Impact of three-dimensional echocardiography in valvular heart disease

PURPOSE OF REVIEW: Recent advances in the field of three-dimensional (3D) echocardiography have allowed improved visualization of cardiac structures. These advances have also provided valuable insights into cardiac function. The purpose of this review is to describe the recent developments in 3D echocardiography in assessing valvular heart disease. RECENT FINDINGS: Application of 3D echocardiography to valvular heart disease has improved with advances made in both the hardware and software components of 3D ultrasound systems. The most significant advancement has been the development of a matrix transducer that is capable of rapid real-time 3D acquisition and rendering. There have been many studies evaluating 3D echocardiographic assessment of mitral valve disease, aortic valve disease, as well as congenital heart disease using both real-time 3D transthoracic echocardiography (TTE) as well as off-line reconstructed 3D images from transesophageal echocardiography (TEE) using post image processing. More recent studies have combined the structural 3D information with color Doppler 3D imaging, providing qualitative functional information. SUMMARY: Developments in the field of 3D ultrasound imaging have allowed better qualitative assessment of valvular structures. The addition of color flow Doppler to the 3D imaging has provided improved visualization of regurgitant lesions and holds great promise for improved quantitative assessment of such lesions. The ongoing miniaturization of transducers and improvements in hardware and software components of ultrasound systems will certainly enhance both the ease of image acquisition as well as image quality, which should result in more precise quantitation of valvular dysfunction. However, clinical benefits of 3D echocardiography are yet to be demonstrated in properly conducted clinical trials, which are needed for wider acceptance of this technique.     

Comparison of transthoracic and transesophageal echocardiography for assessment of left-sided valvular regurgitation

To compare transthoracic and transesophageal echocardiography in the clinical assessment of left-sided valvular regurgitation, 118 patients who underwent both transesophageal and transthoracic echocardiographic studies within a 24-hour period were included in this study. Presence or absence of aortic regurgitation was identified concordantly by both techniques in 93 patients (79%). Complete agreement between both techniques was found in 88 patients (75%). Presence or absence of mitral regurgitation was identified concordantly by both techniques in 89 patients (75%). Complete agreement in grade was found in only 74 patients (63%). Twentynine patients (25%) had mitral regurgitation detected by transesophageal echocardiography, but not by transthoracic echocardiography. Four of these patients (14%) had significant (2 to 3+) mitral regurgitation. Differences between transesophageal and transthoracic echocardiography do not appear to be clinically important in patients with aortic regurgitation. In mitral regurgitation, significant differences exist between these 2 techniques, with transesophageal echocardiography being much more sensitive.     

Adult Perioperative Echocardiography: Anatomy,Mechanisms and Effective Communication

Intra-operative transesophageal echocardiography (TEE) is a mature imaging technique which represents the premier surgical quality control instrument in the contemporary operating room. In adult cardiac surgery, management of valvular heart disease and related structural cardiac abnormalities derive the most benefit from perioperative echocardiography which includes pre-operative transthoracic echocardiography, intra-operative TEE and post-surgical echocardiographic surveillance. This review discusses the theoretical background upon which these imaging techniques are built-on, and offers a practical state-of-the-art guide on their application, emphasizing the importance of anatomic relationships, mechanisms of dysfunction and effective communication with our surgeons.     

Valvular heart disease. The value of 3-dimensional echocardiography

Significant advances in 3-dimensional echocardiography (3DE) technology have ushered its use into clinical practice. The recent advent of real-time 3DE using matrix array transthoracic and transesophageal transducers has resulted in improved image spatial resolution, and therefore, enhanced visualization of the pathomorphological features of the cardiac valves compared with previously used sparse array transducers. It has enabled an unparalleled real-time visualization of valves and subvalvular anatomic features from a single volume acquisition without the need for offline reconstruction. On-cart or offline post-processing using commercially available and custom 3-dimensional analysis software allows the quantification of multiple parameters, such as orifice area, prolapse height and volume in mitral valve disease, area of the left ventricular outflow tract, and tricuspid annular geometry. In this review, we discuss the incremental role of 3DE in evaluating valvular anatomic features, volumetric quantification, pre-surgical planning, intraprocedural guidance, and post-procedural assessment of valvular heart disease.     

