The value of transesophageal echocardiography in children with congenital heart disease

Transesophageal Echocardiography in Tetralogy of Fallot

Transesophageal echocardiography (TEE) plays an important role in the anatomical, functional, and hemodynamic assessment of patients with congenital heart disease (CHD). This imaging approach has been applied to both children and adults with a wide range of cardiovascular malformations. Extensive clinical experience documents significant contributions, particularly in the perioperative setting. In fact, in the current medical era, many consider this technology to be an essential adjunct to surgical and anesthetic management in CHD. This review focuses on the applications of TEE in patients with tetralogy of Fallot (TOF), the most common form of cyanotic heart disease. Emphasis is given to the perioperative use of this imaging modality and benefits derived during the prebypass and postbypass periods. Limitations and pitfalls relevant to the TEE assessment in patients with this anomaly are also addressed.

What is new in pediatric cardiac imaging?

Cardiac imaging has had significant influence on the science and practice of pediatric cardiology. Especially the development and improvements made in non-invasive imaging techniques, like echocardiography and cardiac magnetic resonance imaging (MRI), have been extremely important. Technical advancements in the field of medical imaging are quickly being made. This review will focus on some of the important evolutions in pediatric cardiac imaging. Techniques such as intracardiac echocardiography, 3D echocardiography, and tissue Doppler imaging are relatively new echocardiographic techniques, which further optimize the anatomical and functional aspects of congenital heart disease. Also, the current standing of cardiac MRI and cardiac computerized tomography will be discussed. Finally, the recent European efforts to organize training and accreditation in pediatric echocardiography are highlighted.

Transesophageal echocardiography (TEE) in congenital heart disease with focus on the adult

Remarkable innovations in medical and surgical approaches over the past several decades now allow for correction of major cardiac defects in children, even in early infancy. These advances have provided for survival of many pediatric patients with congenital heart disease into adulthood. Although transthoracic echocardiography remains the primary imaging technique for the characterization of simple and complex congenital cardiovascular malformations in the pediatric and adult age groups, high-resolution transesophageal imaging has markedly expanded the anatomic and hemodynamic assessment in these patients. The benefits of this imaging approach apply particularly to those with challenging or limited transthoracic examinations or poorly characterized congenital cardiovascular malformations. The utility of TEE in defining the anatomy of the usual spectrum of congenital cardiac malformations is well established. The transesophageal approach has been shown to provide additional diagnostic information over conventional transthoracic imaging for specific structural cardiac anomalies and in the perioperative setting, the opportunity for confirmation of preoperative diagnoses, and modification of the surgical plan if new or different pathology is identified. This imaging modality also may reliably provide for immediate detection of suboptimal surgical repairs and significant postoperative residua, potentially improving the efficacy of the surgical intervention. This accounts for the vital role of this technology in perioperative management and integration into the standard of care in many congenital heart centers. The usefulness of TEE also has been documented during diagnostic and therapeutic cardiac catheterizations of patients with structural cardiac anomalies, allowing for safer and more effective application of these technologies. The experience supports the use of TEE as a useful approach in the surveillance of the adult with operated and unoperated congenital heart disease.

Transesophageal imaging of the mid to distal left pulmonary artery in congenital heart disease

We assessed how well transesophageal echocardiography (TEE) images the left pulmonary artery (LPA) in congenital heart disease (CHD). Seventy-nine consecutive patients with CHD were studied. Ideal imaging displayed the mid to distal LPA from the takeoff of the upper lobe artery through the second bifurcation. Imaging quality was graded from 1 (excellent) to 5 (not visualized). Imaging quality was excellent in 8 (10%) patients, good in 25 (32%), fair in 23 (29%), and poor in 12 (15%); the LPA was not visualized in 11 (14%) patients. Imaging grade averaged 2.9 +/- 1.2 (SD) and correlated poorly with weight (r = 0.24) but was better in patients without prior operation (grade 2.8 vs 3.3, P <.05). In 2 patients, TEE showed residual stenosis. Thus informative LPA imaging by TEE can be achieved in many patients with CHD and has the potential to change intraoperative or postoperative treatment.

