Three-dimensional Transesophageal Echocardiographic Imaging Research Articles

Variations in Mitral Valve Leaflet and Scallop Anatomy on Three-Dimensional Transesophageal Echocardiography

Textbook depictions of the mitral valve (MV) often illustrate it as composed of a single nonscalloped anterior leaflet, with the posterior leaflet having three symmetric and evenly spaced scallops. However, common variations in this anatomy have been noted in autopsy series for decades. Improved cardiac imaging with three-dimensional transesophageal echocardiography (TEE) now affords the ability to detect variations in scallop anatomy invivo. The aims of this study were to catalog variations in mitral anatomy and to examine for association with mitral regurgitation in patients referred for clinical three-dimensional TEE. Three-dimensional transesophageal echocardiographic images of the MV from 107 subjects were reviewed for MV variations. Three-dimensional analysis software was used to characterize mitral leaflet anatomy and assess the relative sizes of posterior leaflet scallops. Variations from the classic MV configuration were seen in 58.9%. Symmetric variations in the posterior leaflet (dominant P2 scallop, accessory P2 scallop, absent P2 scallop, and dichotomous P2 scallop) were seen in 33.6% of the study group. Asymmetric variants in the posterior leaflet (fused P1 and P2, fused P2 and P3, commissural scallop, accessory scallops, dichotomous P1 or P3, and dominant P2 or P3) were seen in 24.3%. Indentations or folds in the anterior leaflet were noted in 5.6%. Leaflet variations were not associated with patient demographics, indication for TEE, mitral regurgitation, mitral annular dimensions, or Carpentier class. Mitral leaflet morphologic variants were well characterized using three-dimensional TEE. Variants are common and were present with a frequency consistent with autopsy series. Mitral scallop variations were not associated with mitral regurgitation.

Risk for Increased Mean Diastolic Gradient after Transcatheter Edge-to-Edge Mitral Valve Repair: A Quantitative Three-Dimensional Transesophageal Echocardiographic Analysis

Iatrogenic mitral stenosis is a known limitation of transcatheter edge-to-edge mitral valve repair (TMVr), but determinants of increased postprocedural mean diastolic gradient (MG) are not well defined. The aim of this study was to determine correlates of increased post-TMVr MG or aborted clip implantation due to increased MG. Procedural three-dimensional transesophageal echocardiographic (TEE) data sets of 112 patients who underwent TMVr were retrospectively analyzed. Three-dimensional TEE mitral valve area (MVA) planimetry and mitral annular calcification (MAC) were quantified using multiplanar reconstruction. When MAC extension into the mitral leaflets was present, MAC with leaflet calcification (MAC-LC) length was recorded as the maximum distance from the mitral annulus to the most distal leaflet calcification. Increased MG after TMVr, measured on intraprocedural TEE imaging, was defined as ≥5mm Hg or aborted clip implantation due to increased MG. Baseline MVA was 5.9±1.7cm2, baseline MG was 2.1±1.2mm Hg, and MAC-LC length was 4.0±4.5mm. Thirty-two patients (29%) had increased post-TMVr MG. Risk for increased post-TMVr MG was 86%, 28%, and 14% in patients with baseline MVA < 4.0, 4.0 to 6.0, and >6.0cm2, respectively (P<.001). In patients with baseline MVA 4.0 to 6.0cm2, concurrent baseline MG≥4mm Hg or MAC-LC ≥ 6mm was associated with higher risk for increased post-TMVr MG (53% vs 12%, P=.002). In patients with baseline MVA < 4.0 and >6.0cm2, the risk for increased post-TMVr MG was similar in the presence or absence of baseline MG≥4mm Hg or MAC-LC ≥ 6mm(P>.05 for both). Patients with baseline three-dimensional TEE MVA<4.0cm2 are at high risk for increased post-TMVr MG. Additionally, patients with borderline MVA (4.0-6.0cm2) and concurrent MAC-LC length≥6mm or baseline MG≥4mm Hg are at moderate risk for increased MG after TMVr.

