GLS, and their ability to predict outcomes after MI. Methods and Results: GLS and TMAD were measured on echocardiograms 2 weeks after MI in 246 consecutive patients (median age 62 years, 85.7% male). TMAD was measured from apical 4- and 2-chamber views (TMAD4ch and TMAD2ch, respectively), and a mean value (TMADav) was calculated. TMAD4ch, TMAD2ch, and GLS were successfully measured in 240 (97.5%), 210 (85.3%) and 214 patients (87.0%), respectively. All TMAD parameters were significantly correlated with GLS (R=0.71-0.75) and left ventricular ejection fraction (LVEF; R=0.48-0.53). TMAD parameters were weakly correlated with peak creatine kinase (CK; R=0.20) and CK-MB (R=0.21-0.25). GLS and TMADav were significantly associated with LVEF after 6 months (R=0.48-0.53) and all-cause mortality during the follow-up period (median 1,242 days). TMADav discriminated patients with higher all-cause mortality when patients were divided into 3 groups, namely upper 25%, middle range, and lower 25% of TMADav (P=0.041, log-rank test). GLS detected high-risk patients using 15.0% as a cut-off value. Conclusions: TMAD could be a simple and reliable alternative to GLS for predicting outcomes in patients with MI.

Validation of estimating left ventricular ejection fraction by mitral annular displacement derived from speckle-tracking echocardiography: A neglected method for evaluating left ventricular systolic function

PURPOSE

The echocardiographic measurement of left ventricular (LV) ejection fraction (EF) is dependent on professional experience and adequate visualization. Tissue motion of mitral annular displacement (TMAD) can be easily assessed using speckle-tracking echocardiography (STE), even in patients with poor acoustic windows. Therefore, this study aimed to assess whether left ventricular ejection fraction (LVEF) can be estimated using STE-derived TMAD when LVEF is not available.

METHODS

Four-hundred fifty-six outpatients were enrolled after excluding the patients whose LVEF measurements remained challenging or TMAD value could be confounded. An optimized regression model for LVEF-TMAD was developed in the derivation set (n = 287), and its reliability was verified in the validation set (n = 123) and regional wall motion abnormalities (RWMA) set (n = 46).

RESULTS

In the derivation set, the power models had the highest F-value. Therefore, the power equations were chosen to estimate LVEF by TMAD in the validation set. There was a near-zero bias and a narrow range between the observed and estimated LVEF. The highest intra-class correlation coefficient was found between the observed and the estimated LVEF by normalized TMAD at the midpoint of mitral annular (nTMADmid). Moreover, there were no significant differences between the observed and the estimated LVEF in the RWMA set.

CONCLUSION

The LVEF can be estimated with STE-derived TMAD, even for patients with RWMA, and nTMADmid may be the optimal parameter.

Detection of congestive heart failure by mitral annular displacement in cats with hypertrophic cardiomyopathy - concordance between tissue Doppler imaging-derived tissue tracking and M-mode

INTRODUCTION

The left ventricular systolic longitudinal function, traditionally measured by M-mode-derived mitral annular plane systolic excursion (MAPSE), is reduced in feline hypertrophic cardiomyopathy (HCM) and further reduced in cats with left-sided congestive heart failure (CHF). The objectives of this study were to compare longitudinal displacement measured by tissue tracking (TT-LD) and MAPSE in feline HCM and assess these methods' ability to differentiate CHF from preclinical HCM. A further objective was to provide preliminary reference intervals for TT-LD.

ANIMALS

Eighty-five client-owned cats.

METHODS

A retrospective case-control study. Anatomical M-mode was used to record MAPSE, and TT-LD was recorded by tissue tracking.

RESULTS

Reduced longitudinal displacement measured by either MAPSE or TT-LD was significantly associated with CHF in cats with HCM (p < 0.036). Receiver-operating characteristic analysis indicated that TT-LD (AUC: 92.9%-97.9%) was more sensitive and specific than MAPSE (AUC: 85.8%-89.1%) for the detection of CHF. A diagnostic cut-off of 2.89 mm for maximal TT-LD in the left ventricular septum resulted in a sensitivity and specificity of 100% and 83.3%, while a diagnostic cut-off of 2.41 mm in the left ventricular posterior wall resulted in a sensitivity of 100% and a specificity of 90%.