Pediatric echocardiography: applications and limitations

Echocardiography is an extraordinarily useful imaging technique in fetuses, infants, children, and adolescents. Recent technologic innovations have expanded its versatility in the pediatric population. However, limited societal resources, limitations inherent to ultrasound imaging, and numerous imaging options even within the field of pediatric echocardiography necessitate the discriminate and thoughtful use of echocardiography in children. The clinical assessment remains a critical prelude to echocardiographic examination of the pediatric cardiovascular system.

Feasibility study: transesophageal echocardiography with a 10F (3.2-mm), multifrequency (5.5- to 10-MHz) ultrasound catheter in a small rabbit model

Transesophageal echocardiography (TEE) is useful in children with congenital heart defects. However, because of available probe size (>/=7 mm diameter), its use is limited to patients weighing more than 3 kg. The aim of this study was to determine the feasibility of TEE in a small animal model by using a 10F (3.2-mm) intravascular ultrasound tipped catheter with a monoplane (longitudinal) 5.5- to 10-MHz phased vector array transducer. Ten New Zealand White rabbits (400 to 3400 g; mean 1580 g) underwent TEE. With animals under general sedation, the probe was blindly introduced into the esophagus. All intracardiac and extracardiac structures were examined, and the images were stored and independently reviewed. All pertinent intracardiac and extracardiac structures were identified except in the 3 smallest rabbits (400 to 600 g). Doppler hemodynamics and color Doppler were possible in each animal. Frequency agility (5.5 to 10 MHz) facilitated optimization of image resolution and penetration. Certain transgastric, 4-chamber, and short-axis views were limited because of the monoplane array. No overt adverse effects were associated with the procedure. Diagnostic TEE can be performed in a small animal model with a 10F, 5.5- to 10-MHz phased vector array ultrasound catheter. Our study suggests that this system has potential in performing diagnostic TEE safely in small, even premature, neonates.

Intraoperative transesophageal echocardiography in congenital heart disease

This article reviews the use of intraoperative echocardiography during repair of congenital heart defects. Although initial experience was generated using epicardial transducers, there has been a trend in recent years toward the use of transesophageal echocardiography (TEE) in the operating room. This has encouraged increased involvement from cardiologists and anesthesiologists. New probe designs have provided biplane imaging via the TEE approach in infants weighing more than 2.5 kg. Smaller infants may still require epicardial imaging, so it is helpful for surgeons to maintain some skill in this technique. This article reviews the utility of intraoperative echocardiography for various congenital heart defects by providing examples from our experience at Duke University Medical Center since 1987 with close to 2,000 cases. Furthermore, we review and report for the first time our experience with TEE since 1993 in the operating room during infant heart surgery (493 patients). Along with this experience, we provide a review of important series in the literature to outline recommendations for the use of echocardiography during infant heart repair.

Value and impact of necropsy in paediatric cardiology

OBJECTIVE

To assess the current value of necropsy in paediatric cardiology and cardiothoracic surgery and determine its potential impact on clinical practice.

DESIGN AND SETTING

Descriptive study of all paediatric cardiac deaths occurring over four years in a tertiary referral centre. Data were obtained from reviewing the hospital files, available necropsy records and specimens, and audit reports.

PATIENTS

Paediatric patients with congenital or acquired heart disease, who died of a cardiac cause between January 1992 and July 1995. Inclusion criteria were that the diagnosis of heart disease was made before death, and that patients were managed thereafter medically and/or surgically at the referral centre. The value of necropsy was assessed according to its contribution in establishing the cause of death (confirmed, clarified, precise cause of death uncertain) and the anatomy (simple confirmation or additional information provided). For cases not submitted to necropsy the clinical information relating to the cause of death was assessed and the case assigned as cause of death firm, uncertain, or unknown.

RESULTS

One hundred and six deaths were identified (61 males, age at death: one day to 20 years). Seventy occurred early (a month or less) after surgery and were graded as postoperative deaths. The rest were considered to be either medical or late surgical deaths. Necropsy was performed in 59 (55.6%). The precise cause of death was confirmed in 33 (55.9%), clarified in 22 (37.3%), and remained uncertain in four (7.8%). Additional information regarding the anatomy was found in eight (13.6%) cases. In five cases (8.5%) the necropsy detected findings which, if known before death, would probably have improved outcome. For the patients dying without a necropsy, the cause of death remained uncertain in 10 (21.3%) and unknown in seven (14.9%). In 36% of cases, therefore, a firm cause of death that might have been provided by a necropsy was missing.

