Monoplane Transesophageal Echocardiography Research Articles

Effects of hemodynamic monitoring using a single-use transesophageal echocardiography probe in critically ill patients \u2013 study protocol for a randomized controlled trial

BackgroundHemodynamic instability is one of the leading causes of intensive care unit (ICU) admission. Early stabilization of hemodynamics is associated with improved outcome. The monitoring used to guide hemodynamic support may influence the time needed to achieve stable hemodynamics. Visualization of the heart using echocardiography offers the advantage of direct measurement of cardiac volumes and ventricular function. A miniaturized monoplane transesophageal echocardiography (TEE) probe was developed, allowing for almost continuous qualitative hemodynamic TEE assessment (hTEE) after brief bedside training. The primary objective of the study is to assess whether hemodynamic monitoring using the hTEE technology shortens time to resolution of shock in ICU patients in comparison to standard monitoring using a central venous catheter, pulmonary artery catheter, or conventional echocardiography.MethodsFive hundred consecutive subjects with circulatory shock (low mean arterial blood pressure (MAP) and signs of organ hypoperfusion) at the time of ICU admission are included in the study. The subjects are randomly assigned to one of four groups using a 2 × 2 factorial design stratified by method of hemodynamic monitoring (hTEE vs standard hemodynamic monitoring) and frequency of hemodynamic assessments (minimum every 4 h vs standard of care). The primary study outcome is the time from study inclusion to resolution of circulatory shock, defined as MAP > 60 mmHg for ≥ 4 h after discontinuation of vasopressors and inotropes. The hTEE monitoring consists of the acquisition of three defined echocardiography views: Transgastric mid-esophageal short axis with measurement of fractional area change of left ventricle, mid-esophageal four-chamber view with measurement of the ratio of right to left ventricular area, and mid-esophageal ascending aortic short-axis view with measurement of the superior vena cava collapsibility index. In the control groups, monitoring modalities, including conventional TTE and TEE but not hTEE, are at the discretion of the treating physician. The interpretation of hemodynamic monitoring and the subsequent changes in patient management are recorded after each hemodynamic assessment. Differences in the primary and further secondary time-to-event outcomes will be assessed using a competing risk model accounting for the competing risk of death.DiscussionThe effect of using echocardiography as a monitoring modality on relevant patient outcomes has not been established so far. The study at hand may be one of the first trials to provide detailed data on effectiveness and safety of echocardiography to guide treatment in patients with circulatory shock.Trial registrationClinicalTrials.gov, ID: NCT02048566. Registered on January 29, 2014.

Initial clinical experience with a miniaturized transesophageal echocardiography probe in a cardiac intensive care unit.

To investigate the safety of a novel, miniaturized, monoplane transesophageal echocardiography probe (mTEE) and its potential as a hemodynamic monitoring tool. This was a retrospective analysis of the clinical evaluation of a disposable mTEE in ventilated patients with severe cardiogenic shock requiring hemodynamic support. mTEE assessment was performed by operators with mixed levels of TEE training. Information on hemodynamic interventions based on mTEE findings was recorded. A tertiary university cardiac critical care unit. Male and female critical care patients admitted to the unit with severe hemodynamic instability. Insertion of miniaturized disposable TEE probe and hemodynamic and other critical care interventions based on this and conventional monitoring. In 41 patients (51.2% female, 73.2% after cardiac surgery), hemodynamic support probe insertion was accomplished without major complications. A total of 195 mTEE studies were performed, resulting in changes in therapy in 37 (90.2%) patients based on mTEE findings, leading to an improvement in hemodynamic parameters in 33 (80.5%) patients. Right ventricular (RV) failure was diagnosed in 25 patients (67.6%) and mTEE had a direct therapeutic impact on management of RV failure in 17 patients (68 %). Insertion and operation of a novel, miniaturized transoesophageal echocardiography probe can be performed for up to 72 hours without major complications. Repeated assessment using this device provides complementary information to invasive monitoring in the majority of patients and has an impact on hemodynamic management.

