Integration of genomic and clinical data augments surveillance of healthcare-acquired infections.

BACKGROUND: Determining infectious cross-transmission events in healthcare settings involves manual surveillance of case clusters by infection control personnel, followed by strain typing of clinical/environmental isolates suspected in said clusters. Recent advances in genomic sequencing and cloud computing now allow for the rapid molecular typing of infecting isolates. OBJECTIVE: To facilitate rapid recognition of transmission clusters, we aimed to assess infection control surveillance using whole-genome sequencing (WGS) of microbial pathogens to identify cross-transmission events for epidemiologic review. METHODS: Clinical isolates of Staphylococcus aureus, Enterococcus faecium, Pseudomonas aeruginosa, and Klebsiella pneumoniae were obtained prospectively at an academic medical center, from September 1, 2016, to September 30, 2017. Isolate genomes were sequenced, followed by single-nucleotide variant analysis; a cloud-computing platform was used for whole-genome sequence analysis and cluster identification. RESULTS: Most strains of the 4 studied pathogens were unrelated, and 34 potential transmission clusters were present. The characteristics of the potential clusters were complex and likely not identifiable by traditional surveillance alone. Notably, only 1 cluster had been suspected by routine manual surveillance. CONCLUSIONS: Our work supports the assertion that integration of genomic and clinical epidemiologic data can augment infection control surveillance for both the identification of cross-transmission events and the inclusion of missed and exclusion of misidentified outbreaks (ie, false alarms). The integration of clinical data is essential to prioritize suspect clusters for investigation, and for existing infections, a timely review of both the clinical and WGS results can hold promise to reduce HAIs. A richer understanding of cross-transmission events within healthcare settings will require the expansion of current surveillance approaches.

Automated detection of coarctation of aorta in neonates from two-dimensional echocardiograms.

Coarctation of aorta (CoA) is a critical congenital heart defect (CCHD) that requires accurate and immediate diagnosis and treatment. Current newborn screening methods to detect CoA lack both in sensitivity and specificity, and when suspected in a newborn, it must be confirmed using specialized imaging and expert diagnosis, both of which are usually unavailable at tertiary birthing centers. We explore the feasibility of applying machine learning methods to reliably determine the presence of this difficult-to-diagnose cardiac abnormality from ultrasound image data. We propose a framework that uses deep learning-based machine learning methods for fully automated detection of CoA from two-dimensional ultrasound clinical data acquired in the parasternal long axis view, the apical four chamber view, and the suprasternal notch view. On a validation set consisting of 26 CoA and 64 normal patients our algorithm achieved a total error rate of 12.9% (11.5% false-negative error and 13.6% false-positive error) when combining decisions of classifiers over three standard echocardiographic view planes. This compares favorably with published results that combine clinical assessments with pulse oximetry to detect CoA (71% sensitivity).

Three-Dimensional Echocardiographic Assessment of Left Heart Chamber Size and Function with Fully Automated Quantification Software in Patients with Atrial Fibrillation.

BACKGROUND: Echocardiographic determination of left heart chamber volumetric parameters by using manual tracings during multiple beats is tedious in atrial fibrillation (AF). The aim of this study was to determine the usefulness of fully automated left chamber quantification software with single-beat three-dimensional transthoracic echocardiographic data sets in patients with AF. METHODS: Single-beat full-volume three-dimensional transthoracic echocardiographic data sets were prospectively acquired during consecutive multiple cardiac beats (≥10 beats) in 88 patients with AF. In protocol 1, left ventricular volumes, left ventricular ejection fraction, and maximal left atrial volume were validated using automated quantification against the manual tracing method in identical beats in 10 patients. In protocol 2, automated quantification-derived averaged values from multiple beats were compared with the corresponding values obtained from the indexed beat in all patients. RESULTS: Excellent correlations of left chamber parameters between automated quantification and the manual method were observed (r = 0.88-0.98) in protocol 1. The time required for the analysis with the automated quantification method (5 min) was significantly less compared with the manual method (27 min) (P < .0001). In protocol 2, there were excellent linear correlations between the averaged left chamber parameters and the corresponding values obtained from the indexed beat (r = 0.94-0.99), and test-retest variability of left chamber parameters was low (3.5%-4.8%). CONCLUSIONS: Three-dimensional transthoracic echocardiography with fully automated quantification software is a rapid and reliable way to measure averaged values of left heart chamber parameters during multiple consecutive beats. Thus, it is a potential new approach for left chamber quantification in patients with AF in daily routine practice.