CONCLUSION

In paediatric cardiology necropsy continues to provide clinically relevant information at a high level. It remains vital for ensuring quality of medical care, in instigating improvements in future management, and increasing understanding of congenital heart disease. The procedure should therefore be sought actively in all cases.

Reproducibility of quantitative pediatric transesophageal echocardiography

Transesophageal echocardiography (TEE) is commonly used to monitor cardiac function and to assess cavitary size. For the interpretation of quantitative echocardiographic data, the degree of their reproducibility should be considered. The variability of quantitative TEE was evaluated in this study. To assess intraobserver, beat-to-beat, interobserver, and repositioning variability, TEE examinations of 46 patients with congenital heart defects were analyzed. The mean beat-to-beat variability of 8.5% (range 4.2% to 12.3%) exceeded the mean intraobserver variability of 4.9% (1.9% to 8.1%). The mean interobserver difference between two observers was 3.4% (0.2% to 11.9%). Differences in image acquisition caused by repositioning of the transesophageal probe contributed the most (6.4% to 13.3%; mean 10.5%) to the variability of two-dimensional TEE. Changes seen on TEE studies should be interpreted as abnormal only when they exceed the total variability of this method.

Transoesophageal echocardiography in congenital heart disease

The development of paediatric transoesophageal ultrasound imaging represents an important advance in the diagnosis and management of the patient with congenital heart disease. Although primary diagnostic transoesophageal studies are seldom indicated in infants and unoperated children, they have an important role in the older child, especially where there has been prior cardiac surgery. Diagnostic studies are most appropriate for abnormalities of venous return, the atria, atrioventricular valves and the left ventricular outflow tract. Two other important areas in which transoesophageal imaging is playing an increasing role in the management of the paediatric patient is in monitoring of surgical repair.

Biplane intraoperative transesophageal echocardiography in congenital heart disease

OBJECTIVE

To evaluate the accuracy, value, and safety of biplane intraoperative transesophageal echocardiography (TEE) in patients with congenital cardiac malformations.

DESIGN

We reviewed the results of the first 104 consecutive biplane intraoperative TEE examinations performed during the repair of congenital heart defects at the Mayo Clinic.

MATERIAL AND METHODS

TEE results were analyzed for accuracy of diagnosis, effect on the surgical procedure, and associated complications. In a subjective analysis, the relative contributions and advantages of each imaging plane (transverse and longitudinal) were also assessed.

RESULTS

Biplane TEE had "significant impact" on intraoperative management in 17 of 104 examinations (16.3%). Preoperative TEE altered the planned procedure in 11 patients (10.6%). Postbypass biplane TEE led to immediate revision of the initial repair in nine patients (8.7%). Patients who underwent modified Fontan operations or subaortic resections had the greatest frequency of significant impact (40% [P = 0.006] and 33% [P = 0.03], respectively). No major complications were associated with TEE. For a complete examination, use of both imaging planes was necessary in all the patients studied.

CONCLUSION

Biplane TEE is an accurate, valuable, and safe addition to the perioperative care of patients with congenital heart disease. Although intraoperative TEE is not needed in all operations for congenital heart disease, we recommend that biplane intraoperative TEE be performed routinely during modified Fontan procedures, subaortic resections, and other intracardiac operations for complex congenital cardiac malformations.

Diagnosis in adolescents and adults with congenital heart disease. Prospective assessment of individual and combined roles of magnetic resonance imaging and transesophageal echocardiography

BACKGROUND

The inability to obtain complete diagnoses with transthoracic echocardiography in many adults with congenital heart disease provided the incentive to evaluate prospectively the individual and combined roles of magnetic resonance imaging (MRI) and transesophageal echocardiography (TEE) as "second-line" techniques for unresolved diagnostic problems.

