Real-time 3-dimensional Echocardiography Research Articles

A Real-Time Three-Dimensional Echocardiographic Quantitative Analysis of Left Atrial Function in Left Ventricular Diastolic Dysfunction

The evaluation of left ventricular diastolic function provides important information about hemodynamics and has prognostic implications for various cardiac diseases. In particular, left atrial (LA) volume is an increasingly significant prognostic biomarker for diastolic dysfunction. The aim of this study was to assess left ventricular diastolic function by measuring changes in LA volume using real-time 3-dimensional echocardiography. The 106 subjects were divided into 4 groups (normal, impaired relaxation, pseudonormal, and restrictive) on the basis of diastolic function, as assessed by transmitral flow patterns. LA volume was measured during a heart cycle using real-time 3-dimensional echocardiography. LA stroke volume (maximum LA volume - minimum LA volume) and the LA ejection fraction (LA stroke volume/maximum LA volume x 100) were calculated using Doppler imaging to assess their correlation with other parameters used to evaluate left ventricular diastolic function, including transmitral flow pattern and early diastolic mitral annular velocity (E'). LA volume indexed to body surface area was dilated in subjects with left ventricular diastolic dysfunction, whereas the LA ejection fraction was lower. The maximum LA volume, minimum LA volume, and LA ejection fraction were significantly different between each group, and each was significantly correlated with the ratio of early diastolic transmitral flow velocity (E) to E' (E/E'). The LA ejection fraction correlated best with E/E' (r = -0.68, p <0.0001). In conclusion, cyclic changes in LA volume could be measured using real-time 3-dimensional echocardiography, and measuring LA function with this method may be a viable alternative for the accurate assessment of left ventricular diastolic function.

A methodology for assessing human mitral leaflet curvature using real-time 3-dimensional echocardiography

Using 3-dimensional echocardiography in conjunction with novel geometric modeling and rendering techniques, we have developed a high-resolution, quantitative, 3-dimensional methodology for imaging the human mitral valve. Leaflet and annular geometry are important determinants of mitral valve stress. Repair techniques that optimize valvular geometry will reduce stress and potentially increase repair durability. The development of such procedures will require image-processing methodologies that provide a quantitative description of 3-dimensional valvular geometry. Ten healthy adult subjects underwent mitral valve imaging with real-time 3-dimensional echocardiography. By using specially designed image analysis software, multiple valvular geometric parameters, including 2- and 3-dimensional leaflet curvature, leaflet surface area, annular height, intercommissural width, septolateral annular diameter, and annular area were determined for each subject. Image-rendering techniques that allow for the clear and concise presentation of this detailed information are also presented. Although 3-dimensional annular and leaflet geometry were found to be highly conserved between healthy human subjects in general, substantial intrasubject and intersubject regional geometric heterogeneity was observed in the midposterior leaflet, the region most commonly involved in leaflet flail in subjects with myxomatous disease. The image-processing and graphic-rendering techniques that we have developed can be used to provide a complete description of 3-dimensional mitral valve geometry in human subjects. Widespread application of these techniques to healthy subjects and patients with mitral valve disease will provide insight into the geometric basis of both valvular pathology and repair durability.

Comparison of Left Atrial Volumes and Function by Real-Time Three-Dimensional Echocardiography in Patients Having Catheter Ablation for Atrial Fibrillation With Persistence of Sinus Rhythm Versus Recurrent Atrial Fibrillation Three Months Later

Real-time 3-dimensional echocardiography (RT3DE) can provide a unique combination of accurate left atrial (LA) volume quantification and rapid, automatic assessment of LA function. The aim of the study was to evaluate the changes in LA volumes and function in patients with atrial fibrillation (AF) undergoing radiofrequency catheter ablation (RFCA) using RT3DE; 57 consecutive patients referred for RFCA were studied. Paroxysmal AF was present in 43 patients (75%) and persistent AF in 14 (25%). After a mean follow-up of 7.9 +/- 2.7 months, patients were divided into 2 groups: successful RFCA (SR group) and recurrence of AF (AF group). RT3DE was performed before, within 3 days, and 3 months after RFCA to assess LA volumes (maximum, minimum, and preA) and LA functions (passive, active, and reservoir). A total of 38 patients (67%) had successful RFCA (SR group). Immediately after RFCA, no significant changes in LA volumes and function were observed. After 3 months, a significant reduction in LA volumes (maximum: 26 +/- 8 to 23 +/- 7 ml/m(2), p <0.01) was noted only in the SR group, with a significant improvement in LA active (22 +/- 8% to 33 +/- 9%, p <0.01) and reservoir functions (116 +/- 45% to 152 +/- 54%, p <0.01). Conversely, the AF group showed a trend towards a deterioration of LA volumes and function. In conclusion, in patients who maintain sinus rhythm after RFCA, a significant reverse remodeling and functional improvement of the left atrium is observed using RT3DE.