Using Anatomic Intelligence to Localize Mitral Valve Prolapse on Three-Dimensional Echocardiography.

BACKGROUND: Accurate localization of mitral valve prolapse (MVP) is crucial for surgical planning. Despite improved visualization of the mitral valve by three-dimensional transesophageal echocardiography, image interpretation remains expertise dependent. Manual construction of mitral valve topographic maps improves diagnostic accuracy but is time-consuming and requires substantial manual input. A novel computer-learning technique called Anatomical Intelligence in ultrasound (AIUS) semiautomatically tracks the annulus and leaflet anatomy for parametric analysis. The aims of this study were to examine whether AIUS could improve accuracy and efficiency in localizing MVP among operators with different levels of experience. METHODS: Two experts and four intermediate-level echocardiographers (nonexperts) retrospectively performed analysis of three-dimensional transesophageal echocardiographic images to generate topographic mitral valve models in 90 patients with degenerative MVP. All echocardiographers performed both AIUS and manual segmentation in sequential weekly sessions. The results were compared with surgical findings. RESULTS: Manual segmentation by nonexperts had significantly lower sensitivity (60% vs 90%, P < .001), specificity (91% vs 97%, P = .001), and accuracy (83% vs 95%, P < .001) compared with experts. AIUS significantly improved the accuracy of nonexperts (from 83% to 89%, P = .003), particularly for lesions involving the A3 (from 81% to 94%, P = .006) and P1 (from 78% to 88%, P = .001) segments, presumably related to anatomic variants of the annulus that made tracking more challenging. AIUS required significantly less time for image analysis by both experts (1.9 ± 0.7 vs 9.9 ± 3.5 min, P < .0001) and nonexperts (5.0 ± 0.5 vs 13 ± 1.5 min, P < .0001), especially for complex lesions. CONCLUSIONS: Anatomic assessment of mitral valve pathology by three-dimensional transesophageal echocardiography is experience dependent. A semiautomated algorithm using AIUS improves accuracy and efficiency in localizing MVP by less experienced operators.

Three-Dimensional Field Optimization Method: Clinical Validation of a Novel Color Doppler Method for Quantifying Mitral Regurgitation.

BACKGROUND: Assessment of mitral regurgitation (MR) severity by echocardiography is important for clinical decision making, but MR severity can be challenging to quantitate accurately and reproducibly. The accuracy of effective regurgitant orifice area (EROA) and regurgitant volume (RVol) calculated using two-dimensional (2D) proximal isovelocity surface area is limited by the geometric assumptions of proximal isovelocity surface area shape, and both variables demonstrate interobserver variability. The aim of this study was to compare a novel automated three-dimensional (3D) echocardiographic method for calculating MR regurgitant flow using standard 2D techniques. METHODS: A sheep model of ischemic MR and patients with MR were prospectively examined. Patients with a range of severity of MR were examined. EROA and RVol were calculated from 3D color Doppler acquisitions using a novel computer-automated algorithm based on the field optimization method to measure EROA and RVol. For an independent comparison group, the 3D field optimization method was compared with 2D methods for grading MR in an experimental ovine model of MR. RESULTS: Fifteen 3D data sets from nine sheep (open-chest transthoracic echocardiographic data sets) and 33 transesophageal data sets from patients with MR were prospectively examined. For sheep data sets, mean 2D EROA was 0.16 ± 0.05 cm2, and mean 2D RVol was 21.84 ± 8.03 mL. Mean 3D EROA was 0.09 ± 0.04 cm2, and mean 3D RVol was 14.40 ± 5.79 cm3. There was good correlation between 2D and 3D EROA (R = 0.70) and RVol (R = 0.80). For patient data sets, mean 2D EROA was 0.35 ± 0.35 cm2, and mean 2D RVol was 58.9 ± 52.9 mL. Mean 3D EROA was 0.34 ± 0.29 cm2, and mean 3D RVol was 54.6 ± 36.5 mL. There was excellent correlation between 2D and 3D EROA (R = 0.94) and RVol (R = 0.84). Bland-Altman analysis revealed greater interobserver variability for 2D RVol measurements compared with 3D RVol using the 3D field optimization method measurements, but variability was statistically significant only for RVol. CONCLUSIONS: Direct automated measurement of proximal isovelocity surface area region for EROA calculation using real-time 3D color Doppler echocardiography is feasible, with a high correlation to current 2D EROA methods but less variability. This novel automated method provides an accurate and highly reproducible method for calculating EROA.

