Detection of ostium secundum atrial septal defects by transoesophageal cross-sectional echocardiography

Agitated Saline Contrast Echocardiography in the Identification of Intra- and Extracardiac Shunts: Connecting the Dots

Agitated saline contrast studies are an essential component of contemporary echocardiography. Agitated saline contrast plays a critical role in the elucidation of intracardiac versus intrapulmonary shunting and can have major therapeutic implications, particularly in light of the evolution of percutaneous treatment options for atrial septal defects or a patent foramen ovale. Despite their perceived simplicity, however, there are numerous pitfalls of these investigations that can occur during their performance and interpretation. As such, the authors review the "bubble study" in identifying intracardiac and extracardiac shunts, including the history of its development, the physics and physiology of contrast enhancement, how to optimally perform and interpret an agitated saline contrast study, and its safety in unique populations.

Point-of-care echocardiography for the evaluation of right-to-left cardiopulmonary shunts: a narrative review

Right-to-left pulmonary and cardiac shunts (RLS) are important causes of refractory hypoxia in the critically-ill perioperative patient. Using a point-of-care ultrasound (POCUS) agitated saline bubble study for an early diagnosis allows patients with clinically significant RLSs to receive expedited therapy. This narrative review discusses the principles of agitated saline ultrasonography as well as the role of POCUS in detecting the most common RLS types seen in the intensive care unit, including patent foramen ovale, atrial septal defects, and pulmonary arterio-venous malformations. An illustrated discussion of the procedure, as well as shunt-enhancing maneuvers (Valsalva or lung recruitment maneuver with subsequent rapid release) is provided. With the wide dissemination of bedside ultrasound within the perioperative and critical care arena, POCUS practitioners should be knowledgeable of the potential pitfalls leading to both false-positive and false-negative studies. False-positive studies may be due to congenital abnormalities, mischaracterization of intrapulmonary shunts as intracardiac shunts (and vice versa), or evidence of the Valsalva effect. False negatives are typically due to respiratory-phasic variation, performing an inadequate shunt-enhancing maneuver, inadequate injection of agitated saline, or pathophysiologic states of elevated left atrial pressure. Finally, alternative POCUS methods for determining presence of an RLS in patients with poor echocardiographic windows are discussed, with a focus on pulsed-wave Doppler interrogation of arterial signals.

Right bundle branch block as a marker for interatrial septal abnormalities

BACKGROUND

Interatrial septal anomalies, which include atrial septal defect, patent foramen ovale, and atrial septal aneurysm, are common disorders among adult patients. Early detection of interatrial septal anomalies is important in order to prevent haemodynamic consequences and/or thromboembolic events. Electrocardiogram offers some clues that should serve as hints for detection of interatrial abnormalities. The aim of our study was to analyse the interatrial septum by transoesophageal echocardiography in patients with electrocardiogram signs of right bundle branch block and in those without right bundle branch block.

METHODS AND RESULTS

In a prospective study, 87 adult patients were included, that is, 41 with electrocardiogram signs of right bundle branch block forming the first group and 46 without right bundle branch block forming the second group. Interatrial septal anomalies were present in 80.5% of the patients with right bundle branch block, with patent foramen ovale (39.02%) being the most prevalent disorder, followed by atrial septal aneurysm (21.9%) and atrial septal defect (19.5%). Interatrial septal abnormalities were significantly more frequent in the first group compared with the second group (80.5% versus 6.5%, p value less than 0.001). Independently, patent foramen ovale was significantly more prevalent in patients with right bundle branch block (39.02% versus 4.3%, p value less than 0.001), as were atrial septal aneurysm (21.9% versus 2.2%, p value equal 0.01) and atrial septal defect (19.5% versus 0%, p value equal 0.004).

CONCLUSIONS

Right bundle branch block should serve as a valuable indicator to motivate a detailed search for interatrial septal abnormalities.

Usefulness of the right parasternal approach to evaluate the morphology of atrial septal defect for transcatheter closure using two-dimensional and three-dimensional transthoracic echocardiography

BACKGROUND

The aim of this study was to demonstrate the feasibility and usefulness of addition of the right parasternal approach to the conventional left parasternal and apical approaches using two-dimensional (2D) and three-dimensional (3D) transthoracic echocardiography (TTE) for morphologic evaluation in cases of transcatheter closure of atrial septal defects (ASDs).

METHODS

In 112 consecutive patients with ASDs, the morphology of the defects was evaluated for transcatheter closure in the right parasternal view in addition to the conventional left views using 2D and 3D TTE. Measurements of the maximal ASD diameter and detection of deficient rim obtained on 2D TTE were compared with those obtained by 2D transesophageal echocardiography. The shapes and locations of ASDs visualized by 3D TTE were compared with those visualized by 3D transesophageal echocardiography.

RESULTS

In 88 patients (80.0%), optimal images from the right parasternal approach for morphologic evaluation of ASDs were obtained. Although there was a significant difference in maximal ASD diameter obtained only in the conventional left approach compared with transesophageal echocardiographic measurements (P < .05), when the right parasternal approach was applied, a significant difference was not found (P = .18), and the diagnostic concordance of the rim deficiency was improved from 85.2% to 90.9%. Three-dimensional TTE from the right parasternal approach improved visualization of the shape and location of ASDs from 65.5% to 74.5%.

CONCLUSIONS

Additional use of the right parasternal approach enables detailed morphologic evaluation for transcatheter closure of ASDs. In patients with suboptimal images on 3D TTE in the left conventional approach, additional 3D TTE in the right parasternal approach can improve the feasibility of obtaining optimal 3D images to evaluate the shapes and locations of ASDs.

Three-dimensional trans-esophageal Echocardiographic Evaluation of Atrial Septal Defects: A Pictorial Essay

This pictorial assay illustrates the methodology of evaluating the atrial septal defects by three dimensional transesophageal echocardiography with the help of representative images. The article starts by discussing the technical details of how to acquire and crop the dataset to reconstruct the transesophageal three dimensional echocardiographic images of the inter atrial septum. Next, the anatomical details of the normal inter atrial septum are illustrated, followed by representative examples of all the possible defects of inter atrial septum. All the images have been reproduced in a uniform pattern which is similar to the view of the inter atrial septum that is seen in the real life situation by the surgeon.

Atrial septal aneurysm associated with additional cardiovascular comorbidities in two middle age female patients with ECG signs of right bundle branch block: two case reports

Introduction

Atrial septal aneurysm (ASA) is often associated with other atrial septal abnormalities, particularly with atrial septal defect type ostium secundum or patent foramen ovale. ECG signs of incomplete or complete right bundle branch block are known to be associated with atrial septal defects, however such correlation with other atrial septal abnormalities is not documented.

