Showing papers by "Jens-Uwe Voigt published in 2018"

Standardization of left atrial, right ventricular, and right atrial deformation imaging using two-dimensional speckle tracking echocardiography: a consensus document of the EACVI/ASE/Industry Task Force to standardize deformation imaging.

Abstract: The EACVI/ASE/Industry Task Force to standardize deformation imaging prepared this consensus document to standardize definitions and techniques for using two-dimensional (2D) speckle tracking echocardiography (STE) to assess left atrial, right ventricular, and right atrial myocardial deformation. This document is intended for both the technical engineering community and the clinical community at large to provide guidance on selecting the functional parameters to measure and how to measure them using 2D STE.This document aims to represent a significant step forward in the collaboration between the scientific societies and the industry since technical specifications of the software packages designed to post-process echocardiographic datasets have been agreed and shared before their actual development. Hopefully, this will lead to more clinically oriented software packages which will be better tailored to clinical needs and will allow industry to save time and resources in their development.

Variability and Reproducibility of Segmental Longitudinal Strain Measurement: A Report From the EACVI-ASE Strain Standardization Task Force

Abstract: Objectives In this study, we compared left ventricular (LV) segmental strain measurements obtained with different ultrasound machines and post-processing software packages. Background Global longitudinal strain (GLS) has proven to be a reproducible and valuable tool in clinical practice. Data about the reproducibility and intervendor differences of segmental strain measurements, however, are missing. Methods We included 63 volunteers with cardiac magnetic resonance–proven infarct scar with segmental LV function ranging from normal to severely impaired. Each subject was examined within 2 h by a single expert sonographer with machines from multiple vendors. All 3 apical views were acquired twice to determine the test-retest and the intervendor variability. Segmental longitudinal peak systolic, end-systolic, and post-systolic strain were measured using 7 vendor-specific systems (Hitachi, Tokyo, Japan; Esaote, Florence, Italy; GE Vingmed Ultrasound, Horten, Norway; Philips, Andover, Massachusetts; Samsung, Seoul, South Korea; Siemens, Mountain View, California; and Toshiba, Otawara, Japan) and 2 independent software packages (Epsilon, Ann Arbor, Michigan; and TOMTEC, Unterschleissheim, Germany) and compared among vendors. Results Image quality and tracking feasibility differed among vendors (analysis of variance, p Conclusions In contrast to GLS, LV segmental longitudinal strain measurements have a higher variability on top of the known intervendor bias. The fidelity of different software to follow segmental function varies considerably. We conclude that single segmental strain values should be used with caution in the clinic. Segmental strain pattern analysis might be a more robust alternative.

Intervendor Differences in the Accuracy of Detecting Regional Functional Abnormalities: A Report From the EACVI-ASE Strain Standardization Task Force.

Abstract: Objectives The purpose of this study was to compare the accuracy of vendor-specific and independent strain analysis tools to detect regional myocardial function abnormality in a clinical setting. Background Speckle tracking echocardiography has been considered a promising tool for the quantitative assessment of regional myocardial function. However, the potential differences among speckle tracking software with regard to their accuracy in identifying regional abnormality has not been studied extensively. Methods Sixty-three subjects (5 healthy volunteers and 58 patients) were examined with 7 different ultrasound machines during 5 days. All patients had experienced a previous myocardial infarction, which was characterized by cardiac magnetic resonance with late gadolinium enhancement. Segmental peak systolic (PS), end-systolic (ES) and post-systolic strain (PSS) measurements were obtained with 6 vendor-specific software tools and 2 independent strain analysis tools. Strain parameters were compared between fully scarred and scar-free segments. Receiver-operating characteristic curves testing the ability of strain parameters and derived indexes to discriminate between these segments were compared among vendors. Results The average strain values calculated for normal segments ranged from −15.1% to −20.7% for PS, −14.9% to −20.6% for ES, and −16.1% to −21.4% for PSS. Significantly lower values of strain (p Conclusions The accuracy of identifying regional abnormality differs significantly among vendors.

