Transesophageal Doppler color flow mapping assessment of atrial septal defect

ACR Appropriateness Criteria® Pulmonary Arteriovenous Malformation (PAVM): 2023 Update

Pulmonary arteriovenous malformations (PAVMs) occur in 30% to 50% of patients with hereditary hemorrhagic telangiectasia. Clinical presentations vary from asymptomatic disease to complications resulting from the right to left shunting of blood through the PAVM such as paradoxical stroke, brain abscesses, hypoxemia, and cardiac failure. Radiology plays an important role both in the diagnosis and treatment of PAVM. Based on different clinical scenarios, the appropriate imaging study has been reviewed and is presented in this document. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Patent foramen ovale and atrial septal defect

Atrial septal defects (ASD) are among the most common congenital heart diseases encountered in adulthood. Patent foramen ovale (PFO) is present in up to 25% of the population. ASD could present as isolated lesion or in association with more complex congenital heart disease form as tetralogy of Fallot, or Ebstein's anomaly of tricuspid valve. There is a wide range of clinical presentation ranging from asymptomatic subjects surviving to adulthood undiagnosed to subjects presenting with right heart failure and severe pulmonary vascular disease (Eisenmenger syndrome). This manuscript is an in depth review of the complex atrial septation, the variable clinical presentation of ASD and PFO, and its clinical and therapeutic implications.

Transthoracic contrast echocardiography using vitamin B6 and sodium bicarbonate as contrast agents for the diagnosis of patent foramen ovale

To evaluate the utility of transthoracic contrast echocardiography (cTTE) using vitamin B6 and sodium bicarbonate as contrast agents for diagnosing right-to-left shunt (RLS) caused by patent foramen ovale (PFO) compared to that of transesophageal echocardiography (TEE). We investigated 125 patients admitted to our neurology department with unexplained cerebral infarction and migraine. All patients underwent cTTE using vitamin B6 and sodium bicarbonate as contrast agents, after which they underwent transthoracic echocardiography. The Doppler signal was recorded during the Valsalva maneuver, and TEE examinations were performed. The feasibility, diagnostic sensitivity, and safety of cTTE and TEE for PFO recognition were compared. Evidence of PFO was found in 49 (39.20%) patients with cTTE, more than were detected with TEE (39, 31.20%) (χ²=5.0625, P=0.0244). cTTE had a sensitivity of 92.31% and a specificity of 84.88% for diagnosing PFO, showing high concordance with TEE for PFO recognition (κ=0.72). Further, results of a semi-quantitative evaluation of PFO-RLS by cTTE were better than those with TEE (Z=-2.011, P=0.044). No significant adverse reaction was discovered during cTTE examination. cTTE using vitamin B6 and sodium bicarbonate as contrast agents has relatively good sensitivity and specificity for diagnosing RLS caused by PFO when compared with those for TEE. Using vitamin B6 and sodium bicarbonate as contrast agents to perform cTTE is recommended for detecting and diagnosing the PFO due to its simplicity, non-invasive character, low cost, and high feasibility.

Evolution of surgical techniques for atrial septal defect repair in adults: A 10-year single-institution experience

OBJECTIVE

We retrospectively analyzed our experience in atrial septal defect repair with varied minimally invasive surgical approaches.

METHODS

From 1997 to 2006, 64 patients underwent surgical repair of atrial septal defects in our center. Patients were grouped into four groups according to the approach used; group 1 (n = 16), partial lower sternotomy; group 2 (n = 20), right anterior small thoracotomy with transthoracic clamping; group 3 (n = 4), right anterior small thoracotomy with endoaortic balloon clamping; and group 4 (n = 24), totally endoscopic approach with the use of the da Vinci surgical system (Intuitive Surgical, Mountain View, Calif). Preoperative diagnosis was a large secundum type atrial septal defect in 60 patients, primum type in 3 patients, and sinus venosus type in 1 patient.