Assessing Mitral Valve Area and Orifice Geometry in Calcific Mitral Stenosis: A New Solution by Real-Time Three-Dimensional Echocardiography

Planimetry of mitral valve area (MVA) is difficult in calcific mitral stenosis (CaMS) in which limiting orifice is near the annulus, and unlike rheumatic mitral stenosis (RhMS), does not present an area for planimetry at the leaflet tips. Moreover, pressure half time (PHT)-derived MVA (MVA(PHT)) has limitations in patients with CaMS in whom there are coexisting conditions that affect LV chamber compliance. We tested the hypothesis that real-time 3-dimensional echocardiography (RT3D) can guide measurement at the narrowest orifice in CaMS. In 34 patients with CaMS, MVA by RT3D (MVA(RT3D)) was obtained using a color-defined planimetry technique performed "en face" at the smallest annular orifice cross-section (diastolic maximum). MVA(RT3D) and MVA(PHT) were compared with an independent standard: MVA by continuity equation (MVA(CEQ)). In a subgroup of 10 patients with CaMS or RhMS, the 3-dimensional shape of the stenotic mitral valve was examined, guided by color flow mapping. MVA(PHT) overestimated the mitral orifice area compared with MVA(CEQ) (2.01 +/- 0.52 cm(2) vs 1.75 +/- 0.46 cm(2); P = .037), whereas there was no significant difference in MVA(RT3D) and MVA(CEQ) (1.83 +/- 0.52 cm(2) vs 1.75 +/- 0.46 cm(2), respectively, P = .61). MVA(RT3D) had a greater correlation with MVA (CEQ) than MVA(PHT) (R = 0.86 vs 0.59 MVA(RT3D) vs MVA(PHT), respectively). There was better agreement between MVA by RT3D and MVA by continuity equation than MVA by PHT and MVA by continuity equation (difference in MVA: 0.23 +/- 0.15 cm(2) vs 0.43 +/- 0.29 cm(2); P < .0001, MVA(RT3D) - MVA(CEQ) vs MVA(PHT) - MVA(CEQ,) respectively). In CaMS, there was a tubular geometry to the valve shape. In contrast, RhMS had a doming funnel-shaped geometry. RT3D provides an accurate measurement of MVA in CaMS. In contrast with the doming valve shape present in RhMS, the limiting anatomic orifice area occurs at the annulus in CaMS as measured by RT3D and reflects the effective orifice area as present in a tubular valve geometry.

Accuracy and Reproducibility of Quantitation of Left Ventricular Function by Real-Time Three-Dimensional Echocardiography Versus Cardiac Magnetic Resonance