Left ventricular global myocardial strain assessment comparing the reproducibility of four commercially available CMR-feature tracking algorithms

Abstract: To compare the reproducibility of cardiovascular magnetic resonance feature-tracking (CMR-FT) packages to assess global left ventricular (LV) myocardial strain. In 45 subjects (i.e. 15 controls, 15 acute myocardial infarction, 15 dilated cardiomyopathy patients), we determined inter-vendor, inter-observer (two readers) and intra-observer reproducibility of peak systolic global radial, circumferential and longitudinal strain (GRS, GCS and GLS, respectively) comparing four commercially available software packages. Differences between vendors were assessed with analysis of variance (ANOVA), between observers and readings with intraclass correlation coefficient (ICC) and coefficient of variation (CV). The normalised end-diastolic volume was 91, 77 and 119 ml/m2 (median, Q1, Q3) and ejection fraction was 41 ± 14%, range 12-67%. Global longitudinal strain (GLS), global circumferential strain (GCS) and global radial strain (GRS) values were 13.9% ± 5.4% (3.9-23.8%), 12.2% ± 5.8% (1.0-25.1%) and 32.0% ± 14.7 (3.6-67.8%), respectively. ANOVA showed significant differences between vendors for GRS (p < 0.001) and GLS (p = 0.018), not for GCS (p = 0.379). No significant bias was found for both intra- and inter-observer variability. The ICC for inter- and intra-observer reproducibility ranged 0.828-0.991 and 0.902-0.997, respectively. The CV, however, ranged considerably, i.e. 4.0-28.8% and 2.8- 27.7% for inter- and intra-observer reproducibility, respectively. In particular, for GRS differences in CV values between vendors were large, i.e. 5.2-28.8% and 2.8-27.7%, for inter- and intra-observer reproducibility, respectively. In a cohort of subjects with a wide range of cardiac performances, GRS and GLS values are not interchangeable between vendors. Moreover, although intra- and inter-observer reproducibility amongst vendors is excellent, some vendors encounter problems to reproducibly measure global radial strain. • Different software packages are currently available for myocardial strain assessment using routinely acquired cine CMR images. • Global myocardial strain values are not interchangeable between vendors for global longitudinal and global radial strain. • Inter- and intra-observer reproducibility for global strain assessment is excellent. However, some vendors encounter problems to reproducibly measure global radial strain.

Timing of myocardial shortening determines left ventricular regional myocardial work and regional remodelling in hearts with conduction delays.

Abstract: Aims The interaction between asynchronous regional myocardial activation and left ventricular (LV) wall remodelling has not been well established. We investigated the relationship between time of onset of longitudinal shortening (Tonset), regional myocardial work, and segmental LV wall thickness (SWT) in patients treated with cardiac resynchronization therapy (CRT). Methods and results We analysed 26 patients with sinus rhythm, non-ischaemic cardiomyopathy (63 ± 9 years, 69% male, QRS duration 174 ± 18 ms) and positive response to CRT (15% reduction in end-systolic volume). Longitudinal strain was obtained by 2D speckle-tracking echocardiography before and after [14.5 (7-29) months] CRT. Tonset and SWT were measured in 18 segments per LV. Segmental myocardial work was calculated from non-invasive segmental stress-strain loop area. Before CRT, Tonset was the shortest in septal and anteroseptal and the longest in lateral and posterior walls (P < 0.001) and not different after CRT (P = 0.733). Before CRT, septal and anteroseptal walls were significantly thinner than lateral and posterior. After CRT, reverse remodelling increased thickness in septal and anteroseptal and thinned lateral and posterior segments (P < 0.001). Before CRT, non-uniformity in work distribution with reduced work in septal and anteroseptal and increased work in lateral and posterior walls (P < 0.001) was observed. After CRT, distribution of myocardial work was uniform (P = 0.215). Conclusion Dys-synchronous myocardial shortening is related to thinning of early and thickening of late activated segments in heart failure with conduction delay. Correction of dys-synchrony leads to regression of inhomogeneity towards more evenly distributed wall thickness. Regional differences in myocardial work load that are homogenized by successful CRT are considered as the underlying pathophysiological mechanism.

Epidemiologic observations guiding clinical application of a urinary peptidomic marker of diastolic left ventricular dysfunction.

Abstract: Hypertension, obesity, and old age are major risk factors for left ventricular (LV) diastolic dysfunction (LVDD), but easily applicable screening tools for people at risk are lacking. We investigated whether HF1, a urinary biomarker consisting of 85 peptides, can predict over a 5-year time span mildly impaired diastolic LV function as assessed by echocardiography. In 645 white Flemish (50.5% women; 50.9 years [mean]), we measured HF1 by capillary electrophoresis coupled with mass spectrometry in 2005-2010. We measured early (E) and late (A) peak velocities of the transmitral blood flow and early (e') and late (a') mitral annular peak velocities and their ratios in 2009-2013. In multivariable-adjusted analyses, per 1-standard deviation increment in HF1, e' was -0.193 cm/s lower (95% confidence interval: -0.352 to -0.033; P = .018) and E/e' 0.174 units higher (0.005-0.342; P = .043). Of 645 participants, 179 (27.8%) had LVDD at follow-up, based on impaired relaxation in 69 patients (38.5%) or an elevated filling pressure in the presence of a normal (74 [43.8%]) or low (36 [20.1%]) age-specific E/A ratio. For a 1-standard deviation increment in HF1, the adjusted odds ratio was 1.37 (confidence interval, 1.07-1.76; P = .013). The integrated discrimination (+1.14%) and net reclassification (+31.7%) improvement of the optimized HF1 threshold (-0.350) in discriminating normal from abnormal diastolic LV function at follow-up over and beyond other risk factors was significant (P ≤ .024). In conclusion, HF1 may allow screening for LVDD over a 5-year horizon in asymptomatic people.