RESULTS

Complete atrial septal defect closure was verified by intraoperative transesophageal echocardiography in all patients. There was neither perioperative mortality nor major complication. Groups 3 and 4 had significantly longer aortic crossclamp, cardiopulmonary bypass, and skin-to-skin operative times than had groups 1 and 2 (P = .000). All groups had similar ventilation time, postoperative drainage, and intensive care unit and hospital stays. Only 2 patients in group 4 were converted to the minithoracotomy owing to endoaortic balloon failure. During the follow-up of 30 +/- 24.3 months, 1 patient in group 3 was reoperated on owing to significant residual shunting.

CONCLUSIONS

All types of atrial septal defects can be repaired via those four different approaches as safely as can be done by the conventional technique. General complications during surgical procedures are negligible. These approaches may be considered a standard treatment and an adjunct to transcatheter treatment options in atrial septal defect repair.

Balloon sizing and transcatheter closure of acute atrial septal defects guided by magnetic resonance fluoroscopy: Assessment and validation in a large animal model

PURPOSE

To quantitatively assess atrial septal defects (ASDs) with small shunts using MRI followed by transcatheter closure monitored by MR fluoroscopy.

MATERIALS AND METHODS

Acute ASDs were created in 14 pigs under x-ray fluoroscopy. Six animals were studied in order to select MR-compatible delivery systems and imaging strategies. ASDs in eight animals were examined with balloon sizing under MR fluoroscopy, flow measurements, and contrast media injections, after which transcatheter closure was performed under MR fluoroscopy. The delivery system was assembled from commercially available materials.

RESULTS

The ratio of pulmonary to systemic flow (Qp/Qs) was reduced from 1.23 +/- 0.15 before ASD closure to 1.07 +/- 0.11 after ASD closure (P < 0.001). In two out of eight animals Qp/Qs was close to 1.0 before closure despite the presence of defects >15 mm. The ASDs were measurable with MR balloon sizing in all of the animals. Balloon sizing was identical with MR (16.9 +/- 2.3 mm) and x-ray fluoroscopy (17.1 +/- 1.3 mm). The in-house-assembled delivery system allowed successful placement of closure devices under MR guidance.

CONCLUSION

Assessment and closure of small shunts with MR fluoroscopy is feasible. A barrier to the rapid implementation of transcatheter closure in patients is uncertainty about the MR safety of guidewires and device delivery systems.

Validation of the accuracy of both right and left ventricular outflow volume determinations and semiautomated calculation of shunt volumes through atrial septal defects by digital color Doppler flow mapping in a chronic animal model

OBJECTIVES

The aim of the present study was to quantitate shunt flow volumes through atrial septal defects (ASDs) in a chronic animal model with surgically created ASDs using a new semiautomated color Doppler flow calculation method (ACM).

BACKGROUND

Because pulsed Doppler is cumbersome and often inappropriate for color flow computation, new methods such as ACM are of interest.

METHODS

In this study, 13 to 25 weeks after ASDs were surgically created in eight sheep, a total of 24 hemodynamic states were studied at a separate open chest experimental session. Electromagnetic (EM) flow probes and meters were used to provide reference flow volumes as the pulmonary and aortic flow volumes (Qp and Qs) and shunt flow volumes (Qp minus Qs). Epicardial echocardiographic studies were performed to image the left and right ventricular outflow tract (LVOT and RVOT) forward flow signals. The ACM method digitally integrated spatial and temporal color flow velocity data to provide stroke volumes. RESULTS Left ventricular outflow tract and RVOT flow volumes obtained by the ACM method agreed well with those obtained by the EM method (r = 0.96, mean difference = 0.78 +/- 1.7 ml for LVOT and r = 0.97, mean difference = -0.35 +/- 3.6 ml for RVOT). As a result, shunt flow volumes and Qp/Qs by the ACM method agreed well with those obtained by the EM method (r = 0.96, mean difference = -1.1 +/- 3.6 ml/beat for shunt volumes and r = 0.95, mean difference = -0.11 +/- 0.22 for Qp/Qs).

CONCLUSIONS

This animal study, using strictly quantified shunt flow volumes, demonstrated that the ACM method can provide Qp/Qs and shunt measurements semiautomatically and noninvasively.

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.