The aim of this study was to investigate the accuracy and reproducibility of the quantification of left ventricular (LV) function by real-time 3-dimensional echocardiography (RT3DE) using current state-of-the-art hardware and software. Compared with cardiac magnetic resonance (CMR), previous generations of hardware and software for RT3DE significantly underestimated LV volumes partly because of inherent factors such as limited spatial and temporal resolution. Also, RT3DE volumes were compared with short-axis CMR data, whereas a combined short-axis and long-axis analysis is known to be superior. Twenty-four subjects (mean age 51 +/- 12 years, 17 men) in sinus rhythm and with good to excellent 2-dimensional image quality underwent RT3DE and CMR within 1 day. The acquisition of RT3DE data was done with current state-of-the-art hardware and software. Two blinded experts performed off-line LV volume analysis. Global LV volumes were determined from semiautomated border detection on the basis of endocardial speckle tracking with biplane projections using QLAB version 6.0. Volumes derived by magnetic resonance imaging were quantified from combined short-axis and long-axis series. The volume-rate on RT3DE was 33 +/- 8 Hz (range 19 to 42). Excellent correlations were found (R2 > or = 0.97) between CMR and RT3DE for global LV end-diastolic volume, LV end-systolic volume, the LV ejection fraction, and LV phase volumes (24 phases/cardiac cycle). Bland-Altman analyses showed mean differences of -7.1 ml, -4.2 ml, 0.2%, and -5.8 ml and 95% limits of agreement of +/-19.7 ml, +/-8.3 ml, +/-6.2%, and +/-15.4 ml for global LV end-diastolic volume, LV end-systolic volume, the LV ejection fraction, and LV phase volumes, respectively. Interobserver variability was 5.2% for global LV end-diastolic volume, 6.4% for LV end-systolic volume, and 7.6% for the LV ejection fraction. In conclusion, in patients with good acoustic windows, RT3DE using state-of-the-art technology provides accurate and reproducible measurements of global LV volumes, LV volume changes over time, and the LV ejection fraction.

Tomographic Left Ventricular Volumetric Emptying Analysis by Real-Time 3-Dimensional Echocardiography

Background— The sequence of left ventricular (LV) systolic emptying is not completely understood. Using real-time 3-dimensional echocardiography, we investigated this sequence and LV synchronicity in physiological and pathological conditions. Methods and Results— The study population consisted of 116 healthy volunteers, 20 top-level athletes, 35 patients with LV dysfunction, and 84 patients with LV dysfunction and left bundle-branch block (LBBB). We subdivided the LV into 16 volumetric segments for regional analysis and into apical, middle, and basal regions to calculate the mean of end-systolic times and the time to minimum systolic volume of each region. In healthy volunteers and in top-level athletes, the emptying systolic times increased smoothly from apex to base. These differences determined an apex-to-base time gradient in the LV emptying sequence. In patients with LV dysfunction and without LBBB, this gradient was maintained with a relatively higher LV dyssynchrony. However, in patients with LV dysfunction and LBBB, there was no clear sequence in LV emptying volumes, and this group had the highest LV dyssynchrony. Conclusions— Real-time 3-dimensional echocardiography tomographic slicing of the LV enables accurate analysis of LV emptying in physiological conditions and in conditions of LV dysfunction with and without electrical dyssynchrony. Progressive dilation of LV produces deterioration in LV synchronicity. However, it is the presence of LV dysfunction in combination with LBBB that determines the loss of the apex-to-base time gradient in LV emptying.

Real-Time 3-Dimensional Transesophageal Echocardiography During Left Atrial Radiofrequency Catheter Ablation for Atrial Fibrillation

Left atrial radiofrequency catheter ablation has been recognized as an important treatment option for drug-refractory symptomatic atrial fibrillation.1 Recent consensus on technique favors catheter ablation directed to the left atrium near the pulmonary vein (PV) ostium to achieve PV isolation.2 However, ablation in the region of the ligament of Marshall (LOM) to achieve electrical isolation of the left PVs can be difficult because of variable catheter stability. The superior extent of the LOM protrudes into the body of the left atrium between the anterior region of the left PV antrum and the left atrial appendage (Figure 1A). Inadvertent misdirection of ablative lesions anterior to the LOM in the region of the left atrial appendage increases the risk of cardiac perforation and does not contribute to successful PV isolation, and misdirection of ablative lesions posteriorly into the left PV or posterior left PV antrum can result in PV stenosis or fatal esophageal injury,2 respectively. Thus, circumferential isolation of the left PVs via precise delivery of ablative lesions outside the PV ostium, including the region of the LOM ridge, would be expected to enhance procedural safety and efficacy.3 More specifically, …

Real-time three-dimensional echocardiography as a novel approach to assess left ventricular and left atrium reverse remodeling and to predict response to cardiac resynchronization therapy