Sensitive and stable vector magnetometer for operation in zero and finite fields.

Abstract: We report on an optically pumped magnetometer that uses multiple laser beams to pump and probe spin-polarized Cs atoms. The selected sensor geometry allows for operation in finite magnetic fields as well as close to zero field. In finite fields the magnetometer employs free spin precession signals to determine the field modulus and direction as described in a separate publication. This publication focuses on the magnetometer operation close to zero field, which is based on a ground state Hanle resonance. The four laser beams permit the simultaneous measurement of two orthogonal magnetic field components in a differential detection scheme that greatly suppresses technical laser power noise. Sensitivities better than 54 fT/Hz1/2 could be demonstrated simultaneously for both measurement channels in a well shielded environment. A minimum Allan deviation, limited by residual field fluctuations, of better than 40 fT was observed for integration times of 2s. The magnetometer achieves high sensitivity and stability in offset fields as well as close to zero field and is, thus, a universal tool for low frequency magnetic field measurements.

nEDM experiment at PSI: data-taking strategy and sensitivity of the dataset

Abstract: We report on the strategy used to optimize the sensitivity of our search for a neutron electric dipole moment at the Paul Scherrer Institute. Measurements were made upon ultracold neutrons stored within a single chamber at the heart of our apparatus. A mercury cohabiting magnetometer together with an array of cesium magnetometers were used to monitor the magnetic field, which was controlled and shaped by a series of precision field coils. In addition to details of the setup itself, we describe the chosen path to realize an appropriate balance between achieving the highest statistical sensitivity alongside the necessary control on systematic effects. The resulting irreducible sensitivity is better than 1*10-26 ecm. This contribution summarizes in a single coherent picture the results of the most recent publications of the collaboration.

Advanced Imaging to Phenotype Patients With a Systemic Right Ventricle.

Abstract: Background Reduced ventricular function and decreased exercise capacity are widespread in adults with complete transposition of the great arteries after atrial switch (TGA‐Mustard/Senning) and cong...

Validation of a Novel Software Tool for Automatic Aortic Annular Sizing in Three-Dimensional Transesophageal Echocardiographic Images

Abstract: Background Accurate aortic annulus (AoA) sizing is crucial for transcatheter aortic valve implantation planning. Three-dimensional (3D) transesophageal echocardiography (TEE) is a viable alternative to the standard multidetector row computed tomography (MDCT) for such assessment, with few automatic software solutions available. The aim of this study was to present and evaluate a novel software tool for automatic AoA sizing by 3D TEE. Methods One hundred one patients who underwent both preoperative MDCT and 3D TEE were retrospectively analyzed using the software. The automatic software measurements' accuracy was compared against values obtained using standard manual MDCT, as well as against those obtained using manual 3D TEE, and intraobserver, interobserver, and test-retest reproducibility was assessed. Because the software can be used as a fully automatic or as an interactive tool, both options were addressed and contrasted. The impact of these measures on the recommended prosthesis size was then evaluated to assess if the software's automated sizes were concordant with those obtained using an MDCT- or a TEE-based manual sizing strategy. Results The software showed very good agreement with manual values obtained using MDCT and 3D TEE, with the interactive approach having slightly narrower limits of agreement. The latter also had excellent intra- and interobserver variability. Both fully automatic and interactive analyses showed excellent test-retest reproducibility, with the first having a faster analysis time. Finally, either approach led to good sizing agreement against the true implanted sizes (>77%) and against MDCT-based sizes (>88%). Conclusions Given the automated, reproducible, and fast nature of its analyses, the novel software tool presented here may potentially facilitate and thus increase the use of 3D TEE for preoperative transcatheter aortic valve implantation sizing.

Reversibility of severe mitral valve regurgitation after left ventricular assist device implantation: single-centre observations from a real-life population of patients.