A rare case of inferior venacaval type of atrial septal defect in an adult: echocardiographic features

We report a rare type of atrial septal defect with communication between the left atrium and the inferior vena cava. This type of defect has been referred to as a low sinus venous type of atrial septal defect because of its developmental origin, and possibly is caused by defective absorption of the left venous valve of the sinus venosus into the septum secundum. Detailed echocardiographic features are discussed.

Transesophageal echocardiography

This article presents an overview of the benefits and efficacy of transesophageal echocardiography (TEE) in the critically ill patient. The echocardiographic evaluation of ventricular function both regional and global, is discussed with special emphasis on ischemic heart disease; assessment of preload, interrogation of valvular heart disease (prosthetic and native) and its complications; endocarditis and its complications; intracardiac and extracardiac masses, including pulmonary embolism; aortic diseases (e.g., aneurysan, dissection, and traumatic tears); evaluation of patent foramen ovale and its association with central and peripheral embolic events; advancements in computer technology; and finally, the effect of TEE on critical care.

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.

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.

Assessment of right-to-left shunt flow in atrial septal defect by transesophageal color and pulsed Doppler echocardiography

To investigate the clinical significance and problems of right-to-left (R-L) shunt flow dynamics in atrial septal defects, we performed transesophageal color and pulsed Doppler echocardiography in 30 patients with atrial septal defects of the ostium secundum type. The 30 patients consisted of 20 with a pulmonary artery systolic pressure of less than 40 mm Hg, four with a pressure of 40 to 60 mm Hg, three with a pressure of 90 mm Hg or more, two patients with pulmonic stenosis, and one patient with Ebstein's anomaly. R-L shunting was determined by the presence of a shunt flow signal across the defect during each cardiac cycle. The time of R-L shunt flow was compared with the various parameters obtained by echocardiography and cardiac catheterization. R-L shunt flow signals were detected at the following times: (1) at the onset of ventricular contraction or the closing phase of the tricuspid valve in five patients with isolated atrial septal defect. These patients showed an increase of mean right atrial pressure but had no severe pulmonary hypertension; (2) during ventricular systole in five of 26 patients with tricuspid regurgitation and one patient with Ebstein's anomaly. The tricuspid regurgitant signal was directed toward the ostium of the defect in three patients and was massive in the other patients; (3) during middiastole in three patients without pulmonary hypertension. These patients showed massive left-to-right shunt flow from end systole to early diastole; and (4) during atrial systole in three patients with severe pulmonary hypertension and two patients with pulmonic stenosis. The former, in particular, showed the aliasing signal as a high-speed shunt flow. In two of the three patients with severe pulmonary hypertension, R-L shunting continued from atrial systole to early ventricular systole and was also observed in early diastole. R-L shunt flow was detected in patients with atrial septal defects not only with pulmonary hypertension but also without pulmonary hypertension and was influenced by the right atrial pressure in the phase of tricuspid valve closing, the volume or direction of tricuspid regurgitation, rebound flow caused by massive left-to-right shunt flow, the grade of right ventricular distensibility or the complication of pulmonary hypertension, and complications with other cardiac anomalies. Thus R-L shunt flow in patients with atrial septal defects was detected easily by transesophageal color and pulsed Doppler echocardiography because of the high efficiency of this method for its detection.

Transesophageal echocardiographic diagnosis of pulmonary arteriovenous malformation. Role of contrast and pulsed Doppler echocardiography

Contrast echocardiography produced by peripheral injection of agitated saline solution is widely used for detecting intracardiac and intrathoracic extracardiac shunts, like pulmonary arteriovenous malformation (PAVM). Currently, localization of PAVM requires pulmonary angiography even after detection by computed tomography of the chest. Pulsed Doppler along with contrast echocardiography of the pulmonary veins performed during transesophageal echocardiography may aid in the localization of PAVM and in its diagnosis.

Visualization of sinus venosus-type atrial septal defect by biplane transesophageal echocardiography

In this article we describe three patients in whom biplane transesophageal echocardiography was useful in diagnosing sinus venosus type atrial septal defects. In two patients, diagnosis of anomalous pulmonary venous drainage was made correctly by biplane transesophageal echocardiography.

