3-D echocardiography: new developments and future prospects

Due to limitations in transthoracic and occasionally transesophageal 2-D echocardiography with respect to volumetric analysis and morphologic and functional assessment in patients with congenital malformations and valvular heart disease, additional diagnostic tools have been established. In parallel with the rapid evolution in computer technology, 3-D echocardiography has grown into a well-developed technique, such as volume-rendered 3-D reconstruction, capable of displaying dynamic morphology depicting depth of the structures, their attachment, and spatial relation to the surrounding tissue. Nevertheless, the complexity of data acquisition and data processing required for adequate dynamic 3-D echocardiographic imaging and volumetric analysis does not allow to use this approach routinely. The commonly used dynamic 3-D echocardiography means off-line computer-assisted image reconstruction from a series of cross-sectional echocardiographic images using currently available transesophageal and transthoracic transducers. Alternatively, real-time 3-D echocardiography based on novel matrix, phased-array transducer technology has been introduced. Although this technique can be easily combined with any routine examination, its clinical use is limited because of a lower image quality in comparison with dynamic 3-D echocardiography. Up to now, there is no transesophageal approach available using real-time 3-D echocardiography. Recently, dynamic 3-D echocardiographic technique has matured noticeably. Beside the well-known sequential scanning, which is characterized by a fixed probe and patient in space and predetermined motion of the transducer, the freehand scanning using an electromagnetic location system has found its way to clinical environment. The main advantage of this technique is that the transducer can be freely moved by the examiner and, thus, the data set acquired within a routine examination. Also 3-D rendering and display have been developed further. In this respect, especially the "real-time rendering mode" allowing the reconstructed 3-D image to be animated and moved in space and to look at it from different perspectives has gained increasing acceptance. In valvular heart disease, reconstructive surgical treatment is aspired. 3-D echocardiographic imaging is the only technique providing "surgical views" prior to opening the heart. It is capable of distinguishing particular destructive substructures of the valves and the valvular apparatus. Especially in mitral valvular reconstruction, it is of clinical importance to achieve optimal surgical results. With respect to volumetric and mass analysis, 3-D echocardiography is more accurate and reproducible in comparison with conventional 2-D analysis. It provides data independent of geometric assumptions, what may considerably influence the results in the presence of wall motion abnormalities, especially in aneurysmatic ventricles. Volumetric analysis of the aneurysmal portion may also be helpful prior to surgical resection. 3-D echocardiography can also be recommended as a valuable additional approach to atrial septal defect (ASD), corrected transposition of the great arteries, cor triatriatum, and, within limits, to ventricular septal defect (VSD) as well. Especially with respect to ASD and VSD, the potential significance of 3-D echocardiography prior to device closure is emphasized. At present, its additional information in decision-making and the increasing number of clinical cases that can be addressed and answered already justify the clinical use of this technique.     

Comparison of left ventricular volumes and ejection fractions measured by three-dimensional echocardiography versus by two-dimensional echocardiography and cardiac magnetic resonance in patients with various cardiomyopathies

End-diastolic volume and end-systolic volume were measured in 35 consecutive patients with cardiomyopathy using 2-dimensional (2-D) and 3-dimensional (3-D) echocardiography (2, 4, and 8 planes) and cardiac magnetic resonance imaging. Three-dimensional echocardiography correlates better with magnetic resonance imaging than does 2-D echocardiography. Its accuracy improves with the increase in the number of planes used. Two-dimensional echocardiography underestimates volumes, mainly in the subgroup with an ejection fraction of <50%, whereas 3-D echocardiography does not, if enough planes are used. However, in patients with an end-diastolic volume > or =150 ml, the underestimation of 3-D echocardiography is statistically significant. Increasing the number of planes to 8 reduces this bias. Conversely, patients with an end-diastolic volume <150 ml are accurately studied with just 4 planes.     