CONCLUSIONS

M-mode-derived mitral annular plane systolic excursion and TT-LD were strongly correlated, but not interchangeable. Longitudinal displacement measured by tissue tracking decreased more with disease severity than traditional MAPSE. Longitudinal displacement may help detect CHF in cats with HCM - with the maximal TT-LD of the left ventricular posterior wall achieving the highest AUC value.

Prognostic value of left ventricular mitral annular longitudinal displacement obtained by tissue Doppler imaging in patients with heart failure with reduced ejection fraction

Background

Tissue Doppler imaging (TDI) can be used to measure the mitral annular longitudinal displacement (LD) during systole. However, the prognostic utility of global and regional LD in patients with heart failure with reduced ejection fraction (HFrEF) is unknown.

Methods

Echocardiographic examinations from 907 patients with HFrEF were analysed obtaining conventional echocardiographic measurements. Regional LD was obtained from colour TDI projections in six mitral annular regions and global LD was calculated as an average.

Results

Mean age was 67 years, 26.9% were women and mean left ventricular ejection fraction was 27%. During a median follow-up period of 40 months, 150 (16.5 %) patients died. The risk of dying increased with decreasing tertile of global LD and was approximately five times higher for patients in the lowest tertile compared with the highest (1. tertile vs 3. tertile, HR 4.9, 95% CI: 3.0 to 7.9, p<0.001).

Global LD was a significant independent predictor of mortality after adjusting for age, gender, body mass index, pacemaker, heart rate, atrial fibrillation, diabetes and conventional echocardiographic measures and global longitudinal strain: HR 1.16 (95% CI: 1.00 to 1.34, p=0.044) per 1 mm decrease.

For regional measures, inferior LD was also a significant independent predictor in the multivariable model: HR 1.16 (95% CI: 1.04 to 1.29, p=0.006) and adding inferior LD to the conventional measures yielded a significant increase in Harrell’s C-statistic (95% CI: 0.75 to 0.78, p=0.009).

Conclusion

In patients with HFrEF, global and inferior LD are independent predictors of all-cause mortality. Furthermore, inferior LD proved to be a significant prognosticator when compared with all the conventional echocardiographic parameters.

Comparison of mitral annular displacement and global longitudinal strain imaging for predicting significant coronary atherosclerotic disease in patients of chronic stable angina pectoris

Myocardial strain by two-dimensional speckle-tracking echocardiography (2D-STE) is a validated clinical index of myocardial deformation, for predicting CAD in patients with chronic stable angina pectoris (CSAP) with preserved ejection fraction (EF). However, it is complex, imaging dependant with intra and intervendor variability. The mitral annulus displacement (MAD) has been correlated to left ventricular (LV) longitudinal deformation and may be interchanged with strain imaging. This cross-sectional study was conducted on patients with suspected CSAP (n = 146) and preserved LVEF without wall motion abnormalities. We excluded patients with prior heart disease, ACS, arrhythmia, heart failure or poor imaging. GLS, Average MAD and normalized MAD were calculated using 2D-STE by automated function imaging. CAG was gold standard. MAD had significantly lesser dropout due to suboptimal imaging. Receiver operating characteristic (ROC) analysis showed that GLS had significantly better area under curve (AUC) compared to Normalised MAD and Average MAD (P = 0.035) in predicting significant CAD in patients of CSAP. The optimal cut-off of GLS, normalized MAD and Average MAD were ≥  - 20.67% (sensitivity 94.2%, specificity 86.7%), ≤ 15.22% (sensitivity 90.7%, specificity 80%) and ≤ 11.18 mm (sensitivity 83.7%, specificity 71.1%) respectively. GLS showed strong correlation with Normalised MAD (R = 0.669, P < 0.001) and good correlation to Average MAD (R 0.572, P < 0.001). Absolute GLS and Normalised MAD showed significant inverse correlation to SYNTAX score. GLS is a more accurate measure for predicting presence and severity of CAD then MAD however latter is a reliable simpler, robust, and expeditious tool with lesser dropouts. It can be at least of complementary value to other imaging markers for myocardial function when LV curvatures are poorly visualized or in busy outdoors with time constraint.