Transthoracic 3D Echocardiographic Left Heart Chamber Quantification Using an Automated Adaptive Analytics Algorithm.

OBJECTIVES: The goal of this study was to test the feasibility and accuracy of an automated algorithm that simultaneously quantifies 3-dimensional (3D) transthoracic echocardiography (TTE)-derived left atrial (LA) and left ventricular (LV) volumes and left ventricular ejection fraction (LVEF). Conventional manual 3D TTE tracings and cardiac magnetic resonance (CMR) images were used as a reference for comparison. BACKGROUND: Cardiac chamber quantification from 3D TTE is superior to 2D TTE measurements. However, integration of 3D quantification into clinical practice has been limited by time-consuming workflow and the need for 3D expertise. A novel automated software was developed that provides LV and LA volumetric quantification from 3D TTE datasets that reflect real-life manual 3-dimensional echocardiography measurements and values comparable to CMR. METHODS: A total of 159 patients were studied in 2 separate protocols. In protocol 1, 94 patients underwent 3D TTE imaging (EPIQ, iE33, X5-1, Philips Healthcare, Andover, Massachusetts) covering the left atrium and left ventricle. LA and LV volumes and LVEF were obtained using the automated software (HeartModel, Philips Healthcare) with and without contour correction, and compared with the averaged manual 3D volumetric measurements from 3 readers. In protocol 2, automated measurements from 65 patients were compared with a CMR reference. The Pearson correlation coefficient, Bland-Altman analysis, and paired Student t tests were used to assess inter-technique agreement. RESULTS: Correlations between the automated and manual 3D TTE measurements were strong (r = 0.87 to 0.96). LVEF was underestimated and automated LV end-diastolic, LV end-systolic, and LA volumes were overestimated compared with manual measurements. Agreement between the automated analysis and CMR was also strong (r = 0.84 to 0.95). Test-retest variability was low. CONCLUSIONS: Automated simultaneous quantification of LA and LV volumes and LVEF is feasible and requires minimal 3D software analysis training. The automated measurements are not only comparable to manual measurements but also to CMR. This technique is highly reproducible and timesaving, and it therefore promises to facilitate the integration of 3D TTE-based left-heart chamber quantification into clinical practice.

Automated quantification of mitral valve anatomy using anatomical intelligence in three-dimensional echocardiography.

BACKGROUND: Quantitative analysis of mitral valve morphology with three-dimensional (3D) transesophageal echocardiography (TEE) provides anatomic information that can assist clinical decision-making. However, routine use of mitral valve quantification has been hindered by tedious workflow and high operator-dependence. The purpose of this paper was to evaluate the feasibility, accuracy and efficiency of a novel computer-learning algorithm using anatomical intelligence in ultrasound (AIUS) to automatically detect and quantitatively assess the mitral valve anatomy. METHODS: A novice operator used AIUS to quantitatively assess mitral valve anatomy on the 3D TEE images of 55 patients (33 with mitral valve prolapse, 11 with functional mitral regurgitation, and 11 normal valves). The results were compared to that of manual mitral valve quantification by an experienced 3D echocardiographer and, in the 24 patients who underwent mitral valve repair, the surgical findings. Time consumption and reproducibility of AIUS were compared to the manual method. RESULTS: AIUS mitral valve quantification was feasible in 52 patients (95%). There were excellent agreements between AIUS and expert manual quantification for all mitral valve anatomic parameters (r=0.85-0.99, p<0.05). AIUS accurately classified surgically defined location of prolapse in 139 of 144 segments analyzed (97%). AIUS improved the intra- [intraclass-correlation coefficient (ICC)=0.91-0.99] and inter-observer (ICC=0.86-0.98) variability of novice users, surpassing the manual approach (intra-observer ICC=0.32-0.95; inter-observer ICC=0.45-0.93), yet requiring significantly less time (144±24s vs. 770±89s, p<0.0001). CONCLUSION: Anatomic intelligence in 3D TEE image can provide accurate, reproducible, and rapid quantification of the mitral valve anatomy.

Dynamic assessment of the changing geometry of the mitral apparatus in 3D could stratify abnormalities in functional mitral regurgitation and potentially guide therapy.