Utility of Three-Dimensional Transesophageal Echocardiography for Mitral Annular Sizing in Transcatheter Mitral Valve Replacement Procedures: A Cardiac Computed Tomographic Comparative Study

Three-dimensional (3D) transesophageal echocardiographic (TEE) imaging is frequently used as an initial screening tool in the evaluation of patients who are candidates for transcatheter mitral valve replacement (TMVR). However, little is known about the imaging correlation with the gold standard, computed tomographic (CT) imaging. The aims of this study were to test the quantitative differences between these two modalities and to determine the best 3D TEE parameters for TMVR screening. Fifty-seven patients referred to the heart valve clinic for TMVR with prostheses specifically designed for the mitral valve were included. Mitral annular (MA) analyses were performed using commercially available software on 3D TEE and CT imaging. Three-dimensional TEE imaging was feasible in 52 patients (91%). Although 3D TEE measurements were slightly lower than those obtained on CT imaging, measurements of both projected MA area and perimeter showed excellent correlations, with small differences between the two modalities (r=0.88 and r=0.92, respectively, P<.0001). Correlations were significant but lower for MA diameters (r=0.68-0.72, P<.0001) and mitroaortic angle (r=0.53, P=.0001). Receiver operating characteristic curve analyses showed that 3D TEE imaging had a good ability to predict TMVR screening success, defined by constructors on the basis of CT measurements, with ranges of 12.9 to 15cm2 for MA area (area under the curve [AUC]=0.88-0.91, P<.0001), 128 to 139mm for MA perimeter (AUC=0.85-0.91, P<.0001), 35 to 39mm for anteroposterior diameter (AUC=0.79-0.84, P<.0001), and 37 to 42mm for posteromedial-anterolateral diameter (AUC=0.81-0.89, P<.0001). Three-dimensional TEE measurements of MA dimensions display strong correlations with CT measurements in patients undergoing TMVR screening. Three-dimensional TEE imaging should be proposed as a reasonable alternative to CT imaging in this vulnerable population.

Which Cardiac Structure Lies Nearby? Revisiting Two-Dimensional Cross-Sectional Anatomy

Two-dimensional (2D) transthoracic echocardiography is one of the most used diagnostic tools in clinical cardiology. Similarly, 2D transesophageal echocardiography is considered an indispensable tool for cardiologists and cardiac anesthesiologists worldwide. However, because of their tomographic nature, both techniques display only thin cut planes of a given area of the heart, which are far from representing the "anatomic reality." It is widely accepted that experienced echocardiographers are able to reconstruct mentally a three-dimensional image of any cardiac structure on the basis of their interpretation of multiple tomographic slices. However, this may not be the case with less experienced echocardiographers. In particular, the authors noticed that less experienced echocardiographers are almost totally unaware of which structures lie "nearby" a given 2D tomographic plane, that is, what is adjacent in the elevation plane. In this article, the authors report the use of three-dimensional transesophageal echocardiographic images to discover which structures are located nearby (i.e., "behind" and "in front") the corresponding 2D cross-sections. The authors believe that this novel use of three-dimensional echocardiography is a unique aid to disclose what cannot be seen in a given 2D cross-section, thereby expanding our understanding of 2D echocardiographic anatomy. This may be an effective method to encourage all to "think" in three dimensions, even when they use 2D echocardiography.

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

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. 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. 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%). 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.

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

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. 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. 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±3.5min, P<.0001) and nonexperts (5.0±0.5 vs 13±1.5min, P<.0001), especially for complex lesions. 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.