微创胸骨下段小切口室间隔缺损封堵术的临床分析

目的 分析总结微创经胸骨下段小切口室间隔缺损（VSD）封堵术的临床应用价值.方法 回顾分析我科2011年5月至2013年5月经胸骨下段小切口微创封堵术治疗VSD的患者50例.术前行经胸超声心动图评估筛选适合封堵的VSD患者,术中行经食管超声心动图再次评估VSD是否适合封堵治疗,并确定封堵器型号,引导封堵器释放,评判封堵效果,出院后对患者进行随访.结果 50 例VSD患者中48 例成功封堵,成功率96%,2 例封堵不成功中转体外循环下修补.随访6～24 个月,无残余漏,心功能改善.结论 在超声心动图（经胸及经食管）配合下,经胸骨下段小切口微创封堵VSD技术不需要体外循环辅助,是一种简单、安全、有效的治疗方法.     

Value of transesophageal echocardiography as an adjunct to transthoracic echocardiography in evaluation of native and prosthetic valve endocarditis

To determine if transesophageal echocardiography provides better visualization of valvular vegetations than transthoracic echocardiography, we used both methods to evaluate 24 consecutive patients (mean age, 54 years; 15 female patients and nine male patients) referred for symptoms suggestive of infectious endocarditis. Ten of the 24 patients had one or more valvular prostheses. Echocardiograms were classified as positive or negative based on visualization of valvular vegetations or abscesses. Of ten patients with a final diagnosis of infectious endocarditis on extended follow-up, transthoracic echocardiography was positive in five patients. Transesophageal echocardiography not only yielded abnormal findings in all ten of these patients, but also revealed additional information in four of the five patients with abnormal transthoracic echocardiographic examinations. Among the 14 patients who, on subsequent follow-up, were found not to have infectious endocarditis, transthoracic echocardiography was normal in 13 and falsely abnormal in one. Transesophageal echocardiography revealed no evidence of infectious endocarditis in any of these patients. The ten patients who were determined to have infectious endocarditis all had positive blood cultures and no alternative cause for their clinical presentation; in seven patients in this group who underwent operative or postmortem evaluation, infectious endocarditis was confirmed. All patients without infectious endocarditis were demonstrated to have other causes for their clinical presentation. We conclude that transesophageal echocardiography is a highly valuable test in the work-up of patients with suspected infectious endocarditis, especially those patients with inconclusive or normal transthoracic echocardiograms. In addition, transesophageal echocardiography may be of benefit to patients with previously documented infectious endocarditis and a complicated clinical course in whom additional cardiac lesions are suspected but not demonstrated by transthoracic echocardiography.     

Single-plane transesophageal echocardiography for assessing function of mechanical or bioprosthetic valves in the aortic valve position.

To assess the value and limitations of single-plane transesophageal echocardiography in the evaluation of prosthetic aortic valve function, 89 patients (69 mechanical and 20 bioprosthetic aortic valves) were studied by combined transthoracic and transesophageal 2-dimensional and color flow Doppler echocardiography. In the assessment of aortic regurgitation, the transthoracic and transesophageal echocardiographic findings were concordant in 71 of 89 patients (80%). In 8 patients, the degree of aortic regurgitation was underestimated by the transthoracic approach; in each case the quality of the transthoracic echocardiogram was poor. In 10 patients, transesophageal echocardiography failed to detect trivial aortic regurgitation due to acoustic shadowing of the left ventricular outflow tract from a mechanical valve in the mitral valve position. Transesophageal echocardiography was superior to transthoracic echocardiography in diagnosing perivalvular abscess, subaortic perforation, valvular dehiscence, torn or thickened bioprosthetic aortic valve cusps, and in clearly distinguishing perivalvular from valvular aortic regurgitation. Transesophageal echocardiography correctly diagnosed bioprosthetic valve obstruction in 1 patient, but failed to diagnose mechanical valve obstruction in another. In conclusion, transesophageal echocardiography offers no advantage over the transthoracic approach in the detection and quantification of prosthetic aortic regurgitation unless the transthoracic image quality is poor. Transesophageal echocardiography is limited in detecting mechanical valve obstruction and in detecting aortic regurgitation in the presence of a mechanical prosthesis in the mitral valve position. However, it is superior to transthoracic echocardiography in identifying perivalvular pathology, differentiating perivalvular from valvular regurgitation and in defining the anatomic abnormality responsible for the prosthetic valve dysfunction. Combined transthoracic and transesophageal examination provides complete anatomic and hemodynamic assessment of prosthetic aortic valve function.     