Quantitative assessment of aortic stenosis by three-dimensional anyplane and three-dimensional volume-rendered echocardiography

Aortic stenosis is a challenge for three-dimensional (3-D) echocardiographic image resolution. This is the first study evaluating both 3-D anyplane and 3-D volume-rendered echocardiography in the quantification of aortic stenosis. In 31 patients, 3-D echocardiography was performed using a multiplane transesophageal probe. Within the acquired volume dataset, five parallel cross sections were generated through the aortic valve. Subsequently, volume-rendered images of the five cross sections were reconstructed. The smallest orifice areas of both series were compared with the results obtained by two-dimensional (2-D) transesophageal planimetry and those calculated by Doppler continuity equation. No significant differences were found between Doppler (0.76 +/- 0.18 cm(2)), 2-D echocardiography (0.78 +/- 0.24 cm(2)), and 3-D anyplane echocardiography (0.72 +/- 0.29 cm(2)). The orifice area measured smaller (0.54 =/- 0.31 cm(2), P < 0.001) by 3-D volume-rendered echocardiography. Bland-Altmann analysis indicated that for 3-D anyplane echocardiography, the mean difference from Doppler and 2-D echocardiography was - 0.04 +/- 0.24 cm(2) and - 0.06 +/- 0.23 cm(2), respectively. For 3-D volume-rendered echocardiography, the mean difference was -0.23 +/- 0.24 cm(2) and - 0.25 +/- 0.26 cm(2), respectively. In the subgroup with good resolution in the 3-D dataset, close limits of agreement were obtained between 3-D echocardiography and each of the reference methods, while the subgroup with poor resolution showed wide limits of agreement. In conclusion, planimetry of the stenotic aortic orifice by 3-D volume-rendered echocardiography is feasible but tends to underestimate the orifice area. Three-dimensional anyplane echocardiography shows better agreement with the reference methods. Accuracy is influenced strongly by the structural resolution of the stenotic orifice in the 3-D dataset.     

Feasibility and utility of three-dimensional color flow echocardiography of the aortic arch: The "echocardiographic angiogram"

Two-dimensional transthoracic echocardiography (2DE) is the most commonly used diagnostic modality to evaluate congenital and acquired abnormalities of the aortic arch. However, 2DE is frequently limited in this ability due to the three-dimensional character of the arch and its interrelationships with other vascular structures. Recently, three-dimensional echocardiography (3DE) with 3D color flow Doppler became commercially available. We examined the feasibility and utility of 3DE with 3D color Doppler in the evaluation of patients with congenital (native and postoperative) abnormalities of the aortic arch. We found that 3DE color flow provides important diagnostic information in patients with aortic arch anomalies, in a manner that is quick and user-friendly. In addition, 17 of the 26 patients had their 3DE findings confirmed by additional modalities, providing reasonably significant validation for our findings with 3DE.     

Three-Dimensional Echocardiography of Right Heart Pathology

Three-dimensional (3-D) echocardiography uses sequentially acquired tomography echocardiographic data, which is gated to the cardiac cycle, to reconstruct 3-D views of the heart. So far, this technique has been used primarily to evaluate left-sided heart structures. This report focuses on congenital and acquired right-sided heart pathologies that have been visualized by 3-D echocardiography. In addition to reviewing the literature, several representative figures are included illustrating the unique ability of 3-D echo to elucidate complex right heart anatomy. After a brief introduction to the technical aspects of 3-D echocardiography, the discussion centers on evaluation of congenital heart disease and right-sided masses, determination of right ventricular mass and volume, and evaluation of right-sided valvular heart disease. Congenital heart diseases that are reviewed include atrial septal defect (location, size, efficacy of repair), ventricular septal defect, and congenital heart disease in the fetus being evaluated in utero. Evaluation of right-sided masses, including tumors, vegetations, and thrombi, is reviewed. Methods of determining right ventricular volume and mass using 3-D echo are discussed. Evaluation of valvular heart disease, including Doppler analysis of regurgitant flow, is examined. Finally, special attention is given to the perioperative and intraoperative use of 3-D echocardiography for patients with these conditions. The conclusion summarizes the current and potential future uses of 3-D echocardiography.     

Cardiac magnetic resonance imaging for accurate diagnosis of aortic arch anomalies in patients with 22q11.2 deletion

This study demonstrates, in patients with 22q11.2 deletion, the wide variety of complex aortic arch anomalies that can be accurately defined by cardiac magnetic resonance imaging (MRI) compared with echocardiography. From May 1999 to August 2003, 17 of 68 patients (25%) with 22q11.2 deletion referred for cardiac evaluation required cardiac MRI, after echocardiography, to clarify aortic arch anatomy. Images of cardiac anatomy were obtained using steady-state free precession, half-Fourier acquired single turbo spin-echo dark blood sequences and gadolinium for 3-dimensional reconstruction. All MRI findings were abnormal, and in 16 of 17 cases, echocardiography was unable to define aortic arch anomalies correctly compared with MRI.     