Right Ventricular Dysfunction in Sepsis

Current Surviving Sepsis Campaign guidelines inadequately address the limitations of central venous pressure monitoring, which are due, in part, to right and left ventricular dysfunction associated with sepsis. Septic cardiomyopathy is well described in the literature but is both underrecognized and undertreated clinically. Direct cardiac assessment with transesophageal echocardiography (TEE) has documented advantages, but is limited by single evaluations and the need for advanced training. Recently, a disposable, monoplane TEE probe that provides for serial echocardiographic assessments in unstable patients to guide medical management, or hemodynamic TEE (hTEE), has been introduced. This article reviews a case of a 48-year-old gentleman with a history of smoking, chronic obstructive pulmonary disease, and Child’s A cirrhosis who underwent an uneventful off-pump coronary artery bypass grafting and 2 days later developed septic shock from pneumonia complicated by right ventricular dysfunction. hTEE provided a rational guide to fluid resuscitation, vasopressor, and inotropic therapy with ensuing patient convalescence. Although there is a lack of hTEE experience among current intensivists, there is a desire to learn echocardiography as witnessed by the success of echocardiography courses and interest among critical care fellows. Future work to assess echocardiographic hemodynamic protocols and their effect on outcomes will be important.

A Novel Scoring System May Predict Neurologic Non-Survival at 24Hours during Therapeutic Hypothermia Following Out of Hospital Cardiac Arrest: A Retrospective Review

Introduction: This investigation summarizes initial data which indicates neurologic outcome may be predicted during therapeutic hypothermic treatment following out of hospital cardiac arrest by using clinical observation of four risk factors assessed within the first 24 hours following ICU admission. Methods: In this retrospective, observational study conducted at a tertiary care university hospital, we retrospectively reviewed the medical records of 13 consecutive patients undergoing therapeutic hypothermia following out of hospital cardiac arrest in which a novel disposable monoplane Transesophageal Echocardiography probeClariTEE™ (Imacor Inc., Garden City ,NY, USA) was placed to observe myocardial recovery. During the first 24 hours following ICU admission the seven neurological non-survivors displayed 2 or more of the following risk factors: Bispectral Index < 40 (8-24 hours), arterial pH < 7.34 (12- 20 hours), best left ventricular fractional area of change < 25% (0-24 hours), and right ventricular dysfunction of at least moderate severity (0-24 hours). The six neurological survivors displayed 0 or only 1 of these risk factors. The presence of 2 or more risk factors thus predicted neurologic non-survival with a 100% sensitivity (95% CI: 0.56-1 due to small sample size) and 100% specificity (95% CI: 0.52-1 due to small sample size), p=0.0006. Statistical significance was calculated with the most conservative appropriate test, Fisher’s two-tailed exact test. Conclusions: This preliminary evidence suggests that a prognostic scoring system consisting of bispectral index, echocardiographic evaluation of right and left ventricular function, and arterial pH obtained within the first 24 hours of ICU admission may predict neurologic non-survival in patients undergoing therapeutic hypothermia following out of hospital cardiac arrest. Multimodal prognostic scoring systems may serve to identify patients whom would benefit most from intensive therapy.

Initial Experience with a Disposable Transesophageal Echocardiography Monitoring System during Therapeutic Hypothermia following out of Hospital Cardiac Arrest