METHODS AND RESULTS

Eighty-five patients were studied; 81 had MRI with a 0.5-T magnet to obtain spin-echo images, cine-MRI, and flow-velocity maps. Seventy-nine patients had TEE (37 biplane). A simple score (range, 0 to 1) was used for quantification of the results of MRI and TEE alone, for their comparison (in the 75 patients who had both), and for assessment of their combination. MRI, TEE, or their combination achieved a score of at least 0.75 in 18 of 25 diagnostic categories. A summary of the scores showed that for intracardiac anatomy. MRI scored 0.34, TEE scored 0.71 (P < .0001), and MRI plus TEE scored 0.84 (P < .003); for extracardiac anatomy, MRI scored 0.76, TEE scored 0.23 (P < .0001), and MRI plus TEE scored 0.84 (P = NS); and for hemodynamics and function, MRI scored 0.58, TEE scored 0.41 (P < .05), and MRI plus TEE scored 0.67 (P = NS). Total scores were MRI, 0.52; TEE, 0.50 (P = NS); and MRI plus TEE, 0.80 (P < .0001). MRI and TEE were inadequate for collateral and coronary arteries and pulmonary vascular resistance. Cine-MRI and flow-velocity maps comprised 43% of the MRI scores. Biplane TEE was better than single plane (scores of 0.59 versus 0.42, P < .0001).

CONCLUSIONS

MRI and TEE are important and complementary "second-line" investigations for congenital heart disease. Analysis of their performance in a wide range of diagnostic categories provides guidelines for their judicious application. Where both are available, diagnostic catheterizations are either obviated or simplified.

Transesophageal echocardiographic in total anomalous pulmonary venous drainage: hypotension caused by compression of the pulmonary venous confluence during probe passage

Compression of vascular and airway structures can complicate transducer passage and manipulation during transesophageal echocardiography. This case describes hemodynamic compromise caused by compression of the posterior pulmonary venous confluence by a transesophageal echocardiography probe during intraoperative evaluation in an infant with supracardiac total anomalous pulmonary venous drainage. Careful hemodynamic and airway monitoring during transesophageal echocardiography is required in all patients, particularly during initial probe insertion and esophageal passage.

Echocardiographic assessment of adults with tetralogy of Fallot

Advances in medical and surgical management of congenital heart disease in the last three decades have resulted in a great many survivors to adulthood. Proper care requires intimate knowledge of the basic malformations and their surgical anatomy and results. Tetralogy of Fallot, the most common cyanotic malformation in adults, represents a spectrum from mild right ventricular outflow tract obstruction to complete pulmonary atresia. Evaluation of surgical residua and sequelae includes imaging of aortic-to-pulmonary arterial palliative shunts, detection of residual ventricular septal defect patch leaks or right ventricular outflow tract obstruction, definition of extracardiac conduit patency, and quantitation of ventricular function and valvular regurgitation. Refined echocardiographic imaging and hemodynamic definition is a mainstay in precise segmental anatomical and hemodynamic assessment. Transesophageal echocardiography is particularly important for intraoperative evaluation of surgical results.

Echocardiographic guidance during placement of the buttoned double-disk device for atrial septal defect closure

The usefulness of two-dimensional and Doppler echocardiography during buttoned double-disk device closure of an atrial septal defect was evaluated in 20 consecutive patients at the time of interventional catheterization. Transesophageal echocardiography was used in 11 patients (ages 5 to 62 years, weights 20 to 91 kg). Because of the size of the available transesophageal echo probe, transthoracic echocardiography was used in the remaining 9 patients (ages 4 to 5.5 years, weights 14 to 21 kg). In the transesophageal echo group, 1 patient was found to have no atrial septal defect despite a previous diagnosis by transthoracic echocardiography, 3 patients had atrial septal defects too large for closure despite attempts in 2, and 7 patients had transesophageal echo guided device placement. All of these 7 patients had small residual shunts by color Doppler, 2 had unusual arm positions, and 2 had surgical removal of the device due to embolization to the pulmonary artery in 1 and failure to obtain close approximation of the occluder and counteroccluder in 1. In the transthoracic echo group, 2 patients had atrial septal defects too large for closure, 1 patient had no femoral venous access, and 6 patients had transthoracic echo guided device placement. All of these 6 patients had small residual shunts by color Doppler and 3 of the 6 had unusual arm positions. For atrial septal defect sizing, transesophageal echo measurements correlated with catheter balloon size more closely than did transthoracic echo measurements (r 2 = 0.97 vs 0.86).(ABSTRACT TRUNCATED AT 250 WORDS)