Rapid and accurate quantification of right ventricular volume and stroke volume by real-time 3-dimensional triplane echocardiography

BACKGROUND: Previous studies have demonstrated that 3-Dimensional (3-D) echocardiography can determine right ventricular (RV) volume accurately. However, this technique has not been feasible in everyday clinical practice because of the necessity of time-consuming off-line processes. HYPOTHESIS: A newly developed real-time 3-D triplane echocardiography, which acquires 3 apical rotational cross-sectional images simultaneously, holds the promise to resolve these problems. METHODS AND RESULTS: Sixteen excised formalin fixed porcine hearts and 24 healthy human subjects underwent real-time 3-D triplane echocardiography. In an anatomic in vitro study, the actual volume of RV was obtained by spilling water in the RV cavity into a graduated cylinder for measurement, which served as a reference standard for comparison. For healthy subjects, the RV stroke volume (SV) was measured by triplane echocardiography which was compared with the left ventricular (LV) SV obtained by conventional 2-Dimensional echocardiography (2-DE). Excellent correlation and agreement between 3-D triplane imaging derived RV volume and the actual one for excised porcine hearts were observed (r = 0.979, p < 0.001, mean difference 2.2 mL). In healthy human subjects, good correlation and agreement between 3-D triplane imaging derived RV SV and LV SV measured by 2-DE were obtained (r = 0.970, p < 0.001, mean difference 5.9 mL). CONCLUSIONS: Real-time 3-D triplane echocardiography provides us a new method for rapid and accurate quantification of RV volume. Furthermore, this new method holds the promise for evaluating RV volume and SV in routine clinical practice. Copyright (c) 2008 Wiley Periodicals, Inc.     

Real-time three-dimensional echocardiography in assessment of heart disease

Echocardiography has progressed at an impressive pace in the last decade. A plethora of new techniques, including tissue-Doppler imaging, harmonic imaging, contrast echocardiography, digital-stress echocardiography, and three-dimensional (3-D) echocardiography, have altered our diagnostic strategies for managing patients with heart disease. Until recently, 3-D echocardiography was looked upon as a time-consuming and tedious procedure, making it more a research interest than a diagnostic tool. The introduction of real-time three-dimensional (RT-3-D) echocardiography has made possible dynamic diagnostic/therapeutic assessments while the procedure is performed. At The University of Texas Medical Branch in Galveston, Texas, our more than 2 years of experience with RT-3-D suggests that this technique will play an important role in diagnosing and managing patients with heart disease.     

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.     

A novel approach to produce axial echocardiographic images by three-dimensional transesophageal echocardiography: A step-by-step guide

Three-Dimensional (3-D) echocardiography is becoming increasingly used to diagnose and describe the spatial location of valvular pathologies and atrial septal defects during transesophageal echocardiography (TEE). The role of 3D-TEE is not well established in diagnosing other congenital heart diseases like partial anomalous pulmonary venous drainage (PAPVD) and coronary anomalous. We propose a step by step approach to producing computed tomography-simulated axial images from 3-D TEE to simplify TEE interpretation and diagnosis of cardiac abnormalities.     

Two-dimensional echocardiographic assessment of the aorta in infants and children with congenital heart disease

To determine the accuracy of two-dimensional echocardiography in the identification of congenital anomalies of the aorta, we compared two-dimensional echocardiographic with angiographic results in 261 consecutive infants and children with congenital heart disease (age 1 day to 20 years, mean 3.3 years). Two-dimensional echocardiography was performed and interpreted without knowledge of angiographic results. Complete visualization of the ascending and descending aorta and aortic arch branches was possible by two-dimensional echocardiographic examination in suprasternal, parasternal, and subcostal views of 255 patients (98%). Identification of the esophagus during swallowing aided the diagnosis of anatomic characteristics of aortic arch. One or more significant aortic arch anomalies were present on angiograms of 116 of 255 patients (46%) and were detected by two-dimensional echocardiography in 110 (sensitivity 95%, 99% specificity). Anomalies detected by two-dimensional echocardiography/angiography were ascending aorta hypoplasia in four/four, truncus arteriosus three/three, right aortic arch 31/31, anomalous subclavian artery 11/16, coarctation 27/29, and patent ductus arteriosus 53/57. We conclude that two-dimensional echocardiography can be used to determine the anatomy of the aorta in most infants and children. In selected patients, two-dimensional echocardiography may eliminate the need for angiographic examination before surgery for congenital heart disease.     