Monitoring Canine Myocardial Infarction Formation and Recovery via Transthoracic Cardiac Strain Imaging

Myocardial elastography (ME) is an ultrasound-based strain imaging method that aims to determine the degree of ischemia or infarction as a result of the change in the elastic properties of the myocardium. A survival canine model (n = 11) was employed to investigate the ability of ME to image myocardial infarction formation and recovery. Infarcts were generated by ligation of the left anterior descending coronary artery. Canines were survived and imaged for 4 days (n = 7) or 4 weeks (n = 4), allowing sufficient time for recovery via collateral perfusion. A radial strain-based metric, percentage of healthy myocardium by strain (PHMε), was developed as a marker for healthy myocardial tissue. PHMε was strongly linearly correlated with actual infarct size as determined by gross pathology (R2 = 0.80). Mean PHMε was reduced 1-3 days post-infarction (p < 0.05) at the papillary and apical short-axis levels; full infarct recovery was achieved by day 28, with mean PHMε returning to baseline levels. ME was capable of diagnosing individual myocardial segments as non-infarcted or infarcted with high sensitivity (82%), specificity (92%) and precision (85%) (area under the receiver operating characteristic curve = 0.90). The study therefore strengthens the ME premise that it can detect and assess myocardial infarction progression and recovery in vivo and could thus provide an important role in both disease diagnosis and treatment assesssment.

Towards standardization of echocardiography for the evaluation of left ventricular function in adult rodents: a position paper of the ESC Working Group on Myocardial Function

Echocardiography is a reliable and reproducible method to assess non-invasively cardiac function in clinical and experimental research. Significant progress in the development of echocardiographic equipment and transducers has led to the successful translation of this methodology from humans to rodents, allowing for the scoring of disease severity and progression, testing of new drugs, and monitoring cardiac function in genetically modified or pharmacologically treated animals. However, as yet, there is no standardization in the procedure to acquire echocardiographic measurements in small animals. This position paper focuses on the appropriate acquisition and analysis of echocardiographic parameters in adult mice and rats, and provides reference values, representative images, and videos for the accurate and reproducible quantification of left ventricular function in healthy and pathological conditions.

Agreement between anatomical M-mode and tissue Doppler imaging in the assessment of fetal atrioventricular annular plane displacement in uncomplicated pregnancies: A prospective longitudinal study

AIM

To evaluate the level of agreement between M-mode and pulsed-wave tissue Doppler imaging (PW-TDI) techniques in assessing fetal mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE) and septal annular plane systolic excursion (SAPSE) in a low-risk population.

METHODS

This prospective longitudinal study included healthy fetuses assessed from 18 to 40 weeks of gestation. Tricuspid annular plane systolic excursion, MAPSE and SAPSE were measured using anatomical M-mode and PW-TDI. The agreement between the two diagnostic tests was assessed using Bland-Altman analysis.

RESULTS

Fifty fetuses were included in the final analysis. Mean values of TASPE were higher than that of MAPSE. There was a progressive increase of TAPSE, MAPSE and SAPSE values with advancing gestation. For each parameter assessed, there was an overall good agreement between the measurements obtained with M-mode and PW-TDI techniques. However, the measurements made with M-mode were slightly higher than those obtained with PW-TDI (mean differences: 0.03, 0.05 and 0.03 cm for TAPSE, MAPSE and SAPSE, respectively). When stratifying the analyses by gestational age, the mean values of TAPSE, MAPSE and SAPSE measured with M-Mode were higher compared to those obtained with PW-TDI, although the mean differences between the two techniques tended to narrow with increasing gestation. Tricuspid annular plane systolic excursion, MAPSE and SAPSE measurements were all significantly, positively associated with gestational age (all P < 0.001).

CONCLUSION

Fetal atrioventricular annular plane displacement can be assessed with M-mode technique, or with PW-TDI as the velocity-time integral of the myocardial systolic waveform. Atrioventricular annular plane displacement values obtained with M-mode technique are slightly higher than those obtained with PW-TDI.

Effect on Cardiac Function of Longstanding Juvenile-onset Mixed Connective Tissue Disease: A Controlled Study

OBJECTIVE

To assess cardiac function in patients with juvenile mixed connective tissue disease (JMCTD) compared to matched controls, and to investigate possible associations between cardiac impairment and disease variables and cardiovascular risk factors.

METHODS

Fifty JMCTD patients (86% female) examined median 14.9 (6.6-23.0) years after disease onset were compared with 50 age- and sex-matched controls. Electrocardiogram and echocardiography [including e' as a marker for diastolic dysfunction and long-axis strain (LAS) and left ventricular (LV) ejection fraction (EF) as markers of systolic function] were performed. LV dysfunction (LVD) was defined as low EF, low LAS, or low e'. Right ventricular function was assessed with tricuspid annular plane systolic excursion (TAPSE). Cardiovascular risk factors and disease variables were assessed.