Case presentations

We report here two cases of middle age female patients that presented with dyspnea on physical effort, right bundle branch block (RBBB) on ECG and ASA combined with other cardiac disorders. Transesophageal echocardiography revealed additional information to the ones obtained by surface echocardiography, in both cases.

Conclusion

ASA associated with RBBB on ECG may serve as a hint for the presence of additional cardiac abnormalities, thus rousing the demand for a detailed cardiac investigation.

Surgical validation and implications for transcatheter closure of quantitative echocardiographic evaluation of atrial septal defect

Accurate evaluation of secundum atrial septal defect (ASD) is important for the success of transcatheter closure. The purpose of this study was (1) to describe a quantitative evaluation by transthoracic (TTE) and transesophageal (TEE) echocardiography of the various morphologic features of ASD that might be important for patient selection for transcatheter closure, and (2) to assess the reliability of these 2 methods by surgical findings. Preoperative TTE and TEE were used to evaluate the ASD of 27 children undergoing surgical closure. Measurements included the diameters of ASD and the atrial septal lengths in the transverse and longitudinal axis, and the width of the superior, inferior, anteroinferior, and posterior septal margins. The shape and location of the ASD and the adequacy of the septal margins for anchoring occluding devices were determined. Echocardiographic data were compared with corresponding surgical measurements. No significant difference occurred in the means of all the parameters measured with the 3 methods, except for the transverse ASD diameter (p <0.05). Good agreement occurred between TTE and TEE and surgical data, except for the transverse ASD diameter, transverse atrial septal length, and the posterior septal margin on TTE. Intraclass correlations between TTE and TEE and surgical measurements of all parameters were good, except for the transverse ASD diameter. The accuracy in determining shape and location of the ASD by TTE and TEE were 100%, whereas that for determining the adequacy of septal margins was 98% and 97%, respectively. In conclusion, TTE and TEE are reliable methods for quantitative evaluation of ASD.

[Echocardiographic evaluation in unoperated congenital heart disease in adults]

Echo and Doppler echocardiographic procedures have gained special importance in the diagnostics of congenital diseases in adults. These procedures permit detailed visualization of the pathomorphology of the heart as well as reliable evaluation of the hemodynamic changes. There are differentiated indications for the various procedures, such as transthoracic and transesophageal echocardiography, Doppler and color-Doppler echocardiography, contrast echocardiography and 3-dimensional echocardiography. This article discusses the opposition of the various echo and Doppler echocardiographic procedures with respect to the diagnostics of the most frequent non-operated congenital diseases in adults. The pathomorphology of the various congenital diseases will be summarized and then the important echocardiographic criteria presented which are decisive for the diagnostic procedure. In simple congenital malformation of cardiac valves, such as bicuspid aortic valve (Figure 1: aortic ring abscess), pulmonary valve stenosis (Figure 2), Ebstein's anomaly (Figure 3) or malformations of the mitral valve (Figure 4: cleft in the anterior mitral cusp), the diagnosis can often be made using transthoracic echo and Doppler echocardiography, and the severity of the defect determined. However, the sonographic conditions, especially in adults, are frequently too limited to permit recognition of detailed smaller changes, so that transesophageal examination is required to finally confirm the diagnosis in these patients. In the diagnostics of diseases of the left ventricular outflow tract and the thoracic aorta, such as subvalvular aortic valve stenosis (Figure 5), the sinus of Valsalva aneurysm or the coarctation of the aorta (Figure 6), the left ventricular outflow tract can be evaluated morphologically from a transthoracic procedure and the accelerations of flow can be recorded by continuous wave Doppler. If there is no sclerosis of the fibrous membrane, these can often not be depicted by transthoracic procedures, so that a supplementary transesophageal examination is meaningful. This is required in any case for diseases of the descending thoracic aorta. In the case of congenital lesions, such as atrial septal defects (Figure 7: anomalous pulmonary venous return, Figure 8: 3-dimensional visualization of an atrial septal defect, Figure 9: sinus venosus defect), ventricular septal defect or a patent ductus arteriosus Botalli (Figure 10), color-Doppler and contrast echocardiography have become especially important. Transesophageal examination is also indicated for these congenital diseases for direct depiction of the defect as well as for precise evaluation of the shunt. Moreover, in atrial septal defects, it has been shown that a 3-dimensional echocardiography provides additional advantage with respect to spatial relationship of the defect to the other cardiac structures, as well as presenting dynamic changes during a heart cycle. Extensive knowledge of complex congenital heart disease, such as tetralogy of Fallot (Figure 11), complete transposition of the great arteries, congenitally corrected transposition of the great arteries (Figure 12), the double-outlet right ventricle, truncus arteriosus communis, the cor triatriatum, tricuspid atresia (Figure 13) or the univentricular heart (Figure 14) usually requires performance of a transthoracic echo- and Doppler echocardiographic examination to assess the pathomorphological changes and to examine hemodynamics. In the majority of patients, supplementary transesophageal echocardiography and an echo contrast examination are important. Initial examinations using 3-dimensional echocardiography are very promising in this connection and with respect to the exact spatial presentation of pathoanatomical structures.

Secundum atrial septal defect is a dynamic three-dimensional entity

BACKGROUND

The aim of this study was to evaluate the diagnostic relevance of 3-dimensional (3D) echocardiography in the assessment of secundum atrial septum defect (ASD2).

METHODS AND RESULTS

Twenty-three patients (age 2 to 58 years) with an ASD2 were studied by transthoracic (n = 9) or transesophageal (n = 14) echocardiography for the acquisition of a 3D data set before undergoing surgical repair. Qualitative (location, shape, and structure) and quantitative (largest and smallest anteroposterior and superoinferior diameters) characteristics were analyzed and compared with surgical findings. Intraobserver and interobserver variability were assessed. The gross anatomy of the ASD2, shown by the 3D images, was confirmed by the surgeon in 21 of 23 patients, but the presence of membranous or fenestrated remnants of the valvula foramina ovalis in the defect was not optimally visualized in 7 patients. Three-dimensional echocardiography revealed changes in diameter and shape of the ASD2 during the cardiac cycle. The measured largest and smallest anteroposterior diameters and their intraobserver and interobserver agreement were 274 +/- 12 mm, r = 0. 95 (P <.001), r = 0.92 (P <.001), and 194 +/- 9 mm, r = 0.96 (P <. 001), r = 0.94 (P <.001), respectively. The measured largest and smallest superoinferior diameter and their intraobserver and interobserver agreement were 304 +/- 26 mm, r = 0.90 (P <.001), r = 0.97 (P <.001), and 204 +/- 10 mm, r = 0.83 (P <.001), r = 0.84 ( P <.001), respectively. The correlation coefficient between 2D and 3D echocardiography for the largest anteroposterior and superoinferior diameter was r = 0.69 (P <.001) and r = 0.68 (P =.05), respectively. The correlation coefficient between the measurements from 3D reconstructions and direct surgical measurements was r = 0.20 (P = not significant) and r = 0.57 (P <.05), whereas between 2D and surgery was r = 0.50 (P <.05) and r = 0.26 (P = not significant).