Real-time 3-dimensional echocardiography (RT3DE) is a novel promising technique for the assessment of left ventricular (LV) dyssynchrony. This study sought to explore the value of RT3DE to assess LV and left atrium (LA) reverse remodeling and to predict response to cardiac resynchronization therapy (CRT). A total of 57 consecutive heart failure patients scheduled for CRT were included, and RT3DE was performed before and 6 months after implantation. LV dyssynchrony was defined as the standard deviation of the time to reach the minimum systolic volume for 16 LV segments, expressed in percentage of cardiac cycle (systolic dyssynchrony index, SDI). Patients were divided into responders or nonresponders, based on a reduction >or=15% in LV end-systolic volume after CRT. Six patients (10%) were excluded from further analysis because of suboptimal images. Of the remaining 51 patients, 34 (67%) were classified as responders. Baseline characteristics were similar between responders and nonresponders, except for the SDI, which was larger in responders (9.7% +/- 3.6% versus 5.1% +/- 1.8%, P <.0001). ROC curve analysis revealed that a cutoff value for SDI of 6.4% yielded a sensitivity of 88% with a specificity of 85% to predict response to CRT. In responders, RT3DE also showed beneficial effects of CRT on LA: (1) significant LA reverse remodeling; (2) significant improvement in LA total emptying fraction and in LA conduit and reservoir function. RT3DE allows assessment of changes in LV and LA volumes and function after CRT, and it is highly predictive for response to CRT.

Transthoracic real-time three-dimensional echocardiography offers additional value in the assessment of mitral valve morphology and area following mitral valve repair

The accurate postoperative assessment of mitral valve repair is important not only to document operative outcome, but also to confirm the functional morphology of the repaired valve. We assessed 25 consecutive patients following mitral valve repair with transthoracic real-time 3-dimensional echocardiography (RT3DE) and 2-dimensional echocardiography (2DE). We compared the adequacy of the visualization of the mitral valve Carpentier segments, the site of the repair, and the accuracy of planimetry by RT3DE and 2DE in estimating the postoperative mitral valve area (MVA), compared to the Doppler-derived pressure half-time (PHT) value. Inter-observer variability and feasibility were also assessed for RT3DE. Adequate visualization of the mitral valve segments was more frequently obtained by 3DE imaging (163/170 by 3DE vs. 121/170 by 2DE, P < 0.001). In particular, the mitral valve commissures were more clearly identified with 3DE. 3DE also was significantly better at correctly identifying the site of the repaired segment (26/30 by 3DE vs. 19/30 by 2DE, P < 0.05). The difference in MVA (mean difference +/- SD) determined by 3DE planimetry, when compared to PHT was -0.21 +/- 0.46 cm(2) and -0.44 +/- 0.95 cm(2) for 2DE (P = 0.014). Planimetry by 3DE more closely correlated with the MVA calculated by PHT than 2DE planimetry (r = 0.89 for 3DE vs. r = 0.6 for 2DE). Imaging with RT3DE was both feasible, with a mean acquisition time of 4.02 +/- 1.68 min, and data analysis time of 15.82 +/- 3.9 min, and reproducible, with good inter-observer variability for segment scoring with 3DE (kappa = 0.79) and mean inter-observer difference in assessing MVA by 3DE planimetry of 0.18 +/- 0.12 cm(2) (P = NS). This study suggests that RT3DE offers additional morphological postoperative data of repaired mitral valves, and increases the accuracy of MVA estimation by planimetry. It is both feasible in a busy echocardiography department and reproducible.

Real-Time 3-Dimensional Transesophageal Echocardiography

With the increase in cardiac transcatheter interventions, multiplane 2-dimensional transesophageal echocardiography (TEE) and intracardiac echocardiography have emerged as guiding tools, but they have potential limitations in clarifying the spatial relationship of the catheters relative to surrounding structures.1 Recently, the use of real-time 3-dimensional (3D) transthoracic echocardiography has been reported in Amplatzer closure device procedures2 and in endomyocardial diagnostic and therapeutic procedures.3 The real-time 3D technology now has been merged with TEE to provide superior high resolution for the real-time volume image from the …

Direct Assessment of Size and Shape of Noncircular Vena Contracta Area in Functional Versus Organic Mitral Regurgitation Using Real-Time Three-Dimensional Echocardiography