RESULTS

LVD was found in 16% of patients and 4% of controls (p = 0.035). EF and LAS were lower in patients compared to controls (6% lower, p < 0.001, and 4% lower, p = 0.044, respectively). TAPSE was 8% lower in patients versus controls (p = 0.008). No patients had signs of pulmonary hypertension. Patients had longer corrected QT time than controls (p = 0.012). LVD was associated with higher levels of apolipoprotein B, higher disease activity measured by physician's global assessment, longer prednisolone treatment, and more organ damage assessed with the Myositis Damage Index.

CONCLUSION

Patients with JMCTD had impaired left and right ventricular function compared to matched controls after median 15 years disease duration. High disease activity and longer treatment with prednisolone were factors associated with LVD.

Ventricular force-frequency relationships during biventricular or multisite pacing in congenital heart disease

BACKGROUND

Traditional indices to evaluate biventricular (BiV) pacing are load dependent, fail to assess dynamic changes, and may not be appropriate in patients with congenital heart disease (CHD). We therefore measured the force-frequency relationship (FFR) using tissue Doppler-derived isovolumic acceleration (IVA) to assess the dynamic adaption of the myocardium and its variability with different ventricular pacing strategies.

METHODS

This was a prospective pilot study of pediatric and young adult CHD patients with biventricular or multisite pacing systems. Color-coded myocardial velocities were recorded at the base of the systemic ventricular free wall. IVA was calculated at resting heart rate and with incremental pacing. FFR curves were obtained by plotting IVA against heart rate for different ventricular pacing strategies.

RESULTS

Ten patients were included (mean: 22 ± 7 years). The FFR identified a best and worst ventricular pacing strategy for each patient, based on the AUC at baseline, submaximal, and peak heart rates (P < .001). However, there was no single best ventricular pacing strategy that was optimal for all patients. Additionally, the best ventricular pacing strategy often differed within the same patient at different heart rates.

CONCLUSION

This novel assessment demonstrates a wide variability in optimal ventricular pacing strategy. These inherent differences may play a role in the unpredictable clinical response to BiV pacing in CHD, and emphasizes an individualized approach. Furthermore, the optimal ventricular pacing varies with heart rate within individuals, suggesting that rate-responsive ventricular pacing modulation may be required to optimize ventricular performance.

Reduced long axis strain is associated with heart failure and cardiovascular events in the multi-ethnic study of Atherosclerosis

PURPOSE

To propose long axis strain (LAS), a novel index of global left ventricle (LV) function, as a sensitive and powerful predictor of hard cardiovascular events and heart failure in the Multi-Ethnic Study of Atherosclerosis (MESA).

MATERIALS AND METHODS

Strain is an index of relative myocardial deformation, and enables normalization for differences in heart size. Measurement of strain conventionally requires dedicated software and protocols for image acquisition. LAS, however, can be analyzed using a caliper tool from conventional LV long axis magnetic resonance imaging (MRI) cine loops, reflecting the average myocardial contraction in the longitudinal direction. In all, 1651 participants (53% men) of the MESA study, without a history of myocardial infarction or heart failure, were assessed using conventional cine MR images. LV lengths were assessed at end-diastole (EDL ) and end-systole (ESL ), and LAS was calculated as 100*(EDL -ESL )/EDL . Participants were followed for 6.8 ± 1.8 years for a composite endpoint of congestive heart failure or hard cardiovascular events, and the predictive ability of LAS was tested, unadjusted and adjusted for established cardiovascular risk factors.

RESULTS

A total of 114 events were observed. Mean LAS was 11.7 ± 2.5% and 10.0 ± 2.7% in participants without and with events, respectively (P < 0.001). Increased LAS reduced the hazard ratio to 0.75 for univariate, and 0.88 for multivariate assessments, respectively (both P < 0.001).

CONCLUSION

Assessment of long axis LV deformation by LAS is feasible and reproducible. Moreover, LAS predicts hard cardiovascular events and congestive heart failure in a multi-ethnic population without overt cardiovascular disease at inclusion. J. Magn. Reson. Imaging 2016;44:178-185.

Fast assessment of long axis strain with standard cardiovascular magnetic resonance: a validation study of a novel parameter with reference values

BACKGROUND

Assessment of longitudinal function with cardiovascular magnetic resonance (CMR) is limited to measurement of systolic excursion of the mitral annulus (MAPSE) or elaborate strain imaging modalities. The aim of this study was to develop a fast assessable parameter for the measurement of long axis strain (LAS) with CMR.