INTRODUCTION: In functional mitral regurgitation (FMR), effective regurgitant orifice area (EROA) displays a dynamic pattern. The impact of dynamic changes of annulus dysfunction and leaflets tenting on phasic EROA was explored with real-time three-dimensional transesophageal echocardiography (RT3D-TEE). METHODS: RT3D-TEE was performed in 52 FMR patients and 30 controls. Mitral annulus dimensions and leaflets tenting were measured throughout systole (TomTec, Germany). Phasic EROA was measured by proximal isovelocity surface area (PISA) method. RESULTS: Mitral annulus had the minimal area and an oval shape with saddle configuration during early systole in controls, which enlarged and became round and flattened towards mid and late systole (P<0.05). In contrast, annulus in FMR was significantly larger, rounder and flatter (P<0.001), which further dilated and became more flattened at late systole (P<0.05 vs control). Leaflet tenting height in FMR decreased in mid systole and remains unchanged towards late systole. The leaflet tenting volume peaked at early and late systole with a mid-systolic trough in both FMR and controls. But tenting volume of patients with FMR was significantly larger than that of controls (all P<0.001 vs control in whole systole). Further analysis demonstrated that early tenting volume (ß value=0.053, P<0.05) was a predictor of early EROA, whereas late tenting volume (ß value=0.031, P<0.05) and late annular displacement velocity were predictors of late EROA. CONCLUSIONS: The early and late peak EROAs of FMR was primarily contributed by tenting volume at early systole and late systole respectively. These findings would be of value to consider in interventions aimed at reducing the severity of FMR.

A new definition for an old entity: improved definition of mitral valve prolapse using three-dimensional echocardiography and color-coded parametric models.

BACKGROUND: Differentiating between mitral valve (MV) prolapse (MVP) and MV billowing (MVB) on two-dimensional echocardiography is challenging. The aim of this study was to test the hypothesis that color-coded models of maximal leaflet displacement from the annular plane into the atrium derived from three-dimensional transesophageal echocardiography would allow discrimination between these lesions. METHODS: Three-dimensional transesophageal echocardiographic imaging of the MV was performed in 50 patients with (n = 38) and without (n = 12) degenerative MV disease. Definitive diagnosis of MVP versus MVB was made using inspection of dynamic three-dimensional renderings and multiple two-dimensional cut planes extracted from three-dimensional data sets. This was used as a reference standard to test an alternative approach, wherein the color-coded parametric models were inspected for integrity of the coaptation line and location of the maximally displaced portion of the leaflet. Diagnostic interpretations of these models by two independent readers were compared with the reference standard. RESULTS: In all cases of MVP, the color-coded models depicted loss of integrity of the coaptation line and maximal leaflet displacement extending to the coaptation line. MVB was depicted by preserved leaflet apposition with maximal displacement away from the coaptation line. Interpretation of the 50 color-coded models by novice readers took 5 to 10 min and resulted in good agreement with the reference technique (κ = 0.81 and κ = 0.73 for the two readers). CONCLUSIONS: Three-dimensional color-coded models provide a static display of MV leaflet displacement, allowing differentiation between MVP and MVB, without the need to inspect multiple planes and while taking into account the saddle shape of the mitral annulus.

Quantitative analysis of mitral valve morphology in mitral valve prolapse with real-time 3-dimensional echocardiography: importance of annular saddle shape in the pathogenesis of mitral regurgitation.

BACKGROUND: Few data exist on the relation of the 3-dimensional morphology of mitral valve and degree of mitral regurgitation (MR) in mitral valve prolapse. METHODS AND RESULTS: Real-time 3-dimensional transesophageal echocardiography of the mitral valve was acquired in 112 subjects, including 36 patients with mitral valve prolapse and significant MR (≥3+; MR+ group), 32 patients with mitral valve prolapse but no or mild MR (≤2+; MR- group), 12 patients with significant MR resulting from nonprolapse pathologies (nonprolapse group), and 32 control subjects. The 3-dimensional geometry of mitral valve apparatus was measured with dedicated quantification software. Compared with the normal and MR- groups, the MR+ group had more dilated mitral annulus (P<0.0001), a reduced annular height to commissural width ratio (AHCWR) (P<0.0001) indicating flattening of annular saddle shape, redundant leaflet surfaces (P<0.0001), greater leaflet billow volume (P<0.0001) and billow height (P<0.0001), longer lengths from papillary muscles to coaptation (P<0.0001), and more frequent chordal rupture (P<0.0001). Prevalence of chordal rupture increased progressively with annulus flattening (7% versus 24% versus 42% for AHCWR >20%, 15%-20%, and <15%, respectively; P=0.004). Leaflet billow volume increased exponentially with decreasing AHCWR in patients without chordal rupture (r(2)=0.66, P<0.0001). MR severity correlated strongly with leaflet billow volume (r(2)=0.74, P<0.0001) and inversely with AHCWR (r(2)=0.44, P<0.0001). In contrast, annulus dilatation but not flattening occurred in nonprolapse MR patients. An AHCWR <15% (odds ratio=7.1; P=0.0004) was strongly associated with significant MR in mitral valve prolapse. CONCLUSION: Flattening of the annular saddle shape is associated with progressive leaflet billowing and increased frequencies of chordal rupture and may be important in the pathogenesis of MR in mitral valve prolapse.