Right-to-left shunt across atrial septal defect related to tricuspid regurgitation: assessment by transesophageal Doppler echocardiography

The purpose of this study was to assess the factors involved in the development of the right-to-left (R-L) shunt in patients with atrial septal defect (ASD), especially the role of tricuspid regurgitation (TR). Thirty-one consecutive patients with ASD underwent transesophageal Doppler echocardiography to determine the size of ASD, the shunt flow, and the TR flow, and they were compared with hemodynamics examined by cardiac catheterization. Sixteen patients with the R-L shunt were older (53 +/- 11 vs 34 +/- 9 years; p < 0.001) and had higher pulmonary arterial pressure (36 +/- 17 vs 25 +/- 5 mmHg; p < 0.05) and a greater Qp/Qs (3.6 +/- 1.2 vs 2.4 +/- 0.9 L/min; p < 0.01) as compared with 15 patients with the pure left-to-right shunt. In six of 21 patients with TR, the regurgitant flow oriented toward ASD and blew into the left atrium through the defect. Besides the deviation of TR flow, the prevalences of the maximum diameter of ASD > 2.5 cm and the maximal TR flow area > 4 cm2 were significantly higher in the six patients as compared with patients with TR not related to the R-L shunt (p < 0.05 and p < 0.05), despite the pulmonary arterial pressure being similar in the two groups. Reversal of pressure gradient between the left and right atrium was not observed during the cardiac cycle in all patients. In conclusion, TR is a determinant of the R-L shunt in patients with ASD even in the absence of the reversal of pressure gradient between the left and right atrium.

Routine use of transesophageal echocardiography and color flow imaging in the evaluation and treatment of children with congenital heart disease

We reviewed our experience with transesophageal echocardiography (TEE) and color flow imaging in 157 consecutive patients with known or suspected heart disease to ascertain the impact of this technology on patient care. TEE was performed for diagnostic purposes (22/157), during interventional cardiac catheterizations (13/157), and during operative procedures (122/157). Diagnostic studies were performed after transthoracic echocardiography (TTE) in 21 of 22 patients. TEE was performed because TTE was inconclusive (15/21) or failed to provide sufficient detail of an abnormality (6/21). TEE detected an abnormality in 6 of 15 inconclusive TTEs. TEE was helpful during interventional cardiac catheterizations, particularly during umbrella closure of septal defects and in patients with complex venous and atrial anatomy undergoing transseptal puncture. TEE studies performed before cardiac operations significantly changed the diagnosis in only 5 of 122 (4%) patients, but the information changed the surgical approach in 4 of 5 of these patients. Postoperative TEE assessment more frequently changed care and resulted in further surgical management in 9 of 122 (7%) or a change in medical management in 6 of 122 (5%) patients. TEE was discontinued because of complications before studies were completed in only 4 of 157 (3%) patients. TEE and color flow imaging is a useful adjunct to care of children with known or suspected congenital heart disease.

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

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

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.

Transesophageal echocardiography in adults with congenital cardiopathies

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

Atrial septal defect after balloon mitral valvuloplasty: a transesophageal echocardiographic study

Fifty patients with rheumatic mitral stenosis aged twelve to thirty-six (twenty +/- six) years were studied by two-dimensional, pulsed and color Doppler echocardiography during, seventy-two hours after, and biweekly for three months after balloon mitral valvuloplasty (BMV). Transesophageal echocardiography (TEE) done immediately after BMV (in the catheterization laboratory) detected a new atrial septal defect (ASD) in 46 (92%) patients. These measured 1 to 2 (mean 1.2 +/- 0.3) mm in diameter. Doppler color flow mapping guided the location of the ASD in most of the cases. A narrow jet of left-to-right shunt could be evaluated by pulsed Doppler studies. Velocity time integral (VTI) of the jet across one cardiac cycle and the diameter of the ASD were used to calculate the left-to-right shunt (shunt = VTI x pi (D/2)2 x heart rate). The estimated shunt was 0.04-0.39 (mean 0.20 +/- 0.10) L/minute. A repeat study at seventy-two hours revealed the defect in 40 (80%) patients. At three months, the defect persisted in only 5 (10%) cases. The mean interval of closure of ASD was 4.6 +/- 2.2 weeks. The authors conclude: (1) ASD occurs commonly after BMV, (2) the septal defect and the resultant left-to-right shunt are insignificant, and (3) ASD disappears in the majority of cases by three months after BMV.