Abstract: OBJECTIVES This study evaluates the impact of untreated preoperative severe mitral valve regurgitation (MR) on outcomes after left ventricular assist device (LVAD) implantation. METHODS Of the 234 patients who received LVAD therapy in our centre during a 6-year period, we selected those who had echocardiographic images of good quality and excluded those who underwent mitral valve replacement prior to or mitral valve repair during LVAD placement. The 128 patients selected were divided into 2 groups: Group A with severe MR (n = 65) and Group B with none to moderate MR (n = 63, 28 with moderate MR). We evaluated transthoracic echocardiography preoperatively [15 (7-28) days before LVAD implantation; median (interquartile range)] and postoperatively up to the last available follow-up [501 (283-848) days after LVAD]. We collected mortality, complications and clinical status indicators of the patient cohort. RESULTS We observed a significant decrease in the severity of MR after LVAD implantation (severe MR 51% pre- vs 6% post-LVAD implantation, P < 0.001). There was no difference between groups in terms of right heart failure, rate of urgent heart transplantation, pump thrombosis or ventricular arrhythmias. There was no difference in 1-year survival and 3-year survival (87.7% vs 88.4% and 71.8% vs 66.6% for Groups A and B, respectively, P = 0.97). CONCLUSIONS Preoperative severe MR resolves in the majority of patients early on after LVAD implantation and is not associated with worse clinical outcomes or intermediate-term survival.

Evaluation of Coherence-Based Beamforming for B-Mode and Speckle Tracking Echocardiography

Abstract: Phase coherence methods have been proposed to improve the delay-and-sum (DAS) beamforming in terms of contrast and spatial resolution. However, they could be equally beneficial for speckle tracking echocadiography, given the higher variance they introduce in the speckle texture. The aim of this study was to compare, in a close-to-clinical scenario, the B-mode and speckle tracking performance of the DAS beamformer and 4 phase coherence methods: generalized coherence factor, phase coherence factor, sign coherence factor and short lag spatial coherence. Both simulation and experimental imaging of a tissue mimicking phantom were used to assess classical imaging metrics, whereas in-vivo imaging was performed to evaluate myocardial visibility and tissue tracking. Results showed improved resolution and contrast from the coherence beamformers, as well as a reduction of clutter noise, especially in the near field. Similarly, apical strain curves were more reliably estimated following coherence processing. Overall, these methods seem to better derive both morphological and functional imaging, although no method outperformed in all scenarios.

Machine Learning for Quality Assurance of Myocardial Strain Curves

Abstract: Speckle tracking echocardiography (STE) is a well-established technique to quantify regional myocardial function. Reliability of STE-derived strain curves, however, depends strongly on the quality of the acquired B-mode images and can significantly be influenced by image artifacts. Artifactual images could lead to tracking errors and as a result, the measured deformation patterns might be similar to those obtained in pathology. It would thus be clinically very relevant to get feedback on the reliability (i.e. quality) of the extracted strain curves. As such, the aim of this study was to examine the utility of machine learning in the identification of artifactual strain curves. Our proposed learning framework was built upon a data imputation algorithm in order to facilitate the task of classifying (non-)artifactual curves. The obtained results confirmed the feasibility of automatic quality assurance of the STE-derived strain curves via machine learning.

Pulmonary vein signal in mitral regurgitation.

Abstract: We read the article Critical care ultrasonography in acute respiratory failure [1] by Vignon et al. with great interest. We agree that echocardiography plays an important role in the evaluation of patients with acute respiratory failure. We do not, however, agree with the statement that massive mitral regurgitation causes a reversal in pulmonary vein diastolic inflow or “D wave” as implied in Figure 2 where a case of cardiac weaning failure is presented. Since mitral regurgitation is a systolic phenomenon it can only cause reversal of the systolic “S wave” [2]. This is actually shown in the right lower panel of the figure, where the arrow points at a reversed “S wave”. The “S” and “D” labels should be exchanged and the figure legend should be corrected accordingly.

Rocking makes the difference.

Abstract: Rocking makes the difference Maass et al. introduced the CAVIAR response score as a tool for improving patient selection for cardiac resynchronization therapy (CRT). It is interesting to read, that apical rocking, a simple mechanical dyssynchrony marker, was an independent predictor of volumetric response to CRT and was proposed as one of the four scoring parameters. We would like to congratulate the authors to this study which confirms to a great extend our 1000-patient, multi-centre experience reported in the PREDICT-CRT study which investigated the relationship of apical rocking and septal flash to clinical outcomes following CRT. Both apical rocking and septal flash were associated with volumetric response and survival and also had a significant incremental value over clinical variables for the prediction of CRT response. Of note, almost identical association of apical rocking and response to CRT was simultaneously reported by other, smaller studies and it will hopefully be confirmed by the ongoing EuroCRT study. The study by Maas et al. is important as it reflects a reviving enthusiasm for refining guideline-proposed criteria for CRT patient selection and adds to the existing evidence that simple, but robust parameters of left ventricular mechanical dyssynchrony may still work.