Novel method of measuring valvular regurgitation using three-dimensional nonlinear curve fitting of Doppler signals within the flow convergence zone.

Mitral valve regurgitation (MR) is among the most prevalent and significant valve problems in the Western world. Echocardiography plays a significant role in the diagnosis of degenerative valve disease. However, a simple and accurate means of quantifying MR has eluded both the technical and clinical ultrasound communities. Perhaps the best clinically accepted method used today is the 2-D proximal isovelocity surface area (PISA) method. In this study, a new quantification method using 3-D color Doppler ultrasound, called the field optimization method (FOM), is described. For each 3-D color flow volume, this method iterates on a simple fluid dynamics model that, when processed by a model of ultrasound physics, attempts to agree with the observed velocities in a least-squares sense. The output of this model is an estimate of the regurgitant flow and the location of its associated orifice. To validate the new method, in vitro experiments were performed using a pulsatile flow loop and different geometric orifices. Measurements from the FOM and from 2-D PISA were compared with measurements made with a calibrated ultrasonic flow probe. Results show that the new method has a higher correlation to the truth data and has lower inter- and intra-observer variability than the 2-D PISA method.

Myocardial deformation by speckle tracking in severe dilated cardiomyopathy.

BACKGROUND: The high and increasing prevalence of Dilated Cardiomyopathy (DCM) represents a serious public health problem. New technologies are being used aiming at more accurate diagnoses in order to improve therapeutic approach. In this scenario, speckle tracking echocardiography (STE) uses natural myocardial markers to analyze the systolic deformation of the left ventricle (LV). OBJECTIVE: To measure the longitudinal transmural global strain (GS) of the LV through STE in patients with severe DCM, comparing the results with normal individuals and with echocardiographic parameters established for the analysis of LV systolic function, validating the method in this population. METHODS: We studied 71 patients with severe DCM (53 ± 12 years, 72% men) and 20 controls (30 ± 8 years, 45% men). We obtained LV volumes and ejection fraction by two and three-dimensional echocardiography, Doppler parameters, tissue Doppler and GS was obtained by STE. RESULTS: Compared to controls, LV volumes were higher in the DCM group; however, LVEF and peak velocity of E wave were lower in the latter. The myocardial performance index was higher among patients. Myocardial velocities at the tissue Doppler (S', e', a') were significantly lower and E/e' ratio was higher in the DCM group. The GS was decreased in the DCM group (-5.5% ± 2.3%) when compared to controls (-14.0% ± 1.8%). CONCLUSION: In this study, GS was significantly lower in patients with severe DCM, bringing new perspectives for therapeutic approaches in this specific population.

Deformação miocárdica pelo speckle tracking na cardiomiopatia dilatada grave / Myocardial deformation by speckle tracking in severe dilated cardiomyopathy

FUNDAMENTO: A alta e crescente prevalência de Cardiomiopatia Dilatada (CMD) representa sério problema de saúde pública. Novas tecnologias vêm sendo utilizadas objetivando diagnósticos mais sofisticados, que melhorem a abordagem terapêutica. Nesse cenário, o Speckle Tracking (STE) utiliza marcadores miocárdicos naturais para analisar a deformação sistólica do Ventrículo Esquerdo (VE). OBJETIVO: Mensurar o strain transmural longitudinal global (SG) do VE através do STE em pacientes com CMD grave, comparando os resultados com indivíduos normais e com parâmetros ecocardiográficos consagrados para análise da função sistólica do VE, validando o método nessa população. MÉTODOS: Foram estudados 71 pacientes com CMD grave, (53 ± 12a, 72% homens) e 20 controles (30 ± 8a, 45% homens). Foram obtidos os volumes e a FEVE pela ecocardiografia bi e tridimensional, parâmetros do Doppler, Doppler tecidual e o SG pelo STE. RESULTADOS: Comparados ao grupo controle, os volumes do VE foram maiores no grupo CMD; entretanto, a FEVE e velocidade de pico da onda E foram menores neste último. O índice de performance miocárdica foi maior entre os pacientes. As velocidades do miocárdio pelo Doppler tecidual (S', e', a') foram consideravelmente menores e a relação E/e' foi maior no grupo CMD. O SG apresentou-se diminuído no grupo CMD (-5,5% ± 2,3%), em relação aos controles (-14,0% ± 1,8%). CONCLUSÃO: No presente estudo, o SG foi significativamente menor nos pacientes com CMD grave, abrindo novas perspectivas para abordagens terapêuticas nessa população específica.