Vena contracta width (VCW) as an estimate of effective regurgitant orifice area (EROA) is an accepted parameter of mitral regurgitation (MR) severity. However, uncertainty exists in cases in which VCW at the same time appears narrow in 4-chamber (4CH) view and broad in 2-chamber (2CH) view as common in functional MR with noncircular or slit-like regurgitant orifices. We therefore hypothesized that new real-time 3-dimensional color Doppler echocardiography (RT3DE) can be used for direct assessment of the size and shape of vena contracta area (VCA) in an en face view and to determine the potential error of conventional VCW measurement on estimation of EROA. RT3DE was performed in 57 patients with relevant MR of different etiologies. Manual tracing of VCA in a cross-sectional plane through the vena contracta was compared with VCW in 4CH and 2CH views. As a comparative approach to VCA-3D, EROA was calculated using the hemispheric and hemielliptic proximal isovelocity surface (PISA) area method. Direct measurement of VCA-3D was feasible in all patients within 2.6 +/- 0.7 minutes. RT3DE revealed significant asymmetry of VCA in functional compared with organic MR (P < .001). Among all patients, VCW-4CH and VCW-2CH correlated only moderately to VCA-3D (r =.77; r =.80). Mean VCW correlated and agreed best with VCA-3D (r =.90). VCA-3D correlated and agreed well with EROA by hemielliptic PISA (r = .96, mean error: -0.09 +/- 0.14 cm(2)) compared with significant underestimation of hemispheric PISA in noncircular lesions. Direct assessment of VCA using RT3DE revealed significant asymmetry of VCA in functional MR compared with organic MR, resulting in poor estimation of EROA by single VCW measurements.

Real-Time Three-Dimensional Transesophageal Echocardiographic Imaging of Endomyocardial Fibrosis

THE FIRST CASE OF real-time 3-dimensional (3D) transesophageal echocardiography (TEE) imaging of an intracardiac mass is reported. Histologic examination later confirmed the diagnosis of endomyocardial fibrosis (EMF). The utilization of real-time 3D imaging to improve the understanding of the precise anatomic location and the dynamic relationship between this rare intracardiac mass and the surrounding anatomic structures during the cardiac cycle is described. Additionally, a brief review of EMF is provided.

Fate of Left Atrial Function as Determined by Real-Time Three-Dimensional Echocardiography Study After Radiofrequency Catheter Ablation for the Treatment of Atrial Fibrillation

Radiofrequency catheter ablation has been demonstrated to be effective in the treatment of patients with atrial fibrillation. However, its impact on left atrial (LA) function has not been widely studied. The purpose of the present study was to evaluate the impact of radiofrequency catheter ablation on LA function in patients with atrial fibrillation. Thirty-eight patients with symptomatic drug-refractory atrial fibrillation were treated with circumferential pulmonary vein ablation (CPVA). LA volumes and function were assessed with real-time 3-dimensional echocardiography before and 6 months after the procedure. The effectiveness of CPVA was evaluated at 6-month follow-up. Recurrence of the arrhythmia was defined as any documented (clinically or on 24-hour Holter electrocardiography) atrial tachyarrhythmia lasting>30 seconds after the first 12 weeks after the procedure. CPVA induced a reduction of maximum LA volume (from 55+/-15 to 48+/-16 ml, p<0.001), without impairment in LA function, measured as the active emptying percentage of total volume (32+/-29% vs 39+/-33%, p=NS). At follow-up, 21 patients (61.8%) had no recurrences. Maximum LA volumes were significantly larger in patients who presented with recurrences compared with those who did not (64+/-18 vs 50+/-11 ml, p=0.01). In conclusion, CPVA induces a reduction in LA volume without a deleterious impact on function, and, of importance, real-time 3-dimensional echocardiography is a useful noninvasive imaging tool to follow up LA remodeling and function in these patients.