Visualization and Measurement of Mitral Valve Chordae Tendineae Using Three-Dimensional Transesophageal Echocardiography from the Transgastric Approach

The evaluation of the submitral apparatus is challenging from the conventional transesophageal approach. The aim of this study was to test the feasibility of using three-dimensional (3D) transesophageal echocardiographic (TEE) imaging from the transgastric approach to visualize the submitral apparatus and quantify the lengths of the chordae tendineae by using multiplanar reconstruction analysis. Twenty-two patients who had transgastric full-volume 3D TEE data sets before mitral valve surgery underwent surgical measurement of chordal length. A short-axis plane at the chordal level was extracted from the 3D data set to identify leaflet segments and the corresponding primary chords. Then, for each chord, the optimal plane was selected to visualize and measure the entire chordal length from its origin at the leaflet margin to the papillary muscle tips. Measurements were performed at the phase of the cardiac cycle when chordal length reached its maximum. Measured values were compared with surgical measurements using linear regression and Bland-Altman analyses. One hundred forty-six primary chords were measured intraoperatively. Three-dimensional TEE imaging was able to measure the lengths of all these chords. The surgical and 3D TEE measurements (mean, 1.96 ± 0.56 vs 1.93 ± 0.50 cm, respectively) correlated highly (r = 0.93, P < .0001), with a minimal bias of 0.03 cm and narrow limits of agreement from -0.39 to 0.45 cm. Transgastric 3D TEE imaging of the submitral apparatus allows visualization and accurate measurement of chordae tendineae lengths, which may be useful for planning mitral valve repair, including percutaneous transcatheter procedures.

Usefulness of Echocardiographic Criteria for Transcatheter Aortic Valve Implantation without Balloon Predilation: A Single-Center Experience

Transcatheter aortic valve implantation (TAVI) is an alternative therapy for high-risk patients with symptomatic aortic stenosis. TAVI without balloon aortic predilation (BPD) has been found to be as feasible and safe as the standard approach with predilation. The aim of this study was to show the usefulness of transesophageal echocardiographic (TEE) criteria during patient selection for TAVI without BPD and compare the results with those from a control group. Two hundred forty-nine consecutive patients with severe symptomatic aortic stenosis underwent echocardiographic evaluation before TAVI. Two-dimensional and three-dimensional TEE imaging was used to evaluate the aortic annulus and root, leaflet mobility and degree of calcification, orifice characteristics, valve area, and aortic regurgitation. After TEE data were reviewed, patients were considered to be favorable candidates, or not, for TAVI without BPD on the basis of specific echocardiographic criteria. The mean age was 82 ± 5 years. Seventy-nine patients underwent TAVI without BPD, and 170 patients underwent TAVI with BPD. The mean aortic valve area was 0.61 ± 0.16 cm(2), and the mean aortic annular diameter was 2.2 ± 0.25 cm. In the group without BPD, Edwards SAPIEN XT valves were implanted in 64.6% (n = 51) and Medtronic CoreValve prostheses in 35.4% (n = 28). In this group, residual paravalvular aortic regurgitation immediately after valve deployment was seen in 53.2% of patients, without differences from those who underwent TAVI with BPD. Permanent pacemaker implantation was less frequent in the group of patients without BPD (6.3% vs 14.1%, P = .030). Procedure-related mortality was significantly lower in patients without BPD (2.5% vs 11.8%, P = .018). Thorough TEE assessment of aortic valve features permits the selection of patients with ideal conditions for TAVI without BPD, regardless of the type of prosthesis. Using the echocardiographic criteria described here, it is possible to achieve a good rate of procedural success with a low complication rate in patients undergoing TAVI without BPD.

Multiple papillary fibroelastomas of the aortic valve detected by real time three-dimensional transesophageal echocardiographic images

Papillary fibroelastoma (PFE) is a well-known primary cardiac tumor, but multiple PFEs are rare. We report an interesting case with multiple PFEs that were clearly demonstrated and evaluated with real time three-dimensional (RT3D) transesophageal echocardiography (TEE). A 77-year-old woman was referred to our institution with a diagnosis of osteoarthritis of the hip. Transthoracic echocardiography showed an abnormal structure on the aortic valve. Although two-dimensional TEE revealed typical characteristics of multiple PFE, RT3D TEE clearly demonstrated their number and location on the right and non-coronary cusp of the aortic valve. These results were subsequently confirmed by surgery and pathological findings. RT3D TEE is an exceptionally useful tool for pre-surgical evaluation of PFE.<Learning objective: PFE is a well-known primary cardiac tumor, but multiple PFEs are rare. We report an interesting case with multiple PFEs that was clearly demonstrated and evaluated with RT3D TEE. RT3D TEE is an exceptionally useful tool for pre-surgical evaluation of PFE.>