CONCLUSIONS

ASD2 has a complex morphology. Three-dimensional echocardiography provides better qualitative and quantitative information on its dynamic geometry, location, and extension as compared with standard 2D echocardiography and might be useful for device selection during catheter-based closure of ASD2.

Low Incidence of Cerebrovascular Events in Patients with Incidental Atrial Septal Aneurysm

OBJECTIVES: The purpose of our investigation was to describe the echocardiographic characteristics of an atrial septal aneurysm (ASA) and associated cardiac abnormalities, to determine whether any echocardiographic characteristics are associated with cerebrovascular events, and to compare the cerebrovascular risk of ASA when it is an isolated and incidental finding with ASA associated with other cardiac abnormalities and diagnostic indications, including a cardiac source of embolus. METHODS: In 1605 consecutive patients referred for transesophageal echocardiography during open heart surgery, we identified 78 patients with ASA as an incidental finding (Group I). During the same period, this anomaly was found in 39 of 8014 consecutive patients referred to the echocardiographic laboratory for various diagnostic reasons (Group II). The frequency of cerebrovascular events and ASA characteristics was compared between these two groups. RESULTS: A total of 117 patients with ASA was included in the study: 60 males and 57 females with a mean age of 66.7 +/- 9.1 years. There were no significant differences in the echocardiographic characteristics of ASA or associated cardiac abnormalities between these two groups; no intracardiac or ASA associated thrombi were detected in either group. While only 6.4% of Group I had a clinical event, 23% of patients in Group II had a stroke or transient ischemic abnormality. CONCLUSIONS: The morphological characteristics of ASA and associated cardiac abnormalities do not distinguish patients at risk for cerebrovascular events. Although the presence of ASA may be a risk factor for embolic strokes, this risk is lower than previously thought.

Diagnosis of sinus venosus atrial septal defect with transesophageal echocardiography

BACKGROUND

Sinus venosus atrial septal defect (SVD) is underdiagnosed with transthoracic echocardiography because of its posterior (far field) location. Transesophageal echocardiography (TEE) should be ideally suited to diagnose SVD, given the proximity of the transducer to the defect.

METHODS AND RESULTS

A retrospective study was undertaken that used the medical history, echocardiographic findings, and surgical data of patients identified from computer records as having the diagnosis of SVD during the period in which TEE has been in use (1987 to 1995). Twenty-five patients (14 females and 11 males; median age, 45 years; range, 10 to 75 years) with SVD had TEE between 1987 and 1995. Prior transthoracic echocardiography clearly defined the SVD in 3 of these patients, and it was suspected in another 11 on the basis of color-flow imaging. Ten patients had unexplained dilatation of the right side of the heart, which prompted TEE examination. SVD was visualized with TEE in all 25 patients and ranged in size from 1 to 3 cm. Thirty-seven right-sided anomalous pulmonary venous connections were identified in 23 patients. No left-sided anomalous pulmonary venous connections were detected. Anatomic confirmation was obtained in all 23 surgical patients. No patient required preoperative cardiac catheterization for diagnosis.

CONCLUSIONS

TEE is accurate for the diagnosis of SVD and should be undertaken in any patient with unexplained dilatation of the right side of the heart. The associated pulmonary venous abnormalities can be identified with TEE. Cardiac catheterization for diagnostic purposes should not be required before surgical correction.

Intracardiac shunts

Unsuspected intracardiac shunts can be a cause of acute deterioration in critically ill patients. Shunts can be acquired or congenital conditions that become symptomatic only with changed physiologic conditions. Transesophageal echocardiography is an excellent tool for the diagnosis of intracardiac shunts.

Utility of transesophageal echocardiography in infective endocarditis. A review

Despite recent diagnostic and therapeutic advances, infective endocarditis continues to be a very serious illness, with high patient morbidity and mortality rates. The diagnosis of infective endocarditis has been based primarily on clinical signs and positive blood cultures. Echocardiography is currently recognized as the technique of choice for the detection of valvular vegetations, which are the hallmark of endocarditis. We briefly review the use of echocardiography in the diagnosis of suspected infective endocarditis, with emphasis on transesophageal echocardiography. High-resolution imaging of the cardiac valves with transesophageal echocardiography has proved to be invaluable in the management of infective endocarditis.

Imaging and sizing of atrial septal defects by magnetic resonance

BACKGROUND

Development of techniques for percutaneous closure of atrial septal defects (ASDs) makes accurate noninvasive sizing of ASDs important for appropriate patient selection.

METHODS AND RESULTS

Magnetic resonance (MR) images of ASDs were obtained in 30 patients (mean age, 41 +/- 16 years) by both spin-echo and phase-contrast cine MR imaging. Spin-echo images were obtained in two orthogonal views (short-axis and four-chamber) perpendicular to the plane of the ASD. Spin-echo major and minor diameters were measured, and spin-echo defect area was calculated. Phase-contrast cine MR images were obtained in the plane of the ASD, and cine major diameter and defect area were measured from the region of signal enhancement or phase change due to shunt flow across the defect. MR measurements were compared with templates cut during surgery to match the defect or with ASD diameter determined by balloon sizing at catheterization. ASD size measured from cine MR images (y) agreed closely with catheterization and template standards (x). For major diameter, y = 0.78x + 5.7, r = .93, and SEE = 3.4 mm. On average, spin-echo measurements overestimated major diameter and area of secundum ASDs by 48% and 125%, respectively.

CONCLUSIONS

Phase-contrast cine MR images acquired in the plane of an ASD define the defect shape by the cross section of the shunt flow stream and allow noninvasive determination of defect size with sufficient accuracy to permit stratification of patients to closure of the defect by catheter-based techniques versus surgery. Spin-echo images, on the other hand, are not adequate for defining ASD size, because septal thinning adjacent to a secundum ASD may appear to be part of the defect.

Detection of partial anomalous right pulmonary venous return with an intact atrial septum by transesophageal echocardiography

Partial anomalous pulmonary venous drainage with intact atrial septum is a rare congenital anomaly. We report a case of a 63-year-old woman who recently had dyspnea on minimal exertion and was found to have pulmonary hypertension, right atrial enlargement, and right ventricular enlargement by two-dimensional transthoracic echocardiography. Transesophageal echocardiography demonstrated anomalous venous drainage of the right lung into the superior vena cava with an intact interatrial septum. This diagnosis was confirmed by angiography and the patient underwent successful repair. This case illustrates the importance of locating all four pulmonary veins in patients with pulmonary hypertension or suspected intracardiac shunt in addition to scanning the atrial septum.