Usefulness of biplane transesophageal echocardiography in neonates, infants and children with congenital heart disease

A study was performed to assess the feasibility, additional diagnostic value and potential applications of biplane transesophageal echocardiography in neonates, infants and children. One hundred thirty-two consecutive studies were attempted in 111 anesthetized children with congenital heart disease. Longitudinal and transverse planes were compared using 3 methods: (1) separate 7 mm longitudinal and transverse pediatric transducers used sequentially; (2) an experimental 9 x 8 mm biplane pediatric transducer; and (3) a standard adult biplane transducer (12 x 9 or 13 x 9 mm). In all but 1 patient, a probe could be inserted. The longitudinal plane provided superior visualization of both the right and left ventricular outflow tracts, the interatrial septum, the main pulmonary artery, the ascending aorta and the right coronary artery. In 18 patients (16%), the longitudinal plane provided completely new diagnostic information that was not obtained with combined transthoracic and transverse plane transesophageal echocardiography. However, the transverse plane was mandatory for demonstration of the 4-chamber view, short-axis cross sections through the great arteries, the distal right pulmonary artery and bifurcation of the left coronary artery. The longitudinal plane is complementary to the transverse plane, but cannot substitute for it.

Transesophageal echocardiography in adults with congenital cardiopathies

Eighty-seven adult patients with congenital cardiopathy were studied by using transesophageal echocardiography (TEE) over a period of 30 months. Transthoracic echocardiography was practiced on all patients, after which TEE with monoplanar and biplanar probes (74 and 15 patients, respectively) was used to confirm principal diagnoses and determine specific information. TEE findings were compared with those of cardiac catheterization in all 87 cases and with those of surgery in 15 cases. Dextrocardia was found in 11 cases and mesocardia in 2. Situs inversus was demonstrated in 6 and levoisomerism in 4. Intracardiac and extracardiac shunts were diagnosed in 20 cases, Ebstein's anomaly in 27, corrected transposition of great vessels in 15, univentricular atrioventricular connection in 7, cor triatriatum in 1, parachute mitral valve in 1, crisscross heart in 1, and double-outlet left atrium in 1. TEE was of particular value in evaluating total anomalous pulmonary venous connection, common atrioventricular canal, Ebstein's anomaly, corrected transposition of great vessels, and univentricular atrioventricular connection and in diagnosis of the rarer congenital cardiopathies.

Echocardiography in the management of single ventricle: fetal through adult life

Echocardiography contributes to the management of patients with single ventricle by providing an initial comprehensive evaluation in fetal and neonatal life. This allows planning of the initial surgical palliation, usually without the need for cardiac catheterization. Serial surveillance for problems such as subaortic stenosis, valvar insufficiency, or complications of the mitral palliation aids in planning for the timing and type of subsequent surgical procedures. Evaluation of single ventricle size, shape, and mass provides some indication of risk for a Fontan procedure. Transesophageal echocardiography provides an excellent window for the evaluation of the interatrial baffle for shunts, thrombi, or occlusion in the early postoperative period. Later, studies of ventricular and valve function help to direct medical management such as afterload reduction and diuretic therapy.

Outpatient transesophageal echocardiography with intravenous propofol anesthesia in children and adolescents