Improved detection of infective endocarditis with transesophageal echocardiography.

The incremental advantage of transesophageal echocardiography was determined by comparing results of paired transthoracic and transesophageal echocardiographic examinations performed in 61 patients for evaluation of suspected infective endocarditis. According to clinical and pathologic data, 31 of 61 (51%) patients had finding that were positive for infective endocarditis. Studies were graded as positive or negative for vegetations and were also graded for image quality. The sensitivity of transesophageal echocardiography in detecting vegetations was 88% versus 30% for transthoracic studies (p less than 0.01). For patients with aortic valve infective endocarditis, transesophageal sensitivity was 88% versus 25% for transthoracic sensitivity, because transesophageal echocardiography successfully separated vegetations from chronic valve disease caused by sclerosis or calcification (p less than 0.01). For patients with mitral valve infective endocarditis, transesophageal sensitivity was 100% versus 50% for transthoracic sensitivity, because transesophageal echocardiography distinguished vegetations from myxomatous changes or detected vegetations on prosthetic valves (p less than 0.01). Thus transesophageal echocardiography improves recognition of infective endocarditis, particularly in the presence of underlying valvular disease.     

Interventional Echocardiography

Echocardiography guidance for interventions in the catheterization laboratory allows for reduction in radiation exposure from fluoroscopy as well as superior anatomic definition and visualization. The additional information provided over fluoroscopy has translated into an increasing use during interventional procedures. Procedures such as transeptal puncture, percutaneous valvular interventions, myocardial biopsy, echo-guided pericardiocentesis and other interventions have evolved to a complexity level that requires combined echocardiographic and fluoroscopic guidance. Different imaging modalities are utilized in the catheterization laboratory including intracardiac echocardiography, two-dimensional (2D) or three-dimensional (3D) transthoracic echocardiography, and 2D or 3D transesophageal echocardiography. This review is intended to provide an overall summary of the impact echocardiography has had in the catheterization laboratory. We will describe how echocardiography is utilized to guide a diverse array of interventional procedures, emphasizing specific practical issues with respect to echocardiographic guidance of interventional procedures and also pointing out the limitations of echocardiography.     

Application of transesophageal echocardiography in minimally invasive surgical closure of ventricular septal defects

We sought both to evaluate the clinical value of transesophageal echocardiography in minimally invasive surgical closure of ventricular septal defects and to evaluate the feasibility, safety, and efficacy of the surgical occlusion procedure. We selected 49 pediatric patients who had perimembranous ventricular septal defects as determined by preoperative transthoracic echocardiographic examination. After the patients were under general anesthesia, we used transesophageal echocardiography to determine the number of defects and their positions, shapes, and sizes, these last in order to choose the appropriate occluder. Under transesophageal echocardiographic monitoring and guidance, we introduced and deployed the occluder. The evaluation of therapy was performed by means of transesophageal echocardiography immediately after occluder release. All patients underwent follow-up transthoracic echocardiography within 2 to 5 postoperative days. Satisfactory occluder deployment was achieved in 38 patients. No death occurred. No occluder displacement or valve dysfunction was observed during the last transesophageal echocardiographic study. In addition, follow-up by transthoracic echocardiography showed improvement of left ventricular dimensions and ejection fractions. Our initial experience has been encouraging. Transesophageal echocardiography plays a crucial role in performing minimally invasive surgical closure of cardiac defects. It enables the feasible, safe, and effective closure of ventricular septal defects. However, larger sample sizes and longer-term follow-up are necessary for the accurate evaluation of this procedure's safety and effectiveness as an alternative to cardiopulmonary bypass surgery and transcatheter closure of congenital cardiac defects.     