Paradoxical embolism. An underrecognized problem

Despite reports of the clinical presentations and devastating consequences of paradoxical embolus (PDE) for more than a century, this diagnosis continues to be frequently missed. Because the prevalence of patent foramen ovale (PFO) is 27 to 35% in the normal population and the presence of deep vein thrombosis or pulmonary embolus may not be clinically obvious, a high suspicion for PDE is needed in the event of unexplained arterial occlusion. While contrast echocardiography and transcranial Doppler ultrasound have facilitated clinical recognition of PDE, the optimum approach to diagnosis requires clarification. Primary therapy for patients with PDE is anticoagulation, with thrombolytics considered in carefully selected individuals, but there is little published information regarding long-term treatment and outcomes. Prevention remains essential whenever possible. It is not yet defined whether prophylactic treatment of persons with recognized predispositions to PDE (eg, PFO and pulmonary hypertension) is beneficial.

Atrial septal aneurysm in adult patients. A multicenter study using transthoracic and transesophageal echocardiography

BACKGROUND

An atrial septal aneurysm (ASA) is a well-recognized abnormality of uncertain clinical relevance. We reevaluated the clinical significance of ASA in a large series of patients. The aims of the study were to define morphological characteristics of ASA by transesophageal echocardiography (TEE), to define the incidence of ASA-associated abnormalities, and to investigate whether certain morphological characteristics of ASA are different in patients with and without previous events compatible with cardiogenic embolism.

METHODS AND RESULTS

Patients with ASA were enrolled from 11 centers between May 1989 and October 1993. All patients had to undergo transthoracic and transesophageal echocardiography within 24 hours of each other; ASA was defined as a protrusion of the aneurysm > 10 mm beyond the plane of the atrial septum as measured by TEE. Patients with mitral stenosis or prosthesis or after cardiothoracic surgery involving the atrial septum were excluded. Based on these criteria, 195 patients 54.6 +/- 16.0 years old (mean +/- SD) were included in this study. Whereas TEE could visualize the region of the atrial septum and therefore diagnose ASA in all patients, ASA defined by TEE was missed by transthoracic echocardiography in 92 patients (47%). As judged from TEE, ASA involved the entire septum in 100 patients (51%) and was limited to the fossa ovalis in 95 (49%). ASA was an isolated structural defect in 62 patients (32%). In 106 patients (54%), ASA was associated with interatrial shunting (atrial septal defect, n = 38; patent foramen ovale, n = 65; sinus venosus defect, n = 3). In only 2 patients (1%), thrombi attached to the region of the ASA were noted. Prior clinical events compatible with cardiogenic embolism were associated with 87 patients (44%) with ASA; in 21 patients (24%) with prior presumed cardiogenic embolism, no other potential cardiac sources of embolism were present. Length of ASA, extent of bulging, and incidence of spontaneous oscillations were similar in patients with and without previous cardiogenic embolism; however, associated abnormalities such as atrial shunts were significantly more frequent in patients with possible embolism.

CONCLUSIONS

As shown previously, TEE is superior to the transthoracic approach in the diagnosis of ASA. The most common abnormalities associated with ASA are interatrial shunts, in particular patent foramen ovale. In this retrospective study, patients with ASA (especially with shunts) showed a high frequency of previous clinical events compatible with cardiogenic embolism; in a significant subgroup of patients, ASA appears to be the only source of embolism, as judged by TEE. Our data are consistent with the view that ASA is a risk factor for cardiogenic embolism, but thrombi attached to ASA as detected by TEE are apparently rare.

Saline contrast and colour Doppler transoesophageal echocardiography in detecting a patent foramen ovale and right-to-left shunts in stroke patients

A paradoxical embolism due to right-to-left shunt through a patent foramen ovale (PFO) can be responsible for stroke and other ischaemic cerebral events. We studied the usefulness of saline contrast transoesophageal echocardiography after the Valsalva manoeuvre in detecting PFO and right-to-left shunts in 28 adult patients without known reason for a recent stroke. The results were compared with conventional transthoracic colour Doppler and with transoesophageal colour Doppler techniques. A PFO was found in 24 patients (86%) of our selected study population, whereas in four patients no PFO was found. A PFO with left-to-right shunt could be diagnosed by transthoracic colour Doppler echocardiography in only one case. A PFO with left-to-right shunt was found by transoesophageal colour Doppler echocardiography in 17 patients (61%), but in only three of them was a right-to-left shunt detected, even after the Valsalva manoeuvre. In contrast, a PFO with right-to-left shunt could be detected in 21 patients (75%) by using saline contrast transoesophageal echocardiography with the Valsalva manoeuvre. However, the method was unable to detect three cases of PFO with only left-to-right shunt, which were detected by colour Doppler transoesophageal echocardiography. In conclusion, our results show that saline contrast transoesophageal echocardiography with the Valsalva manoeuvre greatly improves the echocardiographic detection of PFO with right-to-left shunts in stroke patients.

Detection of cardiovascular shunts by transesophageal echocardiography in patients with pulmonary hypertension of unexplained cause

The purpose of this study was to validate the usefulness of transesophageal echocardiography (TEE) in the assessment of cardiovascular shunts in patients with pulmonary hypertension (PH) of unexplained cause. Twenty-four adult patients, 16 women, 8 men; 15 to 70 years of age, with PH of unexplained cause were studied. All were examined by transthoracic echocardiography (TTE) and TEE. TTE showed the ventricular septal defect in two patients, muscular type in one and perimembranous type in the other. TEE showed the atrial septal defect in eight patients (secundum type in six and primum type in the remaining) and the patient ductus arteriosus in six patients, which were not seen by TTE. The ventricular septal defect shown by TTE was also found by TEE. Patients with a ventricular septal defect were also associated with a patient ductus arteriosus. Among 14 patients with cardiovascular lesions, nine patients displayed a pattern of bidirectional shunt, four a pure left-to-right shunt, and the remaining one a pure right-to-left shunt. All of the cardiovascular defects could be confirmed by passage of the catheter across the defect at cardiac catheterization. In light of PH, transthoracic identification of cardiovascular shunts is difficult because of the low velocity across the defect. In this study, we found that TEE was superior to TTE in detecting and localizing cardiovascular malformations in patient with PH.

Higher prevalence of atrial septal aneurysms in patients with ischemic stroke of unknown cause

Atrial septal aneurysms (ASA) are frequent findings on transesophageal echocardiographies. Whether they are more frequent in patients with cerebral ischemia of unknown cause remains unclear. We investigated this question in 154 consecutive patients with an ischemic stroke or transient ischemic attack. The 16 patients with ASA were younger, less likely to have arterial hypertension and more likely to have a patent foramen ovale (PFO) or an unknown cause of stroke, but they did not differ for number and side of infarcts, other demographic data and vascular risk factors. Patients with ASA unassociated to PFO were also more likely to have an unknown cause of stroke. These findings lead to the hypothesis that ASA might be sources of cerebral emboli.