METHODS

40 healthy volunteers and 125 patients with different forms of cardiomyopathy were retrospectively analyzed. Four different approaches for the assessment of LAS with CMR measuring the distance between the LV apex and a line connecting the origins of the mitral valve leaflets in enddiastole and endsystole were evaluated. Values for LAS were calculated according to the strain formula.

RESULTS

LAS derived from the distance of the epicardial apical border to the midpoint of the line connecting the mitral valve insertion points (LAS-epi/mid) proved to be the most reliable parameter for the assessment of LAS among the different approaches. LAS-epi/mid displayed the highest sensitivity (81.6 %) and specificity (97.5 %), furthermore showing the best correlation with feature tracking (FTI) derived transmural longitudinal strain (r = 0.85). Moreover, LAS-epi/mid was non-inferior to FTI in discriminating controls from patients (Area under the curve (AUC) = 0.95 vs. 0.94, p = NS). The time required for analysis of LAS-epi/mid was significantly shorter than for FTI (67 ± 8 s vs. 180 ± 14 s, p < 0.0001). Additionally, LAS-epi/mid performed significantly better than MAPSE (Delta AUC = 0.09; p < 0.005) and the ejection fraction (Delta AUC = 0.11; p = 0.0002). Reference values were derived from 234 selected healthy volunteers. Mean value for LAS-epi/mid was -17.1 ± 2.3 %. Mean values for men were significantly lower compared to women (-16.5 ± 2.2 vs. -17.9 ± 2.1 %; p < 0.0001), while LAS decreased with age.

CONCLUSIONS

LAS-epi/mid is a novel and fast assessable parameter for the analysis of global longitudinal function with non-inferiority compared to transmural longitudinal strain.

Usefulness of traditional echocardiographic parameters in assessment of left ventricular function in patients with normal ejection fraction early after acute myocardial infarction: results from a large consecutive cohort

AIMS

The aim of this study was to assess the frequency of left ventricular (LV) systolic function impairment using classical echocardiographic parameters and their relation to myocardial damage in patients hospitalized for acute myocardial infarction (MI) with normal LV ejection fraction (LVEF ≥52% in males or ≥54% in females).

METHODS AND RESULTS

All 421 consecutive patients with MI included in the REBUS (RElevance of Biomarkers for future risk of thromboembolic events in UnSelected post-myocardial infarction patients) study underwent two-dimensional and Doppler echocardiography within 72 h after admission. A normal LVEF was present in 262 (73.8%) of the 355 patients ultimately enrolled in the study. Patients with normal LVEF more often presented with non-ST-elevation myocardial infarction and had less comorbidities when compared with those with impaired LVEF. No differences in demographic factors or relevant medications were observed. Higher value of mean annular plane systolic excursion (MAPSE), lower wall motion score index (WMSI), lower LV as well as left atrial volumes characterized patients with normal LVEF. Impaired MAPSE was present in 64.4%, WMSI >1 in 72.1%, and dilated left atrium in 33.6% of those patients. Maximal cardiac troponin concentration reflecting infarct size showed the strongest association with WMSI (β = 0.35), followed by LVEF (β = -0.29), MAPSE (β = -0.25), and indexed LV end-systolic volume (β = 0.19; P < 0.001 for all the models).

CONCLUSION

In two-third of patients with MI and normal LVEF, at least one of the other markers of systolic function was outside of the normal range. WMSI reflected the size of MI better than global LV function parameters as LVEF or MAPSE.

Long axis strain by MRI and echocardiography in a postmyocardial infarct population

PURPOSE

To compare long axis strain (LAS) by magnetic resonance imaging (MRI) and echocardiography in a postinfarct patient population. Long axis left ventricle (LV) function is a sensitive index of incipient heart failure by echocardiography, but is less well established in MRI. LAS is an index of global LV function, which is easily assessed in cine loops provided by most cardiac MRI protocols.

MATERIALS AND METHODS

In all, 116 patients (57 ± 9 years) were studied the same day using echocardiography and MRI 7.4 ± 4.1 months after a first myocardial infarction. LV length was measured in end diastole and end systole in conventional cine images with a temporal resolution of 50 msec or less, and LAS (%) was calculated as the change in LV length, relative to end diastole. Infarct mass was assessed by contrast-enhanced MRI.