Diagnostic Value of Left Ventricular Outflow Area in Patients with Hypertrophic Cardiomyopathy: A Real-Time Three-Dimensional Echocardiographic Study

Earlier studies demonstrated the ability of real-time 3-dimensional (3D) echocardiography (3DE) to measure left ventricular outflow tract (LVOT) area (A(LVOT)) in patients with hypertrophic cardiomyopathy (HCM). However, its clinical value is unknown. We sought to investigate the feasibility and accuracy of real-time 3DE-derived A(LVOT) to diagnose significant LVOT obstruction in a large number of patients with HCM. A total of 162 patients with HCM had 3DE by using a volumetric system. The smallest A(LVOT) during systole was determined by moving a 2-dimensional plane in 3D space. The pressure gradient across LVOT was assessed by continuous wave Doppler method. Provocation was performed in patients without significant LVOT obstruction (pressure gradient across LVOT < 50 mm Hg) at rest. Twenty (12%) patients with poor image quality of 3DE were excluded; 16 (28%) patients with a volumetric system, but only 4 (4%) patients with commercial equipment (P < .001). In the remaining 142 patients, A(LVOT) inversely correlated with pressure gradient across LVOT both at rest (r = 0.82, P < .001) and after provocation (r = 0.60, P < .001). The value of A(LVOT) less than 0.85 cm(2) and less than 2.0 cm(2) predicted resting and provokable LVOT obstruction with sensitivity of 87% and 81%, and specificity of 77% and 90%, respectively. Real-time 3DE measurement of A(LVOT) was successful in diagnosing and quantifying LVOT obstruction at rest and after provocation in a large number of patients with HCM.

Three-Dimensional Echocardiography for Evaluating Left Ventricular Function in Patients With ST Elevation Myocardial Infarction: A Pilot Study

To the Editor: Two-dimensional echocardiography has been used for decades to evaluate left ventricular systolic function. Live 3-dimensional echocardiography provides accurate measurements of left ventricular volumes and ejection fraction (EF) with fewer geometric assumptions.1,2 The aims of this pilot study were to quantify left ventricular volumes and EF by 3-dimensional echocardiography and evaluate the reproducibility of these measurements compared with 2-dimensional echocardiography. We recruited patients admitted to the hospital with a diagnosis of ST elevation myocardial infarction and referred for clinically indicated transthoracic echocardiography. Bedside echocardiographic images were obtained by the same experienced echocardiographer (A.M.A.-O.) using iE33 equipment (Philips Medical Systems, Bothell, WA) and second harmonic mode. Q lab-Advanced Quantification software (Philips Medical Systems) was used for both 2- and 3-dimensional tracings. For 2-dimensional mode, the left ventricular volumes and EF were calculated using the biplane Simpson method.3 For the 3-dimensional mode, the left ventricular volumes and EF were calculated by the software after 2 independent experienced cardiologists (A.M.A.-O. and F.B.) manually traced the endocardial border. For each variable, 3 tracings were obtained and averaged for each imaging modality. From October 2006 to April 2007, we recruited 30 patients (mean ± SD age, 61±15 years; 77% men; body mass index, 30.0±4.9 kg/m2). Images were adequate for analysis by both 2-and 3-dimensional methods in 24 of the 30 patients; feasibility was 80%. By 2-dimensional echocardiography, end-diastolic volume was 85±26 mL; end-systolic volume, 42±17 mL; and EF, 54±7.6%. By 3-dimensional echocardiography, end-diastolic volume was 88±26 mL; end-systolic volume, 40±15 mL; and EF, 55±8%. The correlation between the 2 echocardiographic techniques was high for the evaluation of EF (r=0.90; P<.001), left ventricular end-diastolic volume (r=0.93; P<.001), and left ventricular end-systolic volume (r=0.92; P<.001). Inter-observer and intraobserver correlations for end-systolic volume and EF were similar for the 2 imaging techniques. However, for end-diastolic volume, interobserver correlations were better for 3-dimensional echocardiography, and intraobserver correlation also tended to be better for 3-dimensional echocardiography (Table). TABLE Pearson Correlation Coefficients Comparing 3-D and 2-D Echocardiography by 2 Independent Observers and Intraobserver Intraclass Correlation Coefficients for 24 Patientsa Echocardiography equipment is portable, and thus images can be obtained at bedside with minimal discomfort or risk to the patient. In this pilot study, the bedside use of real time 3-dimensional echocardiography had adequate feasibility. Most of the study patients had a high body mass index and were older than 60 years, features associated with reduced imaging quality.4 The reproducibility for 3-dimensional echocardiography was slightly superior to that for 2-dimensional echocardiography for measurement of end-diastolic volume. In previous studies that compared 3-dimensional echocardiography to cardiac magnetic resonance imaging, assessment of EF was similar by both techniques.1,2 In another study of patients with prior myocardial infarction that compared both 3-dimensional echocardiography and single photon emission computed tomography to the reference cardiac magnetic resonance imaging, 3-dimensional echocardiography was more accurate than single photon emission computed tomography with less underestimation of volumes.5 Future advances in the technology for live 3-dimensional echocardiography and use of contrast echocardiography should improve the feasibility of this technique for evaluating left ventricular volumes and EF.