Three-dimensional ultrasound imaging of the atrial septum: normal and pathologic anatomy

OBJECTIVES

This study investigated the feasibility of producing three-dimensional gray scale ultrasound images of the atrial septum to demonstrate normal and pathologic anatomy.

BACKGROUND

Two-dimensional echocardiography is the principal technique used for imaging the atrial septum. Although the diagnostic accuracy of two-dimensional echocardiography is high, its capability for displaying complex three-dimensional relations is limited.

METHODS

Three-dimensional ultrasound images were reconstructed from tomographic images obtained during routine transesophageal echocardiographic examinations. Custom-made semi-automatic algorithms for image enhancement, interpolation and segmentation were used to produce volumetric gray scale images. Volume-rendered displays of the atrial septum were generated for analysis. Sequential three-dimensional images were generated through the cardiac cycle and displayed cinematographically to permit assessment of motion.

RESULTS

The three-dimensional images obtained from six patients clearly demonstrated normal and pathologic anatomy of the atrial septum, including atrial septal defects, atrial septal aneurysm and aortic valve ring abscess. The images could be manipulated electronically to demonstrate spatial relations and internal structural details.

CONCLUSIONS

Three-dimensional gray scale reconstruction of ultrasound images obtained by transesophageal echocardiography is feasible. These images clearly demonstrate anatomic details and spatial relations. The gray scale images may be interactively manipulated to optimize the clinician's visualization of the atrial septum and its associated pathologic conditions.

Detection of left-to-right shunt in atrial septal defect by negative contrast echocardiography: a comparison of transthoracic and transesophageal approach

The occurrence of a right atrial negative contrast effect as an indicator of left-to-right shunt was studied in 101 patients with atrial septal defect by peripheral venous contrast injection during transthoracic and transesophageal echocardiography. Confirmation of the diagnosis was provided by cardiac catheterization or by autopsy in 72 (72%) patients. The defect could be visualized directly in 57 (57%) patients during the transthoracic and in 93 (93%) during the transesophageal examination (p < 0.001). A negative right atrial echo contrast effect was observed in 53 of 92 (58%) patients from the transthoracic and in 86 of 92 (93%) patients from the transesophageal approach (p < 0.001). Among these were seven (7%) patients with an aneurysmal interatrial septum but no directly visible defect during conventional transesophageal imaging. Appearance of contrast in the left atrium indicating right-to-left shunting was seen in 70 of 92 (76%) patients from the transthoracic and in 91 of 92 (99%) patients from the transesophageal approach (p < 0.001). Contrast injection during transesophageal imaging also helped identify additional malformations in 12 (12%) patients. Thus transesophageal echocardiography with echo contrast injection is a very reliable diagnostic method in patients with suspected atrial septal defect.

Transthoracic echocardiography versus transesophageal echocardiography in detecting cardiac sources of embolism

Although the yield of potential cardiac sources of embolism by echocardiography in patients with stroke and arterial embolism has been low, with the advent of transesophageal echocardiography, a renewed enthusiasm for echocardiography in these patients has developed. This article reviews the six major studies comparing transthoracic to transesophageal echocardiography in the search for potential cardiac sources of embolism. The overall yield of transesophageal echocardiography in these studies for potential cardiac sources of embolism is 43% compared to 14% by transthoracic echocardiography in a total of 367 patients. In patients without clinical cardiac disease, the yield is lower but still substantially higher by transesophageal echocardiography (24% compared to 7% by transthoracic echocardiography). For left atrial thrombus, left atrial spontaneous contrast, patent foreman ovale, and atrial septal aneurysm (ASA), transesophageal echocardiography is clearly superior than transthoracic echocardiography. Data on the detection of mitral valve prolapse and left ventricular thrombus are conflicting and neither method is clearly superior. In addition, transesophageal echocardiography identifies certain abnormalities including debris in the aorta and prosthetic strands that transthoracic echocardiography is incapable of identifying. Although transthoracic echocardiography should continue to be the initial screening modality for stroke patients, transesophageal echocardiography should be performed when surface findings are negative or equivocal in patients with likely cardioembolic stroke.

Transesophageal echocardiographic diagnosis of right to left shunting across the foramen ovale in adults without prior stroke

OBJECTIVES

The purpose of this study was to estimate the prevalence of potential right to left interatrial shunting and to quantify the morphologic characteristics of the fossa ovalis in adults without a prior history of stroke or systemic embolism.

BACKGROUND

Paradoxic embolization through a patent foramen ovale is an important cardiac mechanism for embolic stroke. Although anatomic and physiologic data obtained by transesophageal echocardiography increase the frequency of demonstration of potential cardiac sources of systemic embolism and occasionally can conclusively demonstrate the mechanism for embolic stroke, the prevalence and prognostic implications of these findings in neurologically healthy persons are still being actively investigated.

METHODS

Intraoperative transesophageal saline contrast echocardiography was performed on 50 adult patients without prior history of stroke or systemic embolism who were undergoing elective cardiovascular surgery.

RESULTS

No patient had a manifest atrial septal defect by right heart oximetric measurements or transesophageal Doppler echocardiographic examination. Eleven of the 50 patients demonstrated right to left atrial passage of saline contrast medium during apnea or after release of 20-cm H2O positive airway pressure, signifying patency of the foramen ovale. These 11 patients with a patent foramen ovale had increased total excursion of the flap valve (septum primum) of the fossa ovalis (1.3 +/- 0.7 cm) compared with findings in the 39 patients without a patent foramen ovale (0.3 +/- 0.5 cm, p < 0.001). All patients with a patent foramen ovale exhibited some mobility of the septum primum and 73% of these patients had > or = 1 cm total excursion of the septum primum. In contrast, 56% of patients without a patent foramen ovale exhibited no motion of the septum primum out of the plane of the atrial septum. The maximal diameter of the fossa ovalis was greater in patients with (1.4 +/- 0.4 cm) than in patients without (1.0 +/- 0.3 cm, p < 0.003) a patent foramen ovale.

CONCLUSIONS

Hypermobility of the septum primum and enlargement of the fossa ovalis are morphologic findings that occur in the presence of a patent foramen ovale.