Objective: This investigation summarizes the initial clinical experience of trained echocardiographers who utilized a miniaturized disposable monoplane transesophageal echocardiography (TEE) system in patients undergoing therapeutic hypothermia following out of hospital cardiac arrest.Design: A retrospective, single-center, observational study. Setting: A tertiary care university hospital.Patients: We retrospectively reviewed the medical records of 13 consecutive patients undergoing therapeutic hypothermia following out of hospital cardiac arrest in which a disposable monoplane TEE probe was placed to observe myocardial recovery and potentially guide hemodynamic optimization. Measurements and Main Results: A total of 40 imaging sessions were performed. The success rate for obtaining the mid-esophageal four chamber and the transgastric mid-papillary short axis views were 92.5% and 100% respectively. Endocardial border definition was adequate in 90% of imaging sessions to measure left ventricular end diastolic and systolic areas enabling calculation of fractional area of change. Assessment of right ventricular function was possible in 92.5% of imaging sessions.A significant number of imaging sessions (12/40, 30%) provided information that clarified the patient’s biventricular function in the setting of ambiguous invasive pressure monitoring measurements.Conclusions: Acquisition of a mid esophageal four chamber and transgastric mid papillary view was possible with the miniaturized disposable TEE probe in the vast majority of imaging sessions. This information enabled the qualitative assessment of right ventricular function, measurement of left ventricular end systolic, and diastolic area with a high degree of success in patients during therapeutic hypothermia following cardiac arrest. The authors postulate that serial assessment of biventricular function and filling with serial TEE imaging provides information that cannot be reliably inferred from other advanced hemodynamic monitoring devices in routine clinical practice. This work was funded by the Department of Anesthesiology at Vanderbilt University Medical Center.

Three-Dimensional Transesophageal Echocardiography Is a Major Advance for Intraoperative Clinical Management of Patients Undergoing Cardiac Surgery

Echocardiography is a key assessment tool for the evaluation of cardiac structure and function. The ability to image cardiac structures using 3-dimensional (3D) echocardiography is evolving. In this article, we present some of the key features of the emerging 3D technology and review its applications with an emphasis on real-time 3D transesophageal echocardiography.

Not All Perioperative Myocardial Infarctions Can Be Prevented with Preoperative Revascularization

Not All Perioperative Myocardial Infarctions Can Be Prevented with Preoperative Revascularization

Direct Current Cardioversion of Atrial Fibrillation—The Next 40 Years

Direct Current Cardioversion of Atrial Fibrillation—The Next 40 Years

Multiplane Transesophageal Echocardiographic Acquisition of Ascending Aortic Flow Velocities: A Comparison with Established Techniques

Acquisition of ascending aortic flow velocities with monoplane transesophageal echocardiography (TEE) have been problematic because of limitations of available imaging planes and alignment of the Doppler beam with aortic flow. The rotatable imaging array of multiplane TEE (Multi TEE) may provide improved alignment with ascending aortic blood flow. The purpose of this study was to establish the validity of maximal aortic flow velocities (VMax) and velocity time integrals (VTI) obtained by a Multi TEE continuous wave Doppler technique by comparison with those obtained by established echocardiographic techniques, suprasternal Doppler (SSD), and monoplane TEE (Mono TEE). Forty-five patients scheduled for elective surgery were prospectively studied. Multi TEE-obtained VMax and VTI were significantly greater ( P < .05), 120 ± 28.9 cm/s and 25.8 ± 7 cm, than those obtained by the SSD method, 100.2 ± 28.6 cm/s and 19.8 ± 6.8 cm, respectively. Bias analysis revealed that Multi TEE better assessed VMax (mean difference -19.7, SD of the difference of 28 cm/s) and VTI (mean difference -5.9, SD of the difference of 6.4 cm) than the SSD method. Multi TEE exhibited values for VMax 10% or greater than those obtained by SSD in 18 (48.6%) of 37 patients, and Multi TEE was 10% or greater than SSD in 23 (67%) of 37 patients for VTI determination. Values obtained by Multi TEE and Mono TEE showed close agreement. Multi TEE provides a favorable alignment for continuous wave Doppler interrogation of aortic flow and compared favorably to established techniques. This technique expands the utility of TEE to evaluate aortic valvular function and cardiac performance. (J Am Soc Echocardiogr 1999;12:754-60.)