Accuracy of real-time 3-dimensional echocardiography in the assessment of mitral prolapse. Is transesophageal echocardiography still mandatory?

Segmental analysis in mitral prolapse is important to decide the chances of valvular repair. Multiplane transesophageal echocardiography (TEE) is the only echocardiographic tool validated for this aim hitherto. The aim of the study was to assess if segmental analysis can be performed with transthoracic real-time 3-dimensional (3D) echocardiography as accurately as with TEE, hence representing a valid alternative to TEE. Forty-one consecutive patients diagnosed with mitral prolapse underwent TEE and a complete 3D echocardiography study, including parasternal and apical real-time; apical full-volume; and 3D color full-volume. Investigators performing TEE were blinded to the 3D results. Three-dimensional echocardiogram was feasible in 40 to 41 patients (97.7%). Ages ranged from 15 to 92 years, and all possible anatomical patterns of prolapse were represented. Thirty-seven patients (90.2%) had mitral regurgitation of any degree. The level of agreement was k = 0.93 (P < or = .0001), sensitivity of 96.7%, specificity of 96.7%, likelihood ratio for a positive result of 29.0%, and likelihood ratio for a negative result of 0.03%. Four false positives were found, corresponding to scallops A2 (1), A3 (2), and P3 (1). Four false negatives were found, corresponding to scallops A1 (2) and P1 (2). Sensitivity and specificity in the scallop P2 were 100%. Segmental analysis in mitral prolapse can be performed with transthoracic real-time 3D echocardiography as accurately as with TEE. False negatives tend to appear around the anterolateral commissure, whereas false positives tend to appear around the posteromedial commissure. Highest accuracy was reached in central scallops.

Echo optimization of cardiac resynchronization therapy

Echocardiography has a prominent role in the era of cardiac resynchronization therapy (CRT) by virtue of its noninvasive nature with high feasibility and reproducibility. More importantly, it permits serial assessment for optimization of the therapy before and after device implantation [1]. First, echocardiography can optimize selection of CRT candidates by baseline evaluation of left ventricular (LV) dyssynchrony and myocardial contractility reserve. Second, it may be used to guide the LV lead position in order to avoid those areas with extensive scar. Finally, it is important in optimization of device programming, including atrioventricular (AV) and interventricular (VV) intervals. Although the clinical and echocardiographic benefits of CRT have been well demonstrated, about one-third of patients did not respond to the therapy, in whom the lack of systolic dyssynchrony before device implantation is mainly attributable [1,2]. Various advanced echo techniques, such as tissue Doppler imaging (TDI) and its postprocessing modalities, real-time 3-dimensional echocardiography (RT3DE) and 2-dimensional speckle tracking, have been proved to be able to detect LV dyssynchrony and predict acute or chronic favorable responses after CRT [3−5]. In addition, a certain myocardial reserve might also be necessary, as reflected by a positive result in stress echo or a preserved circumferential strain at baseline [6,7]. With rapidly evolving new technologies, more accurate identification of responders to CRT by echocardiography would be expected so as to reduce the number of nonresponders and improve the cost effectiveness of the therapy. Despite the presence of pre-implant LV dyssynchrony, recent data from MRI have demonstrated that patients with scar tissue in the posterolateral LV segments, where the LV lead is usually located, failed to show clinical and echocardiographic responses after CRT [8]. It suggests the importance of deploying the LV lead away from scar areas. However, it is unclear whether the assessment of scar region by use of echo methods would have predictive value, though the extent of scar tissue by contrast echo was shown to be inversely related to CRT responses [9]. It also needs more information whether discordance between the site of latest activation and the position of LV lead would give rise to a lesser degree of improvement after CRT, though being suggestive in observational and registry studies. Improvement of AV dyssynchrony is one of the mechanisms of benefit from CRT, which is particularly helpful in those patients with 1st AV block where diastolic filling time will be in further jeopardy [2]. Optimization of AV interval is in attempt to ensure AV synchrony and near 100% ventricular pacing in individual patient, which results in decrease in pre-systolic time, abolishment of diastolic mitral regurgitation, increase in LV filling time and gain in cardiac output. The two commonly employed methods by Doppler echocardiography are based on the principles of optimal LV diastolic filling or maximal cardiac output. Usually, AV interval optimization is performed shortly after the device implantation, ie. at the pre-discharge period. However, re-optimization of AV interval at intermediate (e.g. 3 months) and long-term (e.g.12−18 months) follow up may be necessary to further improvement in cardiac performance.[10] VV Optimization may further reduce ventricular dyssynchrony and hence improve systolic function. Currently, optimization of VV interval is commonly based on the reiterative cardiac output method, which is very time-consuming. However, the benefit of VV timing over conventional simultaneous biventricular pacing needs to be confirmed by large, prospective, randomized studies [11].