Morphological variations of fossa ovalis atrial septal defects (secundum): feasibility for transcutaneous closure with the clam-shell device

OBJECTIVE--To assess the morphology of fossa ovalis atrial septal defects (FOASD; secundum atrial septal defect) to determine in what proportion percutaneous closure with the clam-shell device might be feasible. DESIGN--Review of the intraoperative description of the morphology and size of FOASD. PATIENTS--106 consecutive patients with FOASD. SETTING--A regional children's cardiac referral centre. MAIN OUTCOME MEASURES--Determination of morphology and size of FOASD. RESULTS--Morphological variations in the FOASD were found: (1) central FOASD, 70 (66%); (2) superior FOASD, 4 (3.7%); (3) inferior FOASD, 8 (7.6%); (4) posterior FOASD, 2 (1.9%); (5) subtotal absence of atrial septum, 3 (2.8%); (6) completely fenestrated FOASD, 10 (9.4%); (7) partially fenestrated FOASD, 9 (8.5%). Depending on its site, the edge of the FOASD may be close to important atrial structures such as the orifices of the superior and inferior caval veins, coronary sinus, and right pulmonary veins. The shape of the FOASD was usually oval with the major diameter ranging from 10 to 50 mm with a mean (SD) of 27.8 (0.93) mm. The minor diameter ranged from 4 to 30 mm with a mean (SD) of 15.3 (5.9) mm. The ratio of the major to minor diameter ranged from 1.0 to 5.0 with a mean of 2.01. Based on intraoperative measurement and description, it is postulated that it should be possible to close about 50% of these defects with the clam-shell device.

Comparison of color flow imaging and peripheral venous saline contrast during transesophageal echocardiography to evaluate right-to-left shunt at the atrial level

Intravenous injections of agitated saline (contrast) are used to identify right-to-left atrial shunt during transesophageal echocardiography (TEE). Color flow imaging (CFI) with TEE can be used to detect left-to-right atrial shunt but its application to detect right-to-left shunt is not known. We performed CFI and contrast during TEE in 72 patients for detection of right-to-left shunt. Frame-by-frame review of CFI demonstrated discrete laminar jets of the left side of the atrial septum at the lower or upper margin of the fossa ovalis (FO) in 41 (57%) of 72; only 22 had positive contrast. Timing of shunts was late diastolic or early systolic and not related to pulmonary venous inflow. The length of the FO at end-systole was greater in those with positive CFI compared to negative CFI (13.5 +/- 5 vs 11 +/- 4 mm, P = 0.02). CFI was positive for right-to-left shunt in ten of 14 with atrial septal aneurysms. Contrast was positive for right-to-left shunt in 29 (40%) of 72; all but six had positive CFI. The degree of left atrial opacification was minimal in 19 and moderate to severe in ten. FO size was greater in positive versus negative contrast (14 +/- 4 vs 11 +/- 5 mm, P = 0.02). Contrast was positive for shunt in ten of 14 with septal aneurysms. Thus, right-to-left atrial shunt more often occurs with increased FO size and septal aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Transesophageal contrast echocardiography and color flow mapping: methods of choice for the detection of shunts at the atrial level?

The detection of shunts at the atrial level is important, and a reliable means of diagnosis is required. Precordial contrast echocardiography is usually performed to detect such shunts. To investigate the advantages of transesophageal echocardiographic techniques, we studied 167 consecutive patients with both precordial and transesophageal echocardiography, using two-dimensional imaging with contrast techniques (with and without a Valsalva maneuver) and color flow mapping. A patent foramen ovale was diagnosed in 31 patients, an atrial septal defect in 11 (7 with bidirectional shunts), and a pulmonary arteriovenous fistula in 3 patients. All right-to-left shunts were detected with transesophageal contrast echocardiography. With these results used as the gold standard, the sensitivity of combined precordial techniques was 37% and that of transesophageal color flow mapping 46%. All left-to-right shunts were detected by transesophageal color flow mapping. With these results used as the gold standard, the sensitivities of both precordial color flow mapping and a transesophageal negative right atrial contrast study were 27%. We conclude that transesophageal contrast echocardiography is the echocardiographic method of choice for the detection of a right-to-left shunt at the atrial level, which cannot be excluded by negative results on precordial study or on transesophageal color flow map study. A left-to-right shunt at this level is best detected by transesophageal color flow mapping.

Diagnosis of patent foramen ovale by transesophageal echocardiography and association with cerebral and peripheral embolic events

This study compares the value of transthoracic (TTE) and transesophageal (TEE) color Doppler and contrast echocardiography for detecting a patent foramen ovale (PFO). A total of 238 patients were studied: 74 patients with a history of otherwise unexplained ischemic stroke, transient cerebral ischemic attacks or peripheral embolic events (group A), 48 with a history of similar episodes explained by other cardiac abnormalities (group B), and 116 with no embolic events (group C). A PFO was detected by contrast TEE in 50 of 238 patients (21%) compared with 45 patients (19%) by color Doppler TTE. In a subgroup of 198 patients, TEE results could be compared with TTE findings. No patient had a PFO identified by color Doppler TTE. Contrast TTE detected a PFO in 15 patients (8%) compared with contrast TEE which demonstrated a PFO in 44 of 198 patients (22%) (p less than 0.001). Prevalence of PFO by TEE was 22, 21 and 22% in groups A, B and C, respectively. A PFO was present in 50% of patients aged less than 40 years and otherwise unexplained ischemic stroke; this percentage was higher (p less than 0.05) than corresponding values found in all other groups. Thus, contrast and color Doppler TEE are significantly superior to TTE for detecting PFO. The prevalence of PFO is significantly increased in young adults with otherwise unexplained ischemic stroke.

Value of transesophageal color Doppler echocardiography for detection of different types of atrial septal defect in adults

In 121 adults, the value of transthoracic and transesophageal color Doppler echocardiography for detection of different types of atrial septal defect (ASD) or of partial anomalous pulmonary venous return was analyzed. The 121 patients had a total of 129 defects with left-to-right atrial shunting (including eight patients with two types of defects). All of six cases with primum-type ASD were diagnosed correctly by both echocardiographic methods. Ninety-seven patients showed a secundum-type ASD during transesophageal echocardiography: by transthoracic echocardiography, only eight (20%) of the 40 small defects (diameter < 5 mm) were detected as compared with 15 (83%) of the 18 defects with a diameter of 5 to 10 mm and all 39 defects with a diameter > 10 mm. A sinus venosus--type ASD was evident by transesophageal echocardiography in 11 patients, of which only one (9%) was demonstrated by the transthoracic approach. Partial anomalous pulmonary venous return was seen by transesophageal echocardiography in 13 patients but missed in two other patients in whom anomalous pulmonary venous return was subsequently identified by surgery (both with anomalous return of the upper right pulmonary vein into the superior vena cava). By use of the transthoracic technique, partial anomalous venous return was detected in only two cases, both of which had "scimitar syndrome." Compared with transthoracic echocardiography, the transesophageal approach is clearly superior in the detection of small secundum-type ASD, sinus venosus--type ASD, and partial anomalous pulmonary venous return.