Dynamic three-dimensional echocardiography in the assessment of cor triatriatum

Classic cor triatriatum sinistrum is a rare cardiac malformation to be found in the adult. One year after surgical correction of an atrial septal defect in a 55-year-old man, cor triatriatum sinistrum was diagnosed by transesophageal echocardiography. We compared transthoracic echocardiography, transesophageal echocardiography, and cardiac catheterization to dynamic three-dimensional echocardiography (3-D echo) which offers a new, noninvasive approach to determine the opening size between the accessory and the true left atrium. The findings by 3-D echo, confirmed by left heart catheterization, showed that the accessory membrane was not stenosing. Surgical correction was therefore not indicated in this patient.     

Study of infectious endocarditis using Doppler echocardiography

Infective endocarditis is still a common and serious disease. Echocardiography is an essential complementary investigation in this condition. Its value in the diagnosis of valvular vegetations has become more accurate since the introduction of two-dimensional and transesophageal echocardiography. Transesophageal echocardiography is currently the most reliable non-invasive technique for demonstrating small vegetations of less than 5 mm diameter. The diagnosis and surveillance of complications (valvular destruction, ring abscess) are also privileged indications of transthoracic and transesophageal echocardiography coupled with intracardiac Doppler blood flow studies. The finding of these lesions may sometimes lead to early surgical management.     

Real-time intracardiac two-dimensional echocardiography: an experimental study of in vivo feasibility, imaging planes, and echocardiographic anatomy

The traditional transthoracic and transesophageal echocardiographic examination have proven to be useful imaging tools for studying cardiac morphology, pathology, and function. Recently, catheter-based ultrasound transducers have been available for intravascular ultrasonic imaging. We supposed that echocardiographic examination performed from within the heart itself can provide useful information about cardiac structure and function, especially in settings where transthoracic or transesophageal echocardiography may be technically difficult to perform or poorly tolerated by the patient. To explore this concept, we performed intracardiac echocardiography in vivo in 22 dogs using both 5-MHz and 20-MHz transducers. High-quality images were obtained in all animals. Using the higher frequency transducer, detailed images with only a limited depth of field were obtained. With the 5-MHz transducer, a comprehensive cardiac examination was feasible from within the right atrium and inferior vena cava. We were able to visualize the great vessels, all cardiac valves, and cardiac chambers in a multitude of imaging planes. Alterations in ventricular function were instantly recognized. Color Doppler capabilities allowed visualization of flow abnormalities as well. We conclude that intracardiac echocardiography is feasible and could be potentially useful in certain clinical situations. With further research and development, this technique may have an important clinical impact in cardiac therapy and diagnosis.     

Morphologic features of carcinoid heart disease as assessed by three-dimensional transesophageal echocardiography

Background: Carcinoid heart disease (CHD) is a rare cause of valvular heart disease and carries a poor prognosis. CHD has a unique morphology and echocardiographic features that predominantly involve right‐sided valvular structures. The diagnosis of CHD is usually made by two‐dimensional transthoracic echocardiography (TTE). With the superior spatial resolution of real time three‐dimensional transesophageal echocardiography (3DTEE), structural changes that occur in patients with CHD‐associated valvular heart disease can be examined in greater detail. We undertook this study to examine the incremental value of 3DTEE in the diagnosis of CHD. Methods: A total of four patients with CHD underwent TTE, transesophageal echocardiography (TEE), and 3DTEE as part of their routine clinical evaluation. Results: TTE and TEE for all four patients revealed thickened, fibrosed, retracted, and malcoapted tricuspid leaflets with wide‐open tricuspid valve regurgitation. 3DTEE en face imaging of the tricuspid valve demonstrated the characteristic morphologic features of CHD more clearly in all four patients. Conclusions: 3DTEE provides substantial incremental value over TTE in the assessment of characteristic CHD pathology and thus enhances the echocardiographic diagnosis of CHD. (Echocardiography 2010;27:1098‐1105)     