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.

Sensitivity of contrast ultrasound in the detection of atrial septal defect with predominant left-to-right shunting

Ultrasound contrast techniques are used widely as a screening test for intracardiac shunt. We performed a retrospective analysis of contrast echocardiograms in 29 consecutive patients with atrial septal defect (excluding Eisenmenger's) proved by cardiac catheterization. A positive (right-to-left atrial) ultrasound contrast effect was seen in 25 patients in whom catheterization pulmonary-to-systemic flow rate (Qp/Qs) was 2.2 +/- 0.9 (SD). Four patients had false-negative contrast echocardiography results; their Qp/Qs was 2.9 +/- 0.4 (p = 0.07). The percent left-to-right shunt was higher in the group with false-negative contrast echocardiographic results (65% +/- 4% vs 47% +/- 21%) (p = 0.05). Shunts with Qp/Qs < or = 2.0 had a sensitivity of 100%, whereas those with Qp/Qs > or = 2.1 had a sensitivity of 73%. In the four false-negative contrast echocardiographic results, three had findings of an atrial septal defect by pulsed Doppler, color Doppler, or both. Thus the presence of a large left-to-right shunt may decrease the sensitivity of the ultrasound contrast technique for the detection of an atrial septal defect. Contrast ultrasonography should be used in conjunction with Doppler and two-dimensional echocardiography criteria for diagnosis of atrial septal defect.

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.

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.

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.

Initial clinical experience with a 48 by 48 element biplane transesophageal probe

Recent technologic advances in ultrasound have resulted in the capability of transesophageal echocardiographic imaging in both transverse and longitudinal planes. Previous biplane probes suffered from inferior images because of reduced scan elements. We evaluated the utility of a prototype 48 X 48 element biplane transesophageal probe in 23 consecutive patients. Examinations were well tolerated with no side effects. In comparison to the single transverse plane, imaging with the longitudinal plane gave superior information on prosthetic valve pathology, atrial septal abnormalities, and pathoanatomy of the ascending aorta and mitral valve. Complementary information was provided by the longitudinal plane in patients with endocarditis and vegetations and in mitral protheses. Images obtained with this 48 X 48 element biplane probe along with color and spectral Doppler information were not perceptibly inferior to those obtained by single-plane probes. In conclusion, biplane transesophageal echocardiography with a 48 X 48 element probe indicates a great potential for enhanced three-dimensional understanding of cardiac pathology and diagnostic yield in specific pathologies.

Value and limitations of color Doppler echocardiography in the evaluation of percutaneous balloon mitral valvuloplasty for isolated mitral stenosis

The limitations of 2-dimensional and pulsed Doppler echocardiography in patients undergoing mitral valvuloplasty are well known. This study was undertaken to assess the value of color Doppler flow imaging in 36 symptomatic mitral stenosis patients who subsequently underwent successful balloon mitral valvuloplasty by comparing the results to those obtained at cardiac catheterization. Color Doppler-guided conventional Doppler assessment agreed well with cardiac catheterization results in classifying mitral stenosis as mild, moderately severe and severe, both before and after valvuloplasty. Color Doppler was also useful in identifying patients who had moderate to severe mitral regurgitation before and after valvuloplasty. Color Doppler flow mapping was more sensitive than oximetry in the detection of iatrogenic atrial septal defects, which were noted in 25 patients. The defects of those patients with smaller defects by color Doppler (diameter less than 0.7 cm) or echocardiographic shunt volume less than 0.7 liters/min tended to close, usually within 6 months, as opposed to those with larger defects or higher shunt volumes, which tended to persist. Echocardiographic shunt volumes revealed a fair correlation with oximetric results.

Transesophageal biplane echocardiographic imaging: technique, planes, and clinical usefulness

The technique of examination, imaging planes, and the clinical utility of transesophageal biplane echocardiography are described.