The Seabed-like Appearance of Atherosclerotic Plaques: Three-Dimensional Transesophageal Echocardiographic Images of the Aortic Arch Causing Cholesterol Crystal Emboli

Cholesterol crystal embolism (CCE) is a rare but important complication of endovascular procedures or anticoagulation therapy. An 84-year-old man was referred to the Gunma University Graduate School of Medicine with the diagnosis of acute myocardial infarction. After successful emergency coronary angioplasty, his serum creatinine level increased continuously. A subsequent skin biopsy confirmed that the patient had CCE. Transesophageal echocardiography (TEE) clearly demonstrated the mobile mass protruding from the complex atheroma. Three-dimensional TEE provides more precise and attractive volumetric images of the atherosclerotic plaque than two-dimensional TEE. In addition, the findings of this case revealed contrast media-induced nephropathy and CCE as possible causes of renal dysfunction after endovascular procedures.

Live three-dimensional transesophageal echocardiographic imaging of novel multielectrode ablation catheters

Use of novel, anatomically-designed multielectrode catheters for ablation of paroxysmal atrial fibrillation(AF) has been reported1 and may potentially reduce operative times, limiting exposure to radiation. The concurrence of advances in catheter technology with the introduction of live 3-Dimensional transesophageal echocardiography (3D TEE) has potential to improve the efficiency and safety of ablation procedures. A case of AF ablation using anatomically-designed multielectrode catheters guided by live 3D TEE imaging is presented. A 42-year-old man presented with a history of persistent AF having failed antiarrhythmic drug therapy and DC cardioversion. He subsequently underwent pulmonary vein isolation and LA ablation under general anesthesia using novel multielectrode ablation catheters with unique 3-dimensional configurations. During the procedure, live 3D TEE images were acquired with a 3-D Matrix TEE transducer (iE33 system, X7-2T transducer; Philips Medical Systems, Andover, MA, USA). Transseptal puncture was performed with live 3D TEE imaging and fluoroscopy. Under live 3D TEE guidance, three multielectrode ablation catheters (Ablation Frontiers, Inc., Carlsbad, CA, USA) were used for ablation and mapping of the pulmonary veins, LA roof, mitral isthmus, and LA septum. Figure 1 shows a live 3-D TEE still image of the pulmonary vein ablation catheter (PVAC) in the left atrium near the right upper pulmonary vein (RUPV); the PVAC catheter is also shown ex vivo and with fluoroscopic imaging in relation to the His-bundle(HIS) and coronary sinus(CS) catheters and TEE probe. The complex configurations of the PVAC, the multi-array ablation catheter (MAAC), and the multi-array septal catheter (MASC) can be readily appreciated with live 3D TEE (see Video Attachment) and confidence during catheter placement and ablation was subjectively greatly improved. Figure 1 Localization of intracardiac catheters using standard 2-D echocardiography is complicated by cardiac and respiratory motion, catheter orientation, and proper identification of the catheter tip. 2-dimensional imaging is further limited in clearly defining the complex configuration and larger profile of these new multielectrode ablation catheters. In the use of multipolar ablation catheters, contact between the active electrode of the ablation catheter and the targeted cardiac tissue is an essential part of reducing risk of major complications and achieving successful ablation.1 While high resolution 3D anatomical mapping of LA anatomy can be obtained by pre-interventional MRI or CT scanning, TEE offers the only practical means of live 3D imaging of cardiac tissue during the intervention. Live 3D TEE has been used with conventional ablation catheters for real-time imaging of contact without the need for excessive manipulation during LA catheter ablation for AF;2, 3 this case demonstrates that the ability to image tissue contact with live 3D TEE is preserved with novel catheters with complex geometry. The ability of live 3D TEE to image and guide the use of these novel catheters is evident, as is the potential for enhanced patient safety and reduced operative duration. As use of complex catheters increases, an expanding role for perioperative echocardiographers in guiding ablation procedures is anticipated.