Transnasal Transesophageal Echocardiography

In 42 endotracheally intubated patients, we examined the utility of a miniaturized monoplane probe for transnasal transesophageal echocardiography (TEE).Transnasal TEE was prospectively evaluated in 26 deeply and 16 mildly sedated patients receiving topical anesthesia with lidocaine jelly 2%. The patients with deep sedation were additionally examined with transoral monoplane and multiplane TEE. Transnasal esophageal insertion of the TEE probe was successfully performed in 90% of patients. Endotracheal malpositioning was corrected in two patients. nasal bleeding required treatment in another patient. Topical anesthesia was adequate in 82% of mildly sedated patients. Left ventricular short- and four-chamber long-axis views of good quality were obtained with transnasal (transoral) monoplane TEE in 76% (81%) and 92% (96%) of patients (differences not significant). Compared with conventional multiplane TEE, transnasal monoplane TEE missed diagnoses in 19% of patients. The relative error (mean +/- SEM) of quantification with transnasal TEE was <9% +/- 2% for ventricular diameters and <7% +/- 2% for cross-sectional area measurements, with a bias of 0.5 +/- 3.8 cm2 and 0.1 +/- 2.4 cm2 (mean +/- 2 SD) for left ventricular end-diastolic and end-systolic short-axis areas. The relative error in measuring intracardiac flow velocities was >40%, but systolic to diastolic peak velocity ratios at the valvular site were determined with an error <4% +/- 3%. Transnasal monoplane TEE can be performed even in mildly sedated patients with an endotracheal tube without further need for analgesia or sedation. The technique is as useful as conventional transoral TEE to image standard tomographic planes for quantification, but it is less suited for comprehensive echocardiographic diagnosing. Implications: Transnasal insertion of a miniaturized monoplane transesophageal echocardiography (TEE) probe was studied in endotracheally intubated patients. Nasal passage was well tolerated even by patients with only mild sedation. Imaging quality was similar to conventional transoral monoplane TEE with larger transducers, but technical restraints cause a deficit in complete cardiac diagnosing obtained with multiplane TEE. (Anesth Analg 1999;88:306-11)

Relative value of clinical and transesophageal echocardiographic variables for risk stratification in patients with infective endocarditis.

Infective endocarditis remains a life-threatening disease, and its optimal management is of paramount importance. Transesophageal echocardiography (TEE) is useful for the diagnosis of endocarditis-induced lesions, but the prognostic significance of the method remains controversial. The purpose of this study was to relate clinical and TEE characteristics to the occurrence of mortality and/or systemic embolization in a consecutive series of 45 patients with a diagnosis of infective endocarditis. All patients underwent at least one monoplane TEE. Clinical data, episodes of embolization, and echocardiographic characteristics were prospectively recorded. Stepwise logistic discriminant analysis was performed to identify the independent variables that best predicted three binary outcomes: systemic embolization, death, and systemic embolization and/or death. Twelve of the 45 patients (27%) died from the endocarditis. Significant univariate predictors of death were the presence of paravalvular abscess (p = 0.025), number of vegetations (p = 0.021), Staphylococcus aureus isolated in blood cultures (p = 0.002), medical treatment alone (p < 0.002), and systemic embolism (p < 0.001). In multivariate analysis, systemic embolism (chi 2 = 29.3; p < 0.01), echocardiographic evidence of paravalvular abscess (chi 2 = 5.6; p = 0.018), Staphylococcus aureus endocarditis (chi 2 = 5.5; p = 0.016), and medical treatment alone (chi 2 = 5.11; p = 0.024) emerged as optimal predictors of death. Systemic embolization occurred in 12 patients. Independent variables predicting systemic embolization were a total length of vegetations > 14 mm (p = 0.01), greater age (p = 0.02), and medical treatment alone (p = 0.03). When two or more vegetations were observed, the total length is the sum of the individual sizes. Independent risk factors for the development of systemic emboli and/or death as a combined end point were total length of vegetations on TEE (chi 2 = 6.4; p = 0.003) and medical treatment alone (chi 2 = 4.1; p = 0.047). High-risk patients may be identified by the combination of clinical variables and TEE characteristics.