Three-dimensional echocardiographic determination of cardiac output at rest and under dobutamine stress: comparison with thermodilution measurements in the ischemic pig model

Determination of cardiac output is a potentially important clinical application of three-dimensional (3-D) echocardiography since it could replace invasive measurements with the Swan-Ganz-catheter. To date, there are no studies available to determine whether cardiac output measured by thermodilution can be predicted reliably under changing hemodynamic conditions. Fifteen pigs with ischemic myocardium were examined under four hemodynamic conditions at rest and under pharmacological stress with 5, 10, and 20 microg/kg/min dobutamine. The 3-D datasets were recorded by means of transesophageal echocardiography. The endocardial definition was enhanced by administering the contrast agent FS069 (Optison). Cardiac output was calculated as the product of stroke volume (end-diastolic - end-systolic volume) and heart rate. The invasive measurements were performed with a continuous thermodilution system. In general, there was moderate correlation between 3-D echocardiography and thermodilution(r = 0.72, P < 0.001). At rest, the 3-D echocardiographic measurements were slightly but significantly lower than the invasive measurements (mean difference 0.6 +/- 0.5L/min,P < 0.001). Under stress with 5, 10, and 20 microg/kg/min dobutamine, there was a marked increase in the deviation (1.3 +/- 0.5L/min,P < 0.001; 1.6 +/- 0.7 L/min,P < 0.001; and 2.1 +/- 1.1L/min,P < 0.001, respectively). The deviation was based on two factors: (1). Under stress, the decreasing number of frames per cardiac cycle acquired with 3-D echocardiography led to imprecise recording of end-diastolic and end-systolic volumes, and thus to an underestimation of cardiac output. At least 30 frames per cardiac cycle are needed to eliminate this effect. (2). There is a systematic difference between 3-D echocardiographic and invasive measurements, which is independent of the imaging rate. This is based on an overestimation of the true values by thermodilution. In conclusion, cardiac output can be determined correctly by 3-D echocardiography for normal heart rates at rest. At elevated heart rates, the temporal resolution of 3-D systems currently available is not adequate for reliable determination. In performing and evaluating future clinical comparative studies, the systematic difference between 3-D echocardiography and thermodilution, based on overestimation by thermodilution, must be taken into account.     

Improved assessment of mitral valve stenosis by volumetric real-time three-dimensional echocardiography

OBJECTIVES: This study was performed to determine the feasibility, accuracy and reproducibility of real-time volumetric three-dimensional echocardiography (3-D echo) for the estimation of mitral valve area in patients with mitral valve stenosis. BACKGROUND: Planimetry of the mitral valve area (MVA) by two-dimensional echocardiography (2-D echo) requires a favorable parasternal acoustic window and depends on operator skill. Transthoracic volumetric 3-D echo allows reconstruction of multiple 2-D planes in any desired orientation and is not limited to parasternal acquisition, and could thus enhance the accuracy and feasibility of calculating MVA. METHODS: In 48 patients with mitral stenosis (40 women; mean age 61 +/- 13 years) MVA was determined by planimetry using volumetric 3-D echo and compared with measurements obtained by 2-D echo and Doppler pressure half-time (PHT). All measurements were performed by two independent observers. Volumetric data were acquired from an apical view. RESULTS: Although 2-D echo allowed planimetry of the mitral valve in 43 of 48 patients (89%), calculation of the MVA was possible in all patients when 3-D echo was used. Mitral valve area by 3-D echo correlated well with MVA by 2-D echo (r = 0.93, mean difference, 0.09 +/- 0.14 cm2) and by PHT (r = 0.87, mean difference, 0.16 +/- 0.19 cm2). Interobserver variability was significantly less for 3-D echo than for 2-D echo (SD 0.08cm2 versus SD 0.23cm2, p < 0.001). Furthermore, it was much easier and faster to define the image plane with the smallest orifice area when 3-D echo was used. CONCLUSIONS: Transthoracic real-time volumetric 3-D echo provides accurate and highly reproducible measurements of mitral valve area and can easily be performed from an apical approach.     

The value of 2-D Doppler echocardiography in the evaluation of asymptomatic patients with Mustard operation for transposition of the great arteries.