リアルタイム三次元経食道心エコーで観察した冠静脈洞型心房中隔欠損

リアルタイム三次元経食道心エコーで観察した冠静脈洞型心房中隔欠損

Real-time 3-dimensional echocardiography – can there be one more dimension?

There is an essential importance of non-invasive imaging methods for evaluation of cardiac patients. Theoretically, the heart can be examined exactly, if due to its nature assessed in three dimensions (3D) concerning the heart cycle. In recent studies it has been confirmed that the second-generation real-time three-dimensional echocardiography offers optimal opportunity for three-dimensional evaluation of cardiac structures. Real-time three-dimensional echocardiography is a valuable tool for exact evaluation of ventricular and atrial volumes and ventricular masses. Valves and congenital abnormalities can be analysed 'en-face' with this new methodology. The usefulness of this method with stress protocols has been confirmed. The aim of the present review is to demonstrate advantages of this new promising method showing recent technological limitations as well.

Left Atrial Volume Measured by Real-Time 3-Dimensional Echocardiography Predicts Clinical Outcomes in Patients with Severe Left Ventricular Dysfunction and in Sinus Rhythm

The clinical value of real-time 3-dimensional echocardiography assessments of left atrial volume in patients with left ventricular dysfunction has not been determined. Real-time 3-dimensional echocardiography and 2-dimensional Doppler echocardiography were performed on the same day in 108 patients with severe left ventricular dysfunction and in sinus rhythm. End-systolic left atrial volumes were measured using real-time 3-dimensional echocardiography images (LAV-3D) and end-systolic left atrial volumes were calculated by the biplane area-length formula using 2-dimensional echocardiography (LAV-2D). Patients were observed clinically over 10 +/- 7 months. LAV-2D showed excellent correlation with LAV-3D (r = 0.88, P < .001), but the former was significantly smaller than the latter (-12 +/- 21 mL, P < .001). During follow-up, 31 patients (29%) showed clinical events, including 3 cardiac deaths and 28 hospitalizations as a result of heart failure. Patients with clinical events had larger initial LAV-3D (P < .05) and LAV-2D (P = .05), higher transmitral E velocity, higher E/E' ratio, more severe mitral and tricuspid regurgitation, and higher maximal velocity of tricuspid regurgitation than the 77 patients without events. LAV-3D (P < .001) and age (P < .05) were independent predictors of cardiac events by Cox proportional hazard model, whereas LAV-2D was negatively involved. Patients with initial LAV-3D less than 100 mL had a significantly higher 1-year event-free survival than those with LAV-3D greater than or equal to 100 mL (80 +/- 7 vs 48 +/- 10%, P < .001). LAV-3D is a major predictor of clinical events in patients with severe left ventricular dysfunction and in sinus rhythm. The clinical value of LAV-3D seems to be superior to that of LAV-2D.