Goal-directed transesophageal echocardiography performed by intensivists to assess left ventricular function: Comparison with pulmonary artery catheterization

Objectives: Transesophageal echocardiography (TEE) is a valuable procedure for assessing left ventricular (LV) function, but it has not been widely applied in critical care because of the limited number of intensivists who are trained in echocardiography. This prospective study was designed to evaluate the feasibility of training intensivists to perform a goal-directed, limited-scope TEE to assess LV function in critically ill patients using a pediatric monoplane TEE probe. A secondary goal was to compare the usefulness of the TEE data with that of data obtained by a simultaneous pulmonary artery catheter (PAC). Design: Prospective, blinded. Setting: University teaching hospital. Participants: One hundred consecutive, intubated, intensive care unit patients. Interventions: Five surgical intensivists with no previous background in echocardiography were trained under the supervision of two cardiologists to perform limited-scope TEE using a monoplane pediatric probe. One intensivist (A) reviewed the PAC data and recorded a diagnostic impression and therapeutic plan. A second intensivist (B), blinded to the PAC data, then performed TEE to determine cardiac volume, LV wall thickness, and LV global and regional wall motion. Intensivists A and B reviewed the data from both PAC and TEE, and intensivist A then formulated a new diagnosis and therapeutic plan. Measurements and Main Results: Intensivists performed 48 TEE examinations under direct supervision of a cardiologist, and 52 without supervision, but reviewed poststudy. The average duration of TEE was 12 ± 7 minutes. The intensivists' interpretations of TEE data were deemed correct in 93% of cases for LV wall thickness, 87% for intracardiac volume status, 81% for regional LV wall motion abnormalities, and 77% for global LV function. When the TEE and PAC technologies were compared, it was found that the TEE data disagreed with.the PAC evaluation of intracardiac volume in 55% of cases and with the PAC assessment of myocardial function in 39% of cases. The post-PAC therapeutic recommendations were different from the post-TEE therapeutic recommendations in 58% of patients. Conclusions: Training intensivists in limited-scope, goal-directed TEE, using a pediatric monoplane probe to evaluate LV function, can be done rapidly and safely, and yield data pertinent to management of critically ill patients even in the early stages of skill acquisition.

Intraoperative Transesophageal Echocardiographic Assessment of Vascular Anastomoses in Lung Transplantation: A Report on 18 Cases

<h3>Background</h3> In patients after lung transplantation, dysfunction of pulmonary venous and artery anastomoses leading to reoperation is described. <h3>Methods and results</h3> Pulmonary artery and vein anastomoses were evaluated intraoperatively by monoplane transesophageal echocardiography (TEE) in 18 patients undergoing lung transplantation (nine right, five left single lung transplantations, and four bilateral transplantations). All 13 right pulmonary artery anastomoses and all 22 pulmonary vein anastomoses could be visualized by TEE. None of the nine left pulmonary anastomoses could be visualized. Of the 13 right pulmonary anastomoses, 12 were considered normal, their diameter ranging from 1 to 1.7 cm (mean, 1.26±0.24 cm). A moderate stenosis of one pulmonary artery anastomosis was identified but did not require reoperation. Of the 22 pulmonary vein anastomoses, 16 were considered normal, their diameter being >0.5 cm and the peak systolic flow velocity ≤1 m/s at the location of the anastomoses. In five cases, the anastomoses were not considered normal, but reoperation was not indicated. In one case, a severe stenosis of pulmonary vein associated with graft dysfunction led to an early reoperation. <h3>Conclusion</h3> Intraoperative TEE during lung transplantation contributes to the immediate evaluation of pulmonary vein and right pulmonary artery anastomoses and allows immediate surgical correction. Further investigations are necessary to establish threshold values requiring reoperation.