2-D Doppler echocardiography was used to assess the occurrence of haemodynamic abnormalities in 45 asymptomatic patients, aged 4 to 16 years (median 7.4) after a Mustard operation for transposition of the great arteries. The findings were compared with those derived from cardiac catheterization. Thirty-five cardiac lesions were correctly diagnosed by 2-D Doppler echocardiography in 23 patients, but on six occasions, minor abnormalities were missed. 2-D Doppler echocardiography demonstrated systemic venous pathway obstruction of more than 3 mmHg at cardiac catheterization in nine patients, and in five of the six patients with pulmonary venous channel obstruction. A left ventricular outflow tract obstruction (pressure difference greater than 15 mmHg) was diagnosed correctly by Doppler echocardiography in seven patients. Baffle leakage was found in two patients with a left to right shunt of 25% or more of pulmonary blood flow, but was missed in five out of nine patients with small shunts. Tricuspid regurgitation was well defined in eight patients. The absence of symptoms and a routine examination after a Mustard operation do not rule out haemodynamic abnormalities. However, these, with the possible exception of minor baffle leakage, can be detected by 2-D Doppler echocardiography.     

Postmortem echocardiography and tomographic anatomy of hypoplastic left heart syndrome after palliative surgery

A study was undertaken to improve the understanding of the 3-dimensional (3-D) topology of a complex surgical reconstruction. The pathologic anatomy was investigated by first fixing postmortem heart specimens in such a way as to preserve the 3-D relations. Next, a technique for postmortem 2-D echocardiography was developed to aid in selection of tomographic planes for sectioning the specimens. Subsequent adjustment of planes of section was made to better show particular facets of the anatomy. The material for this investigation was drawn from cases of hypoplastic left heart syndrome after surgical palliation by the Norwood procedure. Three potential hemodynamic sequelae—restrictive inter atrial communication, aortic obstruction at any level and distortion of the pulmonary artery confluence—served as the anatomic focus for this study. Careful preservation of 3-D topology and postmortem 2-D echocardiographic imaging coupled with tomographic sectioning of specimens led to development of new, clinically relevant echocardiographic views for imaging specific atrial septal and aortic arch anomalies. These techniques offer insight into the spectrum of anatomic sequelae of this type of surgery and may be applied to echocardiographic imaging of patients and refinement of surgical technique for other forms of complex congenital heart disease.     

Real-time, three-dimensional localization of a Brockenbrough needle during transseptal catheterization using a nonfluoroscopic mapping system

We describe a new technique that allows real-time, three-dimensional (3-D) localization of the Brockenbrough needle tip during transseptal catheterization using the EnSite NavX system. Transseptal catheterization has been traditionally performed using fluoroscopy, and recently, with the use of intracardiac echocardiography. However, even intracardiac echocardiography has the limitation of providing only 2-D views limited to the ultrasound plane. By displaying the transseptal needle on the EnSite NavX system, we achieved real-time 3-D localization of the needle tip within the right atrial geometry and found accurate visual correlation between fluoroscopy, intracardiac echocardiography and nonfluoroscopic 3-D cardiac mapping. This study suggests that the EnSite NavX system is able to provide 3-D localization of the transseptal needle during transseptal catheterization, and may be a useful imaging modality in this procedure.     

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.     

Accuracy of two-dimensional echocardiography in the diagnosis of congenital heart disease

To assess the accuracy of 2-dimensional (2-D) echocardiography in the evaluation of cardiac anatomy in patients with congenital heart disease, 2-D echocardiograms were performed in 126 infants and children before cardiac catheterization and angiocardiography. The segmental echocardiographic analysis included determination of intracardiac, great artery, systemic venous and pulmonary venous anatomy. The 126 patients had 259 separate cardiovascular abnormalities, of which 226 (87%) were prospectively identified by 2-D echocardiography. There were 8 false-positive diagnoses. The most common lesions and the sensitivity and specificity of echocardiography were: patent ductus arteriosus, 41 patients (83% and 100%, respectively), ventricular septal defect, 35 patients (86% and 100%); atrial septal defect, 26 patients (85% and 99%); pulmonary valve stenosis, 25 patients (77% and 97%), transposition of the great arteries, 16 patients (100% and 100%); and total anomalous pulmonary venous connection, 14 patients (85% and 100%). Less common defects and their rate of detection included coarctation of the aorta, 10 of 12 patients; atrioventricular canal, 10 of 10 patients; tetralogy of Fallot, 10 of 10 patients; aortic valve stenosis 8 of 8 patients; right aortic arch, 8 of 8 patients; interrupted aortic arch, 4 of 4 patients; and unilateral pulmonary vein atresia, 0 of 1 patient. In 33 patients (26%), the errors in echocardiographic analysis were judged to have surgical importance. Most errors were the result of overlooking or misinterpreting data that had been appropriately recorded on videotape. Pulmonary valve stenosis and patent ductus arteriosus are the lesions most likely to be misdiagnosed by ultrasound studies relying on imaging alone.