BACKGROUND: The high and increasing prevalence of Dilated Cardiomyopathy (DCM) represents a serious public health problem. New technologies are being used aiming at more accurate diagnoses in order to improve therapeutic approach. In this scenario, speckle tracking echocardiography (STE) uses natural myocardial markers to analyze the systolic deformation of the left ventricle (LV). OBJECTIVE: To measure the longitudinal transmural global strain (GS) of the LV through STE in patients with severe DCM, comparing the results with normal individuals and with echocardiographic parameters established for the analysis of LV systolic function, validating the method in this population. METHODS: We studied 71 patients with severe DCM (53 ± 12 years, 72% men) and 20 controls (30 ± 8 years, 45% men). We obtained LV volumes and ejection fraction by two and three-dimensional echocardiography, Doppler parameters, tissue Doppler and GS was obtained by STE. RESULTS: Compared to controls, LV volumes were higher in the DCM group; however, LVEF and peak velocity of E wave were lower in the latter. The myocardial performance index was higher among patients. Myocardial velocities at the tissue Doppler (S', e', a') were significantly lower and E/e' ratio was higher in the DCM group. The GS was decreased in the DCM group (-5.5% ± 2.3%) when compared to controls (-14.0% ± 1.8%). CONCLUSION: In this study, GS was significantly lower in patients with severe DCM, bringing new perspectives for therapeutic approaches in this specific population.

Assessment of right ventricular function using echocardiographic speckle tracking of the tricuspid annular motion: comparison with cardiac magnetic resonance.

BACKGROUND: Assessment of right ventricular (RV) function is difficult due to the complex shape of this chamber. Tricuspid annular plane systolic excursion (TAPSE) measured with M-mode echocardiography is frequently used as an index of RV function. However, its accuracy may be limited by ultrasound beam misalignment. We hypothesized that two-dimensional (2D) speckle tracking echocardiography (STE) could provide more accurate estimates of RV function. Accordingly, STE was used to quantify tricuspid annular displacement (TAD), from which RV longitudinal shortening fraction (LSF) was calculated. These STE derived indices were compared side-by-side with M-mode TAPSE measurements against cardiac magnetic resonance (CMR) derived RV ejection fraction (EF). METHODS: Echocardiography (Philips iE33, four-chamber view) and CMR (Siemens, 1.5 T) were performed on the same day in 63 patients with a wide range of RV EF (23-70% by CMR). TAPSE was measured using M-mode echocardiography. TAD and RV LSF were obtained using STE analysis (QLAB CMQ, Philips). TAPSE, TAD and RV LSF values were compared with RV EF obtained from CMR short axis stacks. RESULTS: STE analysis required <15 seconds and was able to track tricuspid annular motion in all patients as verified visually. Correlation between RV EF and TAD (0.61 free-wall, 0.65 septal) was similar to that with M-mode TAPSE (0.63). However, STE-derived RV LSF showed a higher correlation with CMR EF (r = 0.78). CONCLUSION: RV LSF measurement by STE is fast and easy to obtain and provides more accurate evaluation of RV EF than the traditional M-mode TAPSE technique, when compared to CMR reference. (Echocardiography 2012;29:19-24).

Geometric assessment of regional left ventricular remodeling by three-dimensional echocardiographic shape analysis correlates with left ventricular function.