Usefulness of multiplane transesophageal echocardiography to improve the assessment of severity of mitral regurgitation

This study was designed to examine the accuracy of multiplane transesophageal echocardiography (TEE) color Doppler measurements in comparison to monoplane or biplane measurements in estimating the severity of mitral regurgitation (MR). Multiplane TEE potentially increases diagnostic accuracy of transesophageal examinations; it is unknown if multiplane is more accurate in assessing the severity of MR than monoplane or biplane TEE. Left ventricular cineangiograms of 91 patients with MR (40 no or mild, 30 moderate, and 21 severe) were compared with systolic pulmonary venous flow reversal and transesophageal color Doppler measurements: jet area and length in the transverse and longitudinal plane, maximal and average of those 2 planes (biplane), and maximal and average of 11 different planes (multiplane). Flow reversal (16 patients) identified severe MR with a specificity of 96% and a sensitivity of 62%; these were 96% and only 10% to 43%, respectively, for color Doppler measurements. In the absence of flow reversal, multiplane maximal jet area predicted severe MR with a sensitivity of 88% and a specificity of 75%, which were 85% and 76%, respectively, for no or mild MR; this did not differ significantly from results obtained by monoplane or biplane measurements. Color Doppler measurements of eccentric jets were not reliable for identification of severe MR. Systolic pulmonary venous flow reversal identifies 2 of 3 patients with severe MR with a high accuracy. In patients without flow reversal, multiplane color Doppler TEE is very capable of assessing MR severity, but biplane and monoplane TEE are equally accurate.

False-positive diagnosis of ascending aorta dissection by single-plane transesophageal echocardiography

Acute descending thoracic aorta dissection was diagnosed on the basis of a contrast computed tomographic scan in a 72-year-old hypertensive man with acute chest pain. At physical examination, the patient was in stable condition, all pulses were present, arterial pressure was 180/85 mm Hg, and a mild aortic diastolic murmur was audible. Electrocardiography showed a 62 beat/min normal sinus rhythm, with no signs of ischemia. Chest radiography showed a moderate mediastinal enlargement. At contrast computed tomographic scan, the descending thoracic aorta showed the signs of acute dissection, with a false lumen with low flow inside evidenced by poor opacification and without evidence of reentry. The transverse aorta was not well visualized, and it was not possible to detect the upper limit of the dissection. The ascending aorta appeared dilated, but no intimal flap could be identified. We decided to perform transesophageal echocardiography (TEE). We used the Aloka MNI-0260-2, 5 MHz monoplanar transducer (Aloka, Co., Ltd., Tokyo, Japan), which showed an important dissection extending from the innominate artery into the ascending aorta. The ascending aorta appeared dilated, and a flap could be seen above the aortic valve (Fig. 1). No intimal tear was seen, suggesting a retrograde dissection mechanism. Mild aortic valve regurgitation was also noted, and no pericardial effusion was seen. Monoplanar TEE confirmed the presence of a dissection with low flow within the false lumen in the descending thoracic aorta. Because of the dramatic aspect of the lesion and the suspicion of a retrograde dissection of ascending and transverse aorta, we decided to operate on the patient without delay. A median sternotomy was decided on because of the involvement of the ascending aorta in the dissection. The left common femoral artery was prepared, and the cervical region was included in the operative field. Intraoperative inspection showed a moderately dilated ascending aorta with neither hematoma nor aortic wall abnormality. When the aortic arch was completely exposed, no signs of dissection were detected along the

The effect of technical factors on the quality of pulmonary venous flow from the transverse and longitudinal imaging planes with transesophageal echocardiography