Transesophageal echocardiography: State-of-the art and future directions

Transesophageal echocardiography complements transthoracic examination in 5–10% of patients referred to the echocardiographic laboratory. Clinical indications for performing this procedure are continually evolving. The semi-invasive nature of this procedure necessitates that it be judiciously used and that trained personnel undertake the procedure. Complications of the procedure need to be kept in mind. Future directions in the development of this technology involve newer, muttiplanar, muttifrequency transducers, digital archiving and retrieval, wide-field imaging, and 3-dimensional reconstruction. For the present, transthoracic echocardiography must remain the primary echocardiographic window imaging the heart, with defined clinical applications for transesophageal echocardiography.     

The limitations of echocardiography in the overall diagnosis of the morphological lesions associated with infective endocarditis: comparison of echocardiographic and surgical findings

Echocardiography is commonly accepted as the method of choice for the non-invasive diagnosis of vegetations and other lesions associated with infective endocarditis. To assess the accuracy of echocardiography in the overall diagnosis of the morphological cardiac lesions we retrospectively analyzed and compared the preoperative echocardiographic data with the surgical findings of 120 consecutive cases operated for infective endocarditis. Transthoracic echocardiography (TTE) was used in 60 cases (51 with native and 9 with prosthetic valves), both TTE and transesophageal echocardiography (TEE) in 50 (26 with native and 24 with prosthetic valves) and only TEE in 10 patients who underwent emergency surgery. The echocardiographic diagnosis was correct in all the cases, but incomplete in 26 (16 with native and 10 with prosthetic valves). Most of the incomplete diagnoses occurred regarding vegetations, perforations of the valvular leaflets and perivalvular abscesses. There were no differences between aortic or mitral valves (14/66 vs 11/60; p = ns), native or prosthetic (16/79 vs 10/37; p = ns), TTE or TEE (13/60 vs 13/60; p = ns); however, TEE was performed in more complex cases and in severely ill patients. In six of the incomplete diagnoses, echocardiography preceded surgery by one week or more, and in six the mistakes were not confirmed by the reviewer. In conclusion, our study suggests that an echocardiographic diagnosis of endocarditis may be correct but sometimes incomplete. In patients without prosthetic valves who have a technically-adequate transthoracic echocardiogram, transesophageal echocardiography is not indispensable but should be chosen from time to time. However, the patients with endocarditis and no contraindication to the transesophageal procedure should undergo both transesophageal and transthoracic echocardiography before surgery in order to obtain as much and the most definite information possible. An echocardiographic study should be repeated just before any surgical procedures in patients with active endocarditis. Finally, it needs to be emphasized that the training and clinical judgement of the operator performing the study are important elements determining the results of echocardiographic study.     

Transesophageal echocardiography in critically ill patients

The feasibility, safety and clinical impact of transesophageal echocardiography were evaluated in 51 critically ill intensive care unit patients (28 men and 23 women; mean age 63 years) in whom transthoracic echocardiography was inadequate. At the time of transesophageal echocardiography, 30 patients (59%) were being mechanically ventilated. Transesophageal echocardiography was performed without significant complications in 49 patients (96%), and 2 patients with heart failure had worsening of hemodynamic and respiratory difficulties after insertion of the transesophageal probe. The most frequent indication, in 25 patients (49%), was unexplained hemodynamic instability. Other indications included evaluation of mitral regurgitation severity, prosthetic valvular dysfunction, endocarditis, aortic dissection and potential donor heart. In 30 patients (59%), transesophageal echocardiography identified cardiovascular problems that could not be clearly diagnosed by transthoracic echocardiography. In the remaining patients, transesophageal echocardiography permitted confident exclusion of suspected abnormalities because of its superior imaging qualities. Cardiac surgery was prompted by transesophageal echocardiographic findings in 12 patients (24%) and these findings were confirmed at operation in all. Therefore, transesophageal echocardiography can be safely performed and has a definite role in the diagnosis and expeditious management of critically ill cardiovascular patients.     