Real-Time Three-Dimensional Transesophageal Echocardiography in the Intraoperative Assessment of Mitral Valve Disease

The aims of this study were to evaluate the feasibility of real-time 3-dimensional (3D) transesophageal echocardiography in the intraoperative assessment of mitral valve (MV) pathology and to compare this novel technique with 2-dimensional (2D) transesophageal echocardiography. Forty-two consecutive patients undergoing MV repair for mitral regurgitation (MR) were studied prospectively. Intraoperative 2D and 3D transesophageal echocardiographic (TEE) examinations were performed using a recently introduced TEE probe that provides real-time 3D imaging. Expert echocardiographers blinded to 2D TEE findings assessed the etiology of MR on 3D transesophageal echocardiography. Similarly, experts blinded to 3D TEE findings assessed 2D TEE findings. Both were compared with the anatomic findings reported by the surgeon. At the time of surgical inspection, ischemic MR was identified in 12% of patients, complex bileaflet myxomatous disease in 31%, and specific scallop disease in 55%. Three-dimensional TEE image acquisition was performed in a short period of time (60 +/- 18 seconds) and was feasible in all patients, with optimal (36%) or good (33%) imaging quality in the majority of cases. Three-dimensional TEE imaging was superior to 2D TEE imaging in the diagnosis of P1, A2, A3, and bileaflet disease (P < .05). Real-time 3D transesophageal echocardiography is a feasible method for identifying specific MV pathology in the setting of complex disease and can be expeditiously used in the intraoperative evaluation of patients undergoing MV repair.

Three-Dimensional Transesophageal Echocardiographic Imaging and Volumetry of Giant Left Atrial Myxomas

TWO CASES IN WHICH real-time 3-dimensional transesophageal echocardiography (RT-3D TEE) was able to accurately depict a giant atrial myxoma showing prolapse into the left ventricle with resultant ventricular inflow obstruction are reported. Volumetric calculation of these masses using 3D techniques was more accurate than traditional 2-dimensional approaches when compared with ex vivo volumetric measurements by water displacement. These cases show the efficacy and potential usefulness of RT-3D TEE in cardiac surgery.

Three-dimensional transesophageal echocardiographic imaging of a thoracic aortic dissection

aDivision of Cardiothoracic Anesthesiology, USA bDivision of Cardiothoracic Surgery, The Texas A&M University System Health Science Center College of Medicine, Scott & White Hospital, Temple, Texas, USA Correspondence to William C. Culp Jr, MD, Division of Cardiothoracic Anesthesiology, The Texas A&M University System Health Science Center College of Medicine, Scott & White Hospital, 2401 South 31st Street, Temple, TX 76508, USA Tel: +1 254 724 2407; fax: +1 254 724 5369; e-mail: [email protected]

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.

Usefulness of three-dimensional transesophageal echocardiographic imaging for evaluating narrowing in the coronary arteries