Right and left upper pulmonary venous flow is usually assessed with monoplane transesophageal echocardiography (TEE) in the transverse imaging plane. Pulmonary venous flow in the transverse imaging plane may be relatively difficult to record because of the larger angle between the pulmonary vein and the transducer beam. To compare the quality of echocardiographically derived Doppler flows of the right and left upper pulmonary veins between the longitudinal and transverse imaging planes with TEE, we performed pulsed-wave Doppler TEE of both upper pulmonary veins in transverse and longitudinal imaging planes in 36 patients with various diseases. We also recorded a quality index for each flow profile and the angle between the transducer beam and the pulmonary vein. The quality index of the left pulmonary venous flow assessed with the longitudinal and transverse imaging planes was similar in 35 (95%) of 36 patients, whereas the longitudinal imaging plane was superior to the transverse plane in one patient (3%). In contrast, the quality index of the right pulmonary venous flow assessed with the longitudinal and transverse imaging planes was similar in only 19 (53%) of 36 patients, whereas in 17 patients (47%) the longitudinal imaging plane was superior to the transverse imaging plane. The quality index had a significant effect on the Doppler flow recordings; suboptimal-quality flow recordings significantly underestimated the pulmonary venous diastolic flow integrals. The left atrium was larger in those patients with unobtainable flows than in those patients with exclusively obtainable flows (p < 0.001). The angle between the sample volume and the right pulmonary vein was larger in the transverse imaging plane than in the longitudinal plane (p < 0.001). In conclusion, the longitudinal imaging plane is generally superior to the transverse imaging plane for assessing right pulmonary venous flow and is recommended for performing a comprehensive assessment of pulmonary venous flow. The ability to obtain quality images and accurate assessment of flow may be related to the size of the left atrium and angle of the pulmonary vein.

Diagnostic Accuracy of Transesophageal Echocardiography for Detecting Patent Ductus Arteriosus in Adolescents and Adults

To compare the accuracy of transesophageal echocardiography (TEE) with that of transthoracic echocardiography (TTE) in the detection of patent ductus arteriosus (PDA) in the adolescent and the adult, 40 patients with PDA and 50 patients with other congenital heart diseases were studied. All echocardiograms were recorded before cardiac catheterization and surgery. The echocardiographic diagnosis of PDA was made by direct visualization of a shunt flow in the duct. A mosaic flow in the pulmonary artery without direct visualization of the duct was considered possible but not definitely diagnostic of PDA. TEE showed greater sensitivity and negative predictive value than TTE (97% vs 42%, and 98% vs 68%, respectively; p < 0.001) in confirming the diagnosis of PDA. The specificity and positive predictive value in establishing the diagnosis of PDA were the same for both techniques. In the subgroup of patients with Eisenmenger's syndrome, the sensitivity of TEE and TTE in confirming diagnosis of PDA was 100% and 12% (p < 0.01), respectively. The sensitivity of monoplane and biplane TEE in the diagnosis of PDA was comparable (95% and 100%, respectively; p = NS). In conclusion, TEE was highly sensitive and specific in detecting PDA in adolescents and adults. It was also highly valuable for detecting the cause of pulmonary hypertension in patients with Eisenmenger's syndrome.

Intraoperative validation of mitral inflow determination by transesophageal echocardiography: Comparison of single-plane, biplane and thermodilution techniques

This study investigated the accuracy of mitral inflow quantification using biplane transesophageal echocardiography. Mitral stroke volume can be reliably quantified by transthoracic Doppler echocardiography, but previous studies involving monoplane transesophageal echocardiography have yielded mixed results. Thirty patients without mitral regurgitation were prospectively examined immediately before cardiovascular surgery. Mitral annulus diameter was measured in the transverse (d1) and longitudinal views (d2) by biplane transesophageal echocardiography. Assuming an elliptic shape, the annular area was calculated as pi d1d2/4; area was also calculated from single-plane data assuming a circular annular shape as pi d2/4. The time-velocity integral of mitral annular Doppler velocity was then multiplied by annular area to yield stroke volume. These data were compared with simultaneous thermodilution measurements by linear regression. Good correlations were observed between thermodilution (x) and Doppler (y) measurements of stroke volume (SV) (r = 0.86, p < 0.01, delta SV [y-x] = 2.64 +/- 9.86 ml for single four-chamber view; r = 0.77, p < 0.01, delta SV = 1.82 +/- 12.59 ml for two-chamber view; r = 0.94, p < 0.001, delta SV = 1.78 +/- 5.90 ml for biplane measurements) with similar data for cardiac output (r = 0.82, r = 0.74 and r = 0.92, respectively). The biplane measurements were most accurate and had less variability in individual patients (p < 0.05). This finding was supported by a numerical model that demonstrated (for an ellipse of eccentricity 1.5:1) that even maximal misalignment of biplane diameters yielded only 8% area overestimation, whereas single-plane calculations assuming a circular shape produced a variation in area of 225%. This study validates the accuracy of measurements of mitral inflow using biplane transesophageal echocardiography with potential application for quantification of valvular regurgitation in the operating room. The results are further generalizable, indicating that orthogonal biplane measurements are both necessary and sufficient to ensure accuracy in area calculation for any elliptic structure.