Outpatient transesophageal echocardiography (TEE) was performed in 10 children and adolescents (aged 3 to 19.5 years, mean 13.5 years; weight 12 to 91 kg, mean 49 kg), including two with Down's syndrome and one with autism, for diagnostic evaluation of issues unresolved by transthoracic echo examination (TTE). Issues for TEE: evaluation for atrial septal defect (two patients); anatomy of left ventricular outflow tract obstruction (one patient); aortic valve anatomy before valvuloplasty for insufficiency (one patient); evaluation for cause of cyanosis after Fontan operation (one patient); determination of source of high-velocity intracardiac turbulence after atrioventricular septal defect repair (one patient); rule out cardiac embolic source in patient with stroke (one patient); evaluate prosthetic valve function and rule out thrombus (one patient); determination of anatomic relationship of mitral valve to a ventricular septal defect before surgery for complex cyanotic heart disease (one patient); and evaluation for aortic dissection in Marfan's syndrome (one patient). Intravenous propofol anesthesia administered without endotracheal intubation by an anesthesiologist allowed successful outpatient TEE in nine patients; midazolam-conscious sedation was used in one. Outpatient TEE resolved diagnostic issues in all patients without complication, thereby avoiding cardiac catheterization in six patients and supplementing catheterization for preoperative planning in four patients. TEE can be performed safely and effectively with propofol anesthesia in the outpatient setting in carefully selected children and adolescents to provide vital diagnostic information. However, given the invasive nature of the procedure and the use of anesthesia, outpatient pediatric TEE should be used judiciously.

Postcardiotomy LVAD support and transesophageal echocardiography in a child

A case of postcardiotomy cardiogenic shock after repair of a congenital ventricular septal defect in a 5-year-old boy is reported. Mechanical circulatory support, instituted with a centrifugal left ventricular assist device, adequately supported the patient for 50 hours until recovery of native left ventricular function occurred. Transesophageal echocardiography proved to be useful in assessment of left ventricular function, allowing for timely institution and withdrawal of mechanical circulatory support.

Transgastric imaging: a valuable addition to the assessment of congenital heart disease by transverse plane transesophageal echocardiography

Multiview transgastric imaging was performed with standard single transverse plane transesophageal probes in 16 patients to assess its potential additional value in defining the complexities of congenital heart disease. The age of patients studied ranged from 1.1 to 32 years (mean of 10.4 years). Their body weight ranged from 8.3 kg to 69 kg (mean of 29 kg). In all studies, a complete range of transesophageal and transgastric views could be obtained. The information thus obtained was correlated with the findings of prior precordial echocardiography and subsequent cardiac catheterization or surgical inspection. The pathologic conditions studied included tetralogy of Fallot, (4), isolated ventricular septal defect (4), valvular aortic stenosis (1), subvalvular and valvular aortic stenosis (1), supraaortic stenosis (1), total atrioventricular septal defect (1), secundum atrial septal defect (1), double-outlet right ventricle (1), double-chambered right ventricle (1), and pulmonary atresia, ventricular septal defect, and superoinferior ventricles (1). The single-plane data provided by transgastric scanning were compared and contrasted with that obtained from transesophageal scanning. Transgastric views were shown to be superior to transesophageal imaging in demonstrating the anatomy of the right ventricular outflow tract, the left ventricular outflow tract, and the apical and anterior aspects of the ventricular septum. In addition, these views offered a favorable angle of incidence for spectral wave Doppler studies of flow in both outflow tracts. We conclude that transverse plane transgastric imaging is an important addition to the transesophageal assessment of congenital cardiac disease. Its main additional benefit is in the study of lesions that involve either the right or left ventricular outflow tract or the anteroapical ventricular septum. Its main clinical value is likely to be in the evaluation of the perioperative patient in whom diagnostic precordial imaging is frequently impossible.

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, multiplanar, multifrequency 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.

Transesophageal echocardiography and the intraoperative management of pediatric congenital heart disease: initial experience with a pediatric esophageal 2D color flow echocardiographic probe

Intraoperative color Doppler transesophageal echocardiography (TEE) was performed in 26 patients undergoing corrective or palliative surgery for congenital heart disease. Age ranged from 1 day to 15 years, and body weight ranged from 2.9 to 42 kg. Objectives of the study were to determine the smallest infant in whom the pediatric probe could be used safely, additional diagnostic value, and it role in the intraoperative assessment of the surgical repair. The insertion of the pediatric probe was possible in all 26 patients. The smallest infant in this series was a newborn weighing 2.9 kg. Excellent correlation was obtained with preoperative transthoracic echocardiographic findings and operative findings. Assessment of the surgical repair was obtained in the immediate postcardiopulmonary bypass period. No short-term complications occurred in this series. Intraoperative color Doppler TEE provided a detailed and accurate assessment of the morphology, the function of the heart, and altered the management of at least two patients.