Coronary artery (CA) imaging has relied on invasive techniques for diagnosing stenotic lesions. Two-dimensional techniques are limited in obtaining optimal longitudinal views of all segments of the CA because of their spatial orientations. Three-dimensional echocardiography (3DE) may produce any desired cross-sectional views and reconstruct 3-dimensional images from a volumetric data set. Its role in CA imaging has not been fully explored. The aim of this study was to evaluate the potential of 3DE in visualizing CAs and in assessing the severity of stenosis. We performed transesophageal 3DE in 46 patients. Images were collected sequentially with the transducer rotated through 180°. From the 3DE data sets of all 46 patients, cross-sectional views and 3-dimensional images of CAs were reconstructed. For segment-by-segment comparison between CA angiography and 3DE in semiquantitative analysis of coronary stenosis, 5 segments were defined for the proximal CA tree in 20 patients who underwent both procedures. The left main, anterior descending, circumflex, and right CAs were visualized from 3DE in 100%, 100%, 98%, and 72%. The available lengths of these segments from 3DE were 12 ± 4 mm (range 4 to 22), 15 ± 6 mm (range 6 to 36), 30 ± 12 mm (range 13 to 60), and 18 ± 9 mm (range 6 to 36), respectively. Comparison between 3DE and CA angiography in semiquantitative estimation of CA stenosis resulted in complete agreement in 83% of the segments (κ value = 0.7). The sensitivity and specificity of 3DE in detecting significant stenosis (≥50%) were 84% and 97%. In conclusion, transesophageal 3DE allows imaging of the proximal CA, detection of stenotic lesions, and estimation of the severity of stenosis.

Morphology and dynamic change of discrete subaortic stenosis can be imaged and quantified with three-dimensional transesophageal echocardiography

This report describes three-dimensional transesophageal echocardiographic findings in three consecutive patients with discrete subaortic stenosis. The discrete subaortic stenosis lesions included a circumferential, a remnant crescent, and a broken fibrotic subaortic membrane. The lesions were best imaged by using a three-dimensional transesophageal echocardiography–generated “aortotomy view” of the left ventricular outflow tract immediately below the plane of the aortic valve. The three-dimensional images correlated well with surgical and pathologic findings. The three-dimensional surface areas of the left ventricular outflow tract at the level of discrete subaortic stenosis during systole (0.8 ± 0.5 cm 2) and diastole (1.7 ± 0.7 cm 2) were measured by planimetry of the three-dimensional transesophageal echocardiographic images. The novel “aortotomy view” offered by three-dimensional transesophageal echocardiography provided direct visualization and quantification of discrete subaortic stenosis in a dynamic fashion. In summary, three-dimensional transesophageal echocardiography can accurately display and quantify discrete subaortic stenosis and could be a new clinically useful tool for assessing discrete subaortic stenosis and guiding surgical and transcatheter interventions. (J Am Soc Echocardiogr 1997;10;713–6.)

Clinical application of three-dimensional transesophageal echocardiography

Three-dimensional transesophageal echocardiography is a new and evolving cardiac imaging technique. We reported our experiences of its clinical applications in 59 patients. A series of special temporal longitudinal views were selected by the frame grabber. Then the computer connected each digitized endocardial surface of the longitudinal views according to their spatial position and reconstructed the three-dimensional, cardiac shaded picture with gray scale. The three-dimensional transesophageal echocardio-graphic images were divided into three areas. The right area was right anterior to the esophagus and included such structures as the superior vena cava, right atrium, interatrial septum, and left atrium; the size, shape, and location of an atrial septal defect could be clearly shown. In the middle area the origin and the course of the two great arteries could be visualized, thus facilitating the diagnosis of transposition of the great arteries; in patients with obstruction of the right ventricular outflow tract, the circular ridgelike narrowing in the right ventricle was clearly visualized. In the left area the contour and size of the left ventricle and left atrium and the shape and point of coaptation of the mitral valve could be demonstrated; in patients with mitral valve prolapse, part of either leaflet protruded into the left atrium and appeared as a spoonlike depression in the mitral valve. Other entities subjected to three-dimensional transesophageal echocardiographic reconstruction included cor triatriatum, left atrial myxoma, aneurysm of sinus of Valsalva, dissecting aortic aneurysm, mitral stenosis, mitral regurgitation, and mitral valve prolapse. Therefore three-dimensional transesophageal echocardiography allows unique identification and ultimately superior imaging of the various cardiovascular structures in both congenital and acquired heart diseases. This technology also facilitates understanding of the spatial relations of the cardiovascular structures, which has been hitherto considered difficult to observe with conventional two-dimensional tomography in a living subject.