BACKGROUND: Left ventricular (LV) volumes and ejection fraction derived from two-dimensional echocardiography are two measures of adverse LV remodeling, which predict survival in patients with systolic heart failure. However, the geometric assumptions and image foreshortening that can occur with two-dimensional echocardiography reduces measurement accuracy and thus predictive value. By its nature, three-dimensional (3D) echocardiography allows the entire LV shape to be studied, providing a methodology to examine LV remodeling through LV curvature on a global and regional scale. The aim of this study was to correlate changes in global and regional LV shape to LV ejection fraction. METHODS: Full-volume, 3D transthoracic echocardiographic studies of the left ventricle were performed in 106 consecutive patients with either normal left ventricles (n = 59) or cardiomyopathies (n = 47). Customized software (QLAB) was used to extract segmented 3D LV endocardial shells at end-systole and end-diastole and to analyze these shells to determine global and regional LV shape analysis. Independent t tests were used for intergroup comparisons, and linear regression was used to correlate regional shape changes with systolic performance. RESULTS: Derivation and analysis of the 3D LV shells was possible in all patients. Patients with dilated cardiomyopathy had significantly smaller curvature values, indicating rounder global LV shape throughout the cardiac cycle. Regional analysis identified a loss of septal and apical curvatures in these patients. Systolic apical mean curvature was well correlated with LV ejection fraction (r = 0.89). CONCLUSIONS: This is the first study to demonstrate that regional remodeling measured by regional 3D LV curvature correlates well with LV function. As well, this methodology is independent of the geometric assumptions that limit the predictive value of two-dimensional echocardiographic measures of LV remodeling. Overall, this is a novel tool that may have applications in the assessment and prediction of outcomes of different forms of dilated cardiomyopathy.

A three-dimensional insight into the complexity of flow convergence in mitral regurgitation: adjunctive benefit of anatomic regurgitant orifice area.

Mitral effective regurgitant orifice area (EROA) using the flow convergence (FC) method is used to quantify the severity of mitral regurgitation (MR). However, it is challenging and prone to interobserver variability in complex valvular pathology. We hypothesized that real-time three-dimensional (3D) transesophageal echocardiography (RT3D TEE) derived anatomic regurgitant orifice area (AROA) can be a reasonable adjunct, irrespective of valvular geometry. Our goals were to 1) to determine the regurgitant orifice morphology and distance suitable for FC measurement using 3D computational flow dynamics and finite element analysis (FEA), and (2) to measure AROA from RT3D TEE and compare it with 2D FC derived EROA measurements. We studied 61 patients. EROA was calculated from 2D TEE images using the 2D-FC technique, and AROA was obtained from zoomed RT3DE TEE acquisitions using prototype software. 3D computational fluid dynamics by FEA were applied to 3D TEE images to determine the effects of mitral valve (MV) orifice geometry on FC pattern. 3D FEA analysis revealed that a central regurgitant orifice is suitable for FC measurements at an optimal distance from the orifice but complex MV orifice resulting in eccentric jets yielded nonaxisymmetric isovelocity contours close to the orifice where the assumptions underlying FC are problematic. EROA and AROA measurements correlated well (r = 0.81) with a nonsignificant bias. However, in patients with eccentric MR, the bias was larger than in central MR. Intermeasurement variability was higher for the 2D FC technique than for RT3DE-based measurements. With its superior reproducibility, 3D analysis of the AROA is a useful alternative to quantify MR when 2D FC measurements are challenging.

Characterization of degenerative mitral valve disease using morphologic analysis of real-time three-dimensional echocardiographic images: objective insight into complexity and planning of mitral valve repair.

BACKGROUND: Presurgical planning of mitral valve (MV) repair in patients with Barlow disease (BD) and fibroelastic deficiency (FED) is challenging because of the inability to assess accurately the complexity of MV prolapse. We hypothesized that the etiology of degenerative MV disease (DMVD) could be objectively and accurately ascertained using parameters of MV geometry obtained by morphological analysis of real-time 3D echocardiographic (RT3DE) images. METHODS AND RESULTS: Seventy-seven patients underwent transesophageal RT3DE study: 57 patients with DMVD studied intraoperatively (28 BD, 29 FED classified during surgery) and 20 patients with normal MV who were used as control subjects (NL). MVQ software (Philips) was used to measure parameters of annular dimensions and geometry and leaflet surface area, including billowing volume and height. The Student t test and multinomial logistic regression was performed to identify parameters best differentiating DMVD patients from normal as well as FED from BD. Morphological analysis in the DMVD group revealed a progressive increase in multiple parameters from NL to FED to BD, allowing for accurate diagnosis of these entities. The strongest predictors of the presence of DMVD included billowing height and volume. Three-dimensional billowing height with a cutoff value of 1.0 mm differentiated DMVD from NL without overlap, and billowing volume with a cutoff value 1.15 mL differentiated between FED and BD without overlap. CONCLUSIONS: Morphological analysis as a form of decision support in assessing MV billowing revealed significant quantifiable differences between NL, FED, and BD patients, allowing accurate classification of the etiology of MV prolapse and determination of the anticipated complexity of repair.