RESULTS

LAS was progressively reduced in patients with larger infarcts, and demonstrated good correlations with infarct mass (r = 0.55, P < 0.01). There was a good agreement between LAS assessed by echocardiography and MRI (r = 0.77, P < 0.01), and between LAS by MRI and speckle tracking strain by echocardiography (r = 0.74, P < 0.01).

CONCLUSION

LAS is an index that allows measurement of LV long axis function by conventional cine MRI.

Mitral annular displacement by Doppler tissue imaging may identify coronary occlusion and predict mortality in patients with non-ST-elevation myocardial infarction

BACKGROUND

Mitral annular displacement (MAD) is a simple marker of left ventricular (LV) systolic function. The aim of this study was to test the hypothesis that MAD can distinguish patients with non-ST-segment elevation myocardial infarctions (NSTEMIs) from those with significant coronary artery disease without infarctions, identify coronary occlusion, and predict mortality in patients with NSTEMIs. MAD was compared with established indices of LV function.

METHODS

In this retrospective study, 167 patients with confirmed NSTEMIs were included at two Scandinavian centers. Forty patients with significant coronary artery disease but without myocardial infarctions were included as controls. Doppler tissue imaging was performed at the mitral level of the left ventricle in the three apical planes, and velocities were integrated over time to acquire MAD. LV ejection fraction, global longitudinal strain (GLS), and wall motion score index were assessed according to guidelines.

RESULTS

MAD and GLS could accurately distinguish patients with NSTEMIs from controls. During 48.6 ± 12.1 months of follow-up, 22 of 167 died (13%). MAD, LV ejection fraction, and GLS were reduced and wall motion score index was increased among those who died compared with those who survived (P < .001, P < .001, P < .001, and P = .02, respectively). Multivariate Cox proportional-hazards analyses revealed that MAD was an independent predictor of death (hazard ratio, 1.36; 95% confidence interval, 1.07-1.73; P = .01). MAD and GLS were reduced and wall motion score index was increased in patients with coronary artery occlusion compared with those without occlusion (P = .006, P = .001, and P = .02), while LV ejection fraction did not differ (P = .20).

CONCLUSIONS

MAD accurately identified patients with NSTEMIs, predicted mortality, and identified coronary occlusion in patients with NSTEMIs.

Speckle tracking echocardiography-determined measures of global and regional left ventricular function correlate with functional capacity in patients with and without preserved ejection fraction

Background

Standard measures of left ventricular systolic and diastolic function often fail to identify left ventricular dysfunction in patients with heart failure and do not correlate with measures of functional capacity.

Aim

To determine if speckle tracking echocardiography (STE)–determined measures of global and regional myocardial contractility have a linear association with functional capacity in patients with and without preserved ejection fraction.

Methods

In 68 adult patients, functional status was estimated with the Duke Activity Status Index (DASI), left ventricular ejection fraction was determined with Simpson’s biplane method, and QLAB advanced quantification software (Philips, The Netherlands) was used to determine peak measures of strain.

Results

Global and regional measures of longitudinal, circumferential, and radial strain had a strong linear association with the DASI score. Longitudinal strain in the inferolateral segments had the strongest correlation with DASI (r = −0.72, P < 0.001). In patients with an ejection fraction ≥45%, ejection fraction and E/e’ had no correlation with DASI, whereas longitudinal strain in the inferolateral segments had significant correlation with DASI (r = −0.53, P = 0.03, n = 16).

Conclusions

STE–determined measures of global and regional left ventricular function have a strong linear association with estimates of functional capacity in patients with and without preserved ejection fraction. STE–determined measures of strain, especially longitudinal strain, are likely to be important targets for therapy and should be considered in future studies aimed at improving our diagnosis of left ventricular inadequacy in patients with heart failure, especially those with preserved ejection fraction.

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.

Longitudinal myocardial contribution to peak systolic flow and stroke volume in the neonatal heart

Systolic longitudinal myocardial function is important for cardiac ejection. Data describing hemodynamic determinants and the time course of myocardial longitudinal contraction as measured by tissue Doppler are lacking. Ten newborn pigs were used for invasive hemodynamic investigation. Tissue Doppler assessment of the lateral part of the mitral valve annulus during systole was performed during pharmacological modulation of inotropy, cardiac pacing, and modulations of loading conditions. The strongest association was found between peak systolic velocity (S') and peak systolic flow (PSF) and end-systolic pressure (ESP), respectively (β = 0.09 cm/mL, p < 0.001 and β = -0.07 cm/mL, p = 0.003). Displacement (D) was mostly influenced by stroke volume (SV) (β = 0.05 cm/mL, p < 0.001). Ejection time, SV, ESP, maximum first derivative of pressure (dP/dtmax), and PSF were all associated with S' and D under different states of hemodynamic modulation; however, the ratio between PSF and S', SV, and D were stable during hemodynamic modulations. Normalized cross correlations indicate that S' and D follow the same trajectory as flow and SV, respectively. In conclusion, this study provides validity of accounting systolic D in the long axis as the longitudinal contribution to SV and peak systolic tissue velocity as the longitudinal contribution to PSF.