Pränatale Herzdiagnostik mittels zwei- und dreidimensionaler Fetalechokardiographie

INTRODUCTION: With increasing experience of obstetric sonographers, a higher proportion of cardiac malformations is found antenatally. However, undiagnosed fetal cardiac defects still result in a significant pre- and postnatal morbidity and mortality. The purpose of two- and three-dimensional echocardiographic imaging in the fetus is to provide clear representations of the underlying cardiac and vascular anatomy. Studies on pre- and postnatal echocardiography have shown these techniques to provide an adequate form of image display for comprehensive assessment of most cases with congenital heart disease. METHODS: To date, two different methods are used for three-dimensional echocardiography in the fetus. The technique currently employed at numerous institutions derives from a complex assembly of sequentially acquired and reconstructed two-dimensional images and is analogous to the 3-D technology assessed in studies on neonates, children, and adults. Although an electromagnetic location device is used to register transducer position during data acquisition, this technique has important limitations due to fetal movement artifacts and difficulties in cardiac gating. This often results in inadequate image quality when compared with 2-D echocardiography. Recent progress in the design and fabrication of higher-frequency real-time volumetric transducers has greatly improved 3-D echocardiographic imaging resolution and allows more immediate three-dimensional "on-line" analysis of cardiac anatomy. CONCLUSIONS: Advantages of 3-D fetal echocardiography include the ability to slice the acquired 3-D volume data into an infinite number of two-dimensional cross sections, and the ability to reconstruct unique three-dimensional views not seen with two-dimensional imaging. However, considering the current limitations and the time needed for 3-D image processing, its practical clinical relevance in the antenatal situation is not yet clear.     

Feasibility, Accuracy, and Incremental Value of Intraoperative Three-Dimensional Transesophageal Echocardiography in Valve Surgery

In this prospective trial, intraoperative 2-dimensional (2-D) and 3-dimensional (3-D) transesophageal echocardiography (TEE) examinations were performed on 60 consecutive patients undergoing cardiac valve surgery. Both 2-D (including color flow and Doppler data) and 3-D images were reviewed by blinded observers, and major valvular morphologic findings recorded. In vivo morphologic findings were noted by the surgeon and all explanted valves underwent detailed pathologic examination. To test reproducibility, 6 patients also underwent 3-D TEE 1 day before surgery. A total of 132 of 145 attempted acquisitions (91%) were completed with a mean acquisition time of 2.8±0.2 minutes. Acquisition time was significantly shorter in patients with regular rhythms. Reconstructions were completed in 121 of 132 scans (92%) and there was at least 1 good reconstruction in 56 of 60 patients (93%). Mean reconstruction time was 8.6 ± 0.7 minutes. Mean effective 3-D time, which was the time taken to complete an acquisition and a clinically interpretable reconstruction, was 12.2 ± 0.8 minutes. Intraoperative 3-D echocardiography was clinically feasible in 52 patients (87%). Three-D echocardiography detected most of the major valvular morphologic abnormalities, particularly leaflet perforations, fenestrations, and masses, confirmed on pathologic examination. Three-D echocardiography predicted all salient pathologic findings in 47 patients (84%) with good quality images. In addition, in 15 patients (25%), 3-D echocardiography provided new additional information not provided by 2-D echocardiography, and in 1 case, 3-D echocardiographic findings resulted in a surgeon’s decision to perform valve repair rather than replacement. In several instances, 3-D echocardiography provided complementary morphologic information that explained the mechanism of abnormalities seen on 2-D and color flow imaging. In the reproducibility subset, preoperative and intraoperative 3-D imaging detected a similar number of findings when compared with pathology. Thus, in routine clinical intraoperative settings, 3-dimensional TEE is feasible, accurately predicts valve morphology, and provides additional and complementary valvular morphologic information compared with conventional 2-D TEE, and is probably reproducible.