Rapid estimation of left ventricular function using echocardiographic speckle-tracking of mitral annular displacement.

BACKGROUND: Left ventricular (LV) ejection fraction (EF) by transthoracic two-dimensional echocardiography is time-intensive and highly dependent on image quality. Mitral annular displacement (MAD) qualitatively correlates with EF and can be measured in patients with poor image quality and dropout. The authors hypothesized that speckle-tracking echocardiography (STE)-derived MAD could quantify EF accurately and tested this hypothesis using cardiac magnetic resonance (CMR) as a reference. METHODS: One hundred eighteen patients undergoing clinical transthoracic echocardiography were screened, and 110 whose mitral annuli was sufficiently well-defined irrespective of LV endocardial visualization underwent CMR within 6 days (85 of 110 in 1 day). Reference CMR EF values were obtained using standard methodology. STE was used to track annular motion throughout the cardiac cycle in the apical 2-chamber and 4-chamber views. To establish the relationship between MAD and CMR EF and to obtain a formula to estimate EF from MAD, regression analysis was performed in a study group of 60 patients with a wide range of EFs. This formula was then used in an independent test group of 50 patients by comparing estimated MAD EF against CMR EF values using Pearson's correlation and Bland-Altman analyses. RESULTS: In the study group, STE MAD correlated highly with CMR EF and resulted in a formula relating MAD to EF. In the test group, estimated EF correlated well with CMR EF (4-chamber, R(2) = 0.64; 2-chamber, R(2) = 0.55), with near-zero bias and acceptable limits of agreement. Intraobserver and interobserver variability were between 5.8% and 12.7%. CONCLUSIONS: STE MAD is a clinically useful tool for quick, easy, robust, and accurate estimates of EF irrespective of LV endocardial definition.

Accuracy of measuring mitral annular velocity by 2D speckle tracking imaging.

BACKGROUND: Recent developments in 2D speckle tracking imaging allow not only measurements of regional myocardial strain, but also velocities of the mitral annulus. The aim of this study was to determine the accuracy of speckle tracking derived mitral annulus velocity compared with conventional pulsed wave Doppler measurements. METHODS: 2D speckle tracking was acquired from the apical 4-chamber view (QLab, Speckle SQ, Philips, Andover, MA) in 169 subjects. While using texture tracking, two small regions of interest (ROIs) were placed in the septal (IVS) and lateral corners (LAT) of the mitral annulus. The software automatically tracked the ROIs frame-by-frame, yielding regional mean velocity curves of the mitral annulus throughout the cardiac cycle (synthetic pulsed wave Doppler; SPW). From these curves, peak systolic, early- and late-diastolic velocities of the mitral annulus (S'-SPW, E'-SPW, and A'-SPW) were measured. Peak systolic, early- and late-diastolic velocity in the mitral annulus (S', E', and A') by conventional pulsed wave tissue Doppler tracing were also obtained. RESULTS: Adequate ROI tracking was observed in 150/169 subjects in IVS and 139/169 subjects in LAT of the mitral annulus. All annular velocities derived from SPW were significantly lower than corresponding velocities obtained from conventional method in both IVS and LAT regions of the mitral annulus. However, significant correlation between S' (E', A')-SPW and S' (E', A') was observed. In particular, a good correlation between E'-SPW and E' was noted in both IVS (r=0.89, P<0.001) and LAT (r=0.85, P<0.001) regions of the mitral annulus. If we defined E/E'-SPW in IVS>26 for predicting E/E' in IVS>15, sensitivity, specificity, and accuracy were 83%, 97%, and 94%, respectively. E/E'-SPW in LAT>13 had a 94% sensitivity, 92% specificity, and 93% accuracy for predicting E/E' in LAT>10. CONCLUSIONS: The values of annular velocities by SPW were significantly lower compared to those assessed by traditional tissue velocities. However, new cut-off values of E/E'-SPW for predicting elevated LV filling pressure highly correlated with traditional parameters. 2D speckle tracking imaging provides another strategy for evaluating LV filling pressures.