Detection of patent foramen ovale by contrast transesophageal echocardiography

A series of 32 patients undergoing cardiac catheterization and/or operation to document the presence of patent foramen ovale (PFO) were studied. All were examined by contrast transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) during normal breathing and the Valsalva maneuver. A right-to-left shunt at the atrial level was visualized by contrast TEE in 14 patients during normal breathing and in 20 patients during the Valsalva maneuver. In comparison, contrast TTE revealed this shunt in only eight patients during normal breathing and in 12 patients during the Valsalva maneuver. All of the foramina proved to be patent by contrast TTE were also found by contrast TEE. All but one (19 of 20) patients, shown to have PFO by contrast TEE, could be confirmed at cardiac catheterization and/or operation. Using cardiac catheterization and/or operation as a gold standard, contrast TEE appears to be a more sensitive (100 percent vs 63 percent, p less than 0.005) and accurate (97 percent vs 78 percent, p less than 0.05) method than contrast TTE in the detection of PFO.

Transesophageal echocardiography

Transesophageal echocardiography has provided a new acoustic window to the heart, the great vessels, and the mediastinum. It provides anatomical, functional hemodynamic, and blood flow information. High-quality visualization of left atrial appendage, thoracic aorta, atrial septum, and mitral valvular apparatus can be obtained readily. We discuss historical and technical aspects of transesophageal echocardiography, anatomical views, and major clinical indications for this procedure. These indications include intracardiac masses, thoracic aortic dissection, endocarditis, prosthetic and native cardiac valve function assessment, as well as its value in the detection of intracardiac source of systemic emboli. Furthermore, the role of transesophageal echocardiography in the assessment of coronary artery and congenital heart disease and as an intraoperative diagnostic and monitoring technique is discussed.

Diagnostic value of transesophageal echocardiography in atrial septal aneurysm

Transthoracic and transesophageal echocardiography was performed in 40 consecutive adult patients with an atrial septal aneurysm. In 11 (27%) of 40 patients transthoracic echocardiography failed to demonstrate the lesion and the diagnosis was established by the transesophageal approach only. Interatrial shunting, assessed by echocardiographic contrast study and/or color flow mapping, was detected in 13 (54%) of 24 patients on transthoracic imaging and in 29 (76%) of 38 patients during transesophageal echocardiography. Identification of multiple fenestrations (n = 9) and thrombi within the aneurysm (n = 2) could be achieved only by transesophageal ultrasound. A cerebrovascular event of suspected embolic origin occurred in 20 (50%) of 40 patients; 11 (55%) of the 20 patients had repeated cerebral events. Except for mitral valve prolapse in 2 patients and spontaneous left atrial contrast phenomenon in 1 patient no other potential cardiac source of embolism could be identified by transesophageal echocardiography. A marked thickening of the aneurysm was present in 14 (70%) of 20 patients with a cerebrovascular event versus only 4 (20%) of 20 patients without a cerebrovascular event (p less than 0.01). The mechanism of embolization may be both primary thrombus formation within the aneurysm and paradoxical embolization through an interatrial communication as suggested by the findings on transesophageal ultrasound in 2 patients. Although the patients of this study represent a highly selected group it may be concluded that atrial septal aneurysm is a cardiac abnormality with embolic potential. Transesophageal echocardiography has to be regarded the imaging method of choice for evaluation of this lesion.

Complications of transesophageal echocardiography in ambulatory adult patients: analysis of 1500 consecutive examinations

Transesophageal echocardiography is a new approach that can be used to image cardiac structures. It combines two existing technologies: cardiac ultrasound and endoscopy. To obtain a cardiac image, the transesophageal probe has to be positioned properly within the esophagus. The first 1500 consecutive transesophageal echocardiographic examinations in ambulatory adult patients from one center were analyzed to identify conditions associated with failed esophageal intubation and procedural complications. Esophageal intubation was not achieved in 11 patients (0.73%). The reasons for the failure of intubation were operator inexperience, hypersensitive pharynx despite topical anesthesia, and cervical spondylosis. Six of those patients also had a history of dysphagia. Procedural complications were identified in seven patients (0.47%). Tracheal intubation was present in four patients, with immediate development of stridor and incessant cough in two patients. Atrial fibrillation developed in two patients--one had atrial myxoma and one had mitral stenosis. Bronchospasm developed during the transesophageal examination in one patient who was receiving long-term treatment for bronchial asthma. We conclude that transesophageal echocardiography is feasible in most adult patients in the ambulatory setting and that the complication rate is very low. Proper patient selection and preparation are crucial to the successful performance of this procedure.

Transesophageal echocardiography: procedures and clinical application

In existence for more than a decade, transesophageal echocardiography has gained renewed interest because of technologic advances including high resolution transducers, multiple imaging planes and Doppler color flow mapping. The heart is imaged from within the esophagus with a gastroscope-mounted transducer, obviating technical difficulties encountered in transthoracic echocardiography. Transesophageal echocardiography is utilized intraoperatively to monitor patients undergoing open heart surgery or high risk cardiac patients undergoing noncardiac surgery. In the ambulatory patient, the procedure facilitates imaging of many structures (including the left atrium and appendage, mitral and aortic native and prosthetic valves and thoracic aorta), with better resolution than that obtained by routine transthoracic echocardiography. Technical aspects of transesophageal echocardiography as well as its indications and limitations are reviewed.

Transesophageal color Doppler flow mapping of iatrogenic left-to-right interatrial shunting after percutaneous transluminal mitral valvotomy

Characteristics of transesophageal color Doppler flow mapping of iatrogenic left-to-right interatrial shunts were assessed in 58 patients, 1 to 994 days after percutaneous transluminal mitral valvotomy. Transesophageal color Doppler flow mapping detected 22 cases of interatrial shunt whereas transthoracic two-dimensional echocardiography visualized only five interatrial septal defects. Five types of color Doppler flow patterns of interatrial shunts were found: type 1, a bluish jet passing through the interatrial septum into the right atrium with a small bluish proximal flow in the left atrium (50%); type 2, a bluish jet passing through the interatrial septum into the right atrium without a proximal flow (13.6%); type 3, a predominant bluish proximal flow in the left atrium passing through the interatrial septum with minimal flow entering into the right atrium (18.2%); type 4, an "en face" bluish jet in the right atrium (4.5%); and type 5, a "wall jet" with proximal flow adhering to and entering into the interatrial septum (13.6%). Oximetry demonstrated increased pulmonary-to-systemic flow ratio (range 1.07 to 3.32) in 11 patients (50%), which was significantly correlated with the maximal jet area derived from color Doppler flow mapping (r = 0.80, P = 0.001). Thus, transesophageal color Doppler flow mapping is useful in detection of left-to-right interatrial shunts after percutaneous transluminal mitral valvotomy, and recognition of the variable types of color flow mapping may further help identify these atypical interatrial shunts.