Detection of left ventricular dysfunction by global longitudinal systolic strain in patients with chronic aortic regurgitation

BACKGROUND

The purpose of this study was to investigate whether global longitudinal strain measured by two-dimensional speckle tracking echocardiography could detect incipient myocardial dysfunction in patients with chronic aortic regurgitation (AR). Disclosing left ventricular (LV) dysfunction is of decisive importance for optimal timing of surgery but challenging because of the altered loading conditions.

METHODS

Forty-seven patients referred for aortic valve replacement because of chronic AR were studied, along with 31 healthy controls. Myocardial deformation as determined by longitudinal, circumferential, and radial strain was calculated using two-dimensional speckle-tracking echocardiography technique, in addition to LV volumes, dimensions, and ejection fraction. Strain values were normalized to end-diastolic volume to correct for the volume dependency of deformation.

RESULTS

Global systolic longitudinal strain was significantly lower in patients with AR before surgery compared with the healthy controls (-17.5 ± 3.1% vs -22.1 ± 1.8%, P < .01), while global circumferential strain and LV ejection fraction did not differ (-21.7 ± 3.4% vs -22.6 ± 2.5%, P = .22 and 59 ± 5% vs 59 ± 6%, P = .59, respectively). However, differences between patients and controls were evident for both longitudinal and circumferential strain when normalized to end-diastolic volume (-0.09 ± 0.04 vs -0.23 ± 0.08, P < .01, and -0.11 ± 0.05 vs -0.24 ± 0.08, P < .01, respectively). In contrast to their absolute values, both normalized variables demonstrated improvement in myocardial shortening after valve replacement (P < .01).

CONCLUSIONS

The study demonstrated reduced global longitudinal strain in patients with chronic AR with preserved LV ejection fractions. Global longitudinal strain might therefore disclose incipient myocardial dysfunction with a consequent potential for improved timing of aortic valve surgery.

In vivo porcine left atrial wall stress: Computational model

Most computational models of the heart have so far concentrated on the study of the left ventricle, mainly using simplified geometries. The same approach cannot be adopted to model the left atrium, whose irregular shape does not allow morphological simplifications. In addition, the deformation of the left atrium during the cardiac cycle strongly depends on the interaction with its surrounding structures. We present a procedure to generate a comprehensive computational model of the left atrium, including physiological loads (blood pressure), boundary conditions (pericardium, pulmonary veins and mitral valve annulus movement) and mechanical properties based on planar biaxial experiments. The model was able to accurately reproduce the in vivo dynamics of the left atrium during the passive portion of the cardiac cycle. A shift in time between the peak pressure and the maximum displacement of the mitral valve annulus allows the appendage to inflate and bend towards the ventricle before the pulling effect associated with the ventricle contraction takes place. The ventricular systole creates room for further expansion of the appendage, which gets in close contact with the pericardium. The temporal evolution of the volume in the atrial cavity as predicted by the finite element simulation matches the volume changes obtained from CT scans. The stress field computed at each time point shows remarkable spatial heterogeneity. In particular, high stress concentration occurs along the appendage rim and in the region surrounding the pulmonary veins.

Evaluation of right ventricular dysfunction by myocardial strain echocardiography in patients with intestinal carcinoid disease

BACKGROUND

Cardiac fibrosis is an important complication of intestinal carcinoid disease, with resulting valvular and ventricular dysfunction due to endocardial fibrosis. Evaluation of right ventricular (RV) function in these patients has focused on valvular involvement. The aim of this study was to investigate whether myocardial strain by echocardiography can detect RV dysfunction in patients with carcinoid disease.

METHODS

Eighty-nine patients with intestinal carcinoid and 50 healthy individuals were studied. Strain measurements were assessed by speckle-tracking echocardiography. The average of the three lateral RV segments was calculated as RV strain. Left ventricular global strain was calculated from a 16-segment model.