The Incidence of Patent Foramen Ovale in 1,000 Consecutive Patients: A Contrast Transesophageal Echocardiography Study

Patent foramen ovale (PFO) is present in 10 to 35% of people and has been reported to be an important risk factor for cardioembolic cerebrovascular accidents (CVAs) and transient ischemic attacks (TIAs), especially in younger patients. While contrast transthoracic echocardiography has been used to detect PFO, contrast transesophageal echocardiography (TEE) has a greater sensitivity. Prior studies reported the incidence of PFO in patients presenting with a CVA or TIA. To determine the incidence of PFO in a more general population, we reviewed 1,000 consecutive TEEs performed with contrast and color Doppler for the presence of PFO and other cardioembolic risk factors, including atrial septal aneurysm (ASA), aortic plaque, atrial fibrillation (AFib), and atrial thrombi. While imaging with monoplane or biplane TEE, multiple injections of agitated saline solution were injected during cough or Valsalva maneuver to detect flow through a PFO. There were 482 male and 518 female patients with mean age of 60 +/- 17 years (range 11 to 93 years). Patent foramen ovale was found in 9.2% of all patients and, though seen in all age groups divided by decade, the incidence in patients aged 40 to 49 years was greater than those aged 70 to 79 years (12.96% vs 6.15%, p = 0.03). Contrast TEE had a much higher detection rate than color Doppler alone. Importantly, there was no greater incidence of PFO in patients with CVA vs those without CVA, or in male vs female patients. Also, there was a very strong correlation between the presence of ASA and PFO (p < .001). Thus, PFO detected by TEE, frequently seen with ASA, is seen in all age groups and does not in itself present a risk factor for CVA. The association of PFO with peripheral thrombosis and CVA needs further study.

Left atrial-volume determination by echocardiography. Validation by biplane angiography in the setting of mitral balloon valvuloplasty.

To validate echocardiographic left atrial volume measurements, 25 patients with mitral stenosis were studied before and after mitral balloon valvuloplasty. Seven normals served as controls. The modified Simpson's rule was used for echocardiographic and angiographic left atrial volume determination from two orthogonal planes. Left atrial antero-posterior diameter was measured from parasternal long axis view and supero-inferior and medio-lateral diameters from apical four-chamber view. Transthoracic echocardiographic left atrial volume correlated well, but systematically underestimated angiographic left atrial volume (y = 0.4x + 27, r = 0.92). Monoplane transesophageal echocardiography did not improve correlation, nor the underestimation. Out of the several left atrial diameters, antero-posterior dimension showed the closest correlation with angiographic volume (r = 0.91), which persisted after exclusion of patients with atria > 400 ml (r = 0.84). Furthermore, relative changes of antero-posterior diameter after mitral valvuloplasty were closely related to the relative changes observed in left atrial volume (r = 0.82). Our results suggest that, in spite of a consistent underestimation, bidimensional, transthoracic echocardiographic and angiographic left atrial assessment correlate closely. Moreover, it is suggested that the mere antero-posterior diameter from transthoracic two-dimensional image is sufficient in clinical practice for routine follow-op of left atrial volume.