Atrial septal aneurysm and stroke: a transesophageal echocardiographic study

The prevalence and morphologic characteristics of atrial septal aneurysms identified by transesophageal echocardiography in 410 consecutive patients are described. Two groups of patients were compared: Group I consisted of 133 patients referred for evaluation of the potential source of an embolus and Group II consisted of 277 patients referred for other reasons. An atrial septal aneurysm was diagnosed by transesophageal echocardiography in 32 (8%) of the 410 patients. Surface echocardiography identified only 12 of these aneurysms. Atrial septal aneurysm was significantly more common in patients with stroke (20 [15%] of 133 vs. 12 [4%] of 277) (p less than 0.05); right to left shunting at the atrial level was demonstrated in 70% of patients in Group I and 75% of patients in Group II by saline contrast echocardiography. Four patients in Group I had an atrial septal defect with additional left to right flow. There was no difference between the two groups in aneurysm base width, total excursion or left atrial or right atrial excursion. However, Group I patients had a thinner atrial septal aneurysm than did Group II patients. It is concluded that an atrial septal aneurysm occurs commonly in patients with unexplained stroke, is more frequently detected by transesophageal echocardiography than by surface echocardiography and is usually associated with right to left atrial shunting. Treatment (anticoagulant therapy vs. surgery) of atrial septal aneurysm identified in stroke patients can be determined only by long-term follow-up studies.

Transesophageal echocardiographic demonstration of distinct mechanisms for right to left shunting across a patent foramen ovale in the absence of pulmonary hypertension

The optimal visualization of the atrial septum and fossa ovalis by transesophageal echocardiography was utilized to demonstrate saline contrast transit across the atrial septum and to relate it to the motion of the flap valve (septum primum) of the fossa ovalis. In three cases, three distinct mechanisms of right to left interatrial shunting in the absence of right ventricular systolic hypertension were identified: 1) transient spontaneous reversal of the left to right atrial pressure differential with each cardiac cycle; 2) sustained elevation of right atrial pressure above left atrial pressure induced by respiratory maneuvers; and 3) aberrant flow redirection across the foramen ovale due to a large right atrial mass. Any of these three mechanisms may be operative during paradoxic embolism in the absence of elevation of right ventricular pressures.

Transesophageal echocardiography for congenital heart disease

Surface echocardiographic imaging of small children is routinely successful in defining anatomical details and Doppler flow patterns with even the most complex congenital cardiac malformations. However, in larger children or adults, imaging is frequently limited. A recent expansion of the role of echocardiography is intraoperative epicardial imaging. Epicardial and postoperative imaging, however, have significant limitations. To avoid some of these limitations, transesophageal echocardiography has increasingly been used in the arena of congenital heart disease. The more recent development of small sized gastroscopic probes has allowed transesophageal echocardiographic assessment of congenital heart disease in children down to newborn size. As detailed studies of individual lesions are reported, it has become clear that the mere presence of a congenital heart defect is not an indication for transesophageal echocardiography in most children if imaging can be accomplished by surface examination. However, transesophageal echocardiography may be indicated for the intraoperative or postoperative assessment of that defect, particularly when repair has been difficult or is known to be associated with significant residual abnormalities. Cardiac structures encountered with horizontal and vertical imaging plane transducers have been described and should be completely familiar to the examining echocardiographer.

Color Doppler echocardiographic assessment of atrial septal defect size: correlation with surgical measurements

In patients with atrial septal defect (ASD), color flow Doppler echocardiography provides visualization of the transseptal jet, the maximal dimension of which can be assumed to correspond to the maximal dimension of the true orifice. To test whether color flow Doppler echocardiography can provide an alternative method for measurement of ASD size, we studied 63 consecutive patients with echocardiographic evidence of ASD. In 48 patients the maximal dimension of the jet was measured in the parasternal, apical, or subcostal four-chamber view or in the parasternal short-axis view. In the remaining 15 patients transesophageal echocardiography was performed because of transthoracic views were inadequate. The transesophageal studies also measured, from two-dimensional images, the maximal transverse discontinuity in the atrial septum. All patients underwent surgical repair, during which the surgeon directly measured the maximal dimension of ASD. Linear regression equations were performed to compare transthoracic and transesophageal dimensions to those measured at operation. Correlation coefficients were as follows for transthoracic versus surgical measurements: r = 0.745, standard error = 4.35, p less than 0.001. Transesophageal measurements derived from both two-dimensional images and echocardiographic jet width showed similar excellent correlation with surgical measurements (n = 0.91, standard error = 4.33, p less than 0.001; and r = 0.919, standard error = 4.42, p less than 0.001, respectively). We conclude that ASD size derived from color flow Doppler echocardiography shows a good correlation with the anatomic maximal dimension observed at operation. Both transesophageal color flow Doppler echocardiography of jet width and direct surgical measurement of the defect provide an accurate estimation of ASD size.

Asymptomatic left ventricular malposition of a transvenous pacemaker lead through a sinus venosus defect: follow-up over 17 years

The case of a woman with an asymptomatic transvenous left ventricular endocardial pacemaker lead is presented. The chest X ray and the electrocardiogram suggested pacemaker catheter malposition. By two-dimensional echocardiography, the pacemaker lead was shown to cross from the left atrium through the mitral valve and implant in the left ventricular endocardium. The underlying sinus venosus defect and the passage of the electrode through this interatrial communication were directly visualized by transesophageal echocardiography. No thrombotic material attached to the lead was detected corresponding to the patient's uneventful course for surprisingly more than 17 years without evidence of past or present neurological deficiencies or of peripheral embolic phenomena. Thus, no operative correction was performed. Warfarin sodium therapy, however, was initiated.

Transoesophageal echocardiographic assessment of primum, secundum and sinus venosus atrial septal defects

We compared the ability of transthoracic and transoesophageal echocardiography to determine the presence and site of an atrial septal defect and associated anomalous pulmonary venous connexions in 13 school age children (aged 5 to 15 years) and 12 adults (aged 25 to 68 years). Transthoracic echocardiography detected atrial septal defects in 12 children and 6 adults. Transoesophageal echocardiography confirmed the position of 16 (13 secundum, 3 primum) of these 18 defects but altered the diagnosis from a secundum defect to a sinus venosus defect in one and from a sinus venosus defect to a high secundum defect in another. In addition to these 18, transoesophageal echocardiography diagnosed a defect in 5 adults (3 secundum and 2 sinus venosus defects) and 1 child (secundum defect). In an adult with inconclusive transthoracic findings, transoesophageal echocardiography enabled clear visualisation of the atrial septum and excluded an atrial septal defect. Transoesophageal echocardiography showed anomalous attachment of a pulmonary vein into the region of a sinus venosus defect (n = 3) but did not show anomalous connexions to the superior caval vein (n = 3) or the inferior caval vein (n = 1). Transoesophageal echocardiography provides a reliable method of diagnosing or excluding an atrial septal defect in patients with inconclusive transthoracic findings and is of particular diagnostic value in sinus venosus defects.