RESULTS

Carcinoid heart disease was present in 15 of the 89 patients. RV strain was reduced in patients with carcinoid disease compared with healthy controls (-20.6 ± 5.0% vs -26.9 ± 4.4%, P < .001). RV function by strain was not significantly different in patients with and without carcinoid heart disease (-21.2 ± 5.7% vs -20.5 ± 4.8%, P = .59). Excluding patients with overt carcinoid heart disease, RV strain was reduced in patients with 5-hydroxyindoleacetic acid levels above the normal range compared with those with levels within the normal range (-19.4 ± 5.4 vs -21.6 ± 3.7%, P = .05).

CONCLUSIONS

RV function by myocardial strain was reduced in patients with carcinoid disease independently of valvular involvement. This indicates that myocardial strain by echocardiography provides added information about RV function in patients with intestinal carcinoid disease.

Longitudinal peak strain detects a smaller risk area than visual assessment of wall motion in acute myocardial infarction

BACKGROUND

Opening of an occluded infarct related artery reduces infarct size and improves survival in acute ST-elevation myocardial infarction (STEMI). In this study we performed tissue Doppler analysis (peak strain, displacement, mitral annular movement (MAM)) and compared with visual assessment for the study of the correlation of measurements of global, regional and segmental function with final infarct size and transmurality. In addition, myocardial risk area was determined and a prediction sought for the development of infarct transmurality >or=50%.

METHODS

Twenty six patients with STEMI submitted for primary percutaneous coronary intervention (PCI) were examined with echocardiography on the catheterization table. Four to eight weeks later repeat echocardiography was performed for reassessment of function and magnetic resonance imaging for the determination of final infarct size and transmurality.

RESULTS

On a global level, wall motion score index (WMSI), ejection fraction (EF), strain, and displacement all showed significant differences (p <or= 0.001, p <or= 0.001, p <or= 0.001 and p = 0.03) between the two study visits, but MAM did not (p = 0.17). On all levels (global, regional and segmental) and both pre- and post PCI, WMSI showed a higher correlation with scar transmurality compared to strain. We found that both strain and WMSI predicted the development of scar transmurality >or=50%, but strain added no significant information to that obtained with WMSI in a logistic regression analysis.

CONCLUSIONS

In patients with acute STEMI, WMSI, EF, strain, and displacement showed significant changes between the pre- and post PCI exam. In a ROC-analysis, strain had 64% sensitivity at 80% specificity and WMSI around 90% sensitivity at 80% specificity for the detection of scar with transmurality >or=50% at follow-up.

Functional measurements based on feature tracking of cine magnetic resonance images identify left ventricular segments with myocardial scar

BACKGROUND

The aim of the study was to perform a feature tracking analysis on cine magnetic resonance (MR) images to elucidate if functional measurements of the motion of the left ventricular wall may detect scar defined with gadolinium enhanced MR.Myocardial contraction can be measured in terms of the velocity, displacement and local deformation (strain) of a particular myocardial segment. Contraction of the myocardial wall will be reduced in the presence of scar and as a consequence of reduced myocardial blood flow.

METHODS

Thirty patients (3 women and 27 men) were selected based on the presence or absence of extensive scar in the anteroseptal area of the left ventricle. The patients were investigated in stable clinical condition, 4-8 weeks post ST-elevation myocardial infarction treated with percutaneous coronary intervention. Seventeen had a scar area >75% in at least one anteroseptal segment (scar) and thirteen had scar area <1% (non-scar). Velocity, displacement and strain were calculated in the longitudinal direction, tangential to the endocardial outline, and in the radial direction, perpendicular to the tangent.

RESULTS

In the scar patients, segments with scar showed lower functional measurements than remote segments. Radial measurements of velocity, displacement and strain performed better in terms of receiver-operator-characteristic curves (ROC) than the corresponding longitudinal measurements. The best area-under-curve was for radial strain, 0.89, where a cut-off value of 38.8% had 80% sensitivity and 86% specificity for the detection of a segment with scar area >50%. As a percentage of the mean, intraobserver variability was 16-14-26% for radial measurements of displacement-velocity-strain and corresponding interobserver variability was 13-12-18%.

CONCLUSION

Feature tracking analysis of cine-MR displays velocity, displacement and strain in the radial and longitudinal direction and may be used for the detection of transmural scar. The accuracy and repeatability of the radial functional measurements is satisfactory and global measures agree.