Multiplane Probe Research Articles

Successful removal of migrated acupuncture needles in a patient with cardiac tamponade by means of intraoperative transesophageal echocardiographic assistance

Clinical Summary A 49-year-old woman was admitted to our hospital after having chest pain and was then hospitalized 2 hours later after syncope. She had a history of recurrent episodes of pulmonary thromboembolism that arose from deep vein thrombosis. A Bird’s Nest filter (Cook Co, Leechburg, Pa) was implanted in her inferior vena cava for the prevention of embolism about 6 years ago. Four weeks before admission, she felt bilateral shoulder pain and subsequently received acupuncture treatments to relieve the pain. She was treated with acupuncture on her shoulder and upper back 2 hours before symptom onset. Her blood pressure was 70/48 mm Hg in the emergency department, where a transthoracic echocardiogram showed a large amount of pericardial effusion with tamponade features. After detecting fine and linear foreign material sized approximately 5 cm penetrating the interventricular septum and right ventricular wall (Figure 1, A), a pericardiocentesis was immediately performed. After draining about 600 mL of fresh blood from the pericardial cavity, blood pressure was normalized. The foreign material was seen in the fluoroscopic and computed tomographic examinations (Figure 1, B and C); however, there was no evidence of migration of Bird’s Nest filter (Cook Inc, Bloomington, Ind). The emergency cardiac operation was done to remove the foreign bodies with intraoperative transesophageal echocardiographic guidance (Sonos 2000; Hewlett-Packard Co, Andover, Mass) with a multiplane probe. The transesophageal echocardiogram showed a needle-shaped mass crossing the interventricular septum. After the pericardiectomy, the needle-shaped foreign material was seen penetrating the right ventricular wall and was removed successfully. Despite of the removal, an intraoperative transesophageal echocardiography revealed another needle-shaped foreign body crossing from the interventricular septum to the left ventricular cavity (Figure 2, A). After a cardiopulmonary bypass, her left atrium was opened, and the foreign body was successfully removed. The removed foreign bodies were thin, needle-shaped materials (Figure 2, B). The materials were proved to be acupuncture needles after a comprehensive analysis from the Department of Acupuncture, College of Oriental Medicine, Kyung Hee University and the Department of Biomedical Engineering, Inje University. She was discharged after the operation without any complication.

Application of a Miniaturized Biplane Transesophageal Echocardiographic Probe in Adults

Background. Standard multiplane transesophageal echocardiographic probes have large transducer tips that could increase patient discomfort, especially during esophageal intubation. A miniaturized biplane probe has been developed for pediatric use; however, its utility for adult patients is unknown.Methods. The miniaturized biplane imaging was tested in 48 anesthetized, ventilated adult patients during cardiac surgery and was compared with the standard multiplane imaging. We evaluated the image quality of cardiac structures and thoracic aorta using a five-grade scoring system. We also measured the left ventricular end-diastolic dimension (LVEDD, mm) and the peak flow velocity (cm/s) of the left atrial appendage (LAA) by pulsed-wave Doppler.Results. Esophageal intubation with the multiplane probe was unsuccessful in 1 patient, although this patient was successfully intubated with the biplane probe. There were no complications with either probe. The image qualities of the left ventricle, mitral valve, aortic valve, and ascending aorta by the biplane probe were inferior to those by the multiplane one. On the other hand, left atrium (LA), LAA, interatrial septum, aortic arch, and descending aorta were as well visualized by the biplane probe as by the multiplane one. The values of LVEDD and peak flow velocity of LAA were not different between the probes. LAA thrombus in 2 of 47 patients and aortic dissection (Stanford type A) in 7 were also well detected by both methods.Conclusions. The resolution of the two-dimensional images in the near fields of the miniaturized biplane probe was as good as the standard multiplane one. The miniaturized biplane probe was found to be applicable to the detection of LA or LAA thrombus and assessment of LAA function in adults.

Two-dimensional and Doppler transesophageal echocardiographic delineation and flow characterization of anomalous coronary arteries in adults

Objectives The purpose of this study was to examine the use of transesophageal echocardiography (TEE) in the identification and flow characterization of congenital coronary anomalies. Background Congenital coronary anomalies in adults are rare but may cause serious cardiac complications. The use of TEE in evaluation of this entity has not been well defined. Very little is known regarding flow patterns in anomalous coronaries assessed by Doppler TEE. Methods A total of 32 consecutive adult patients were studied using TEE to define the origin, course, and proximal flow pattern of suspected coronary anomalies. Results Coronary anomalies identified using TEE included anomalous origin from the pulmonary trunk (n = 2), right sinus (n = 18), left sinus (n = 9), single coronary (n = 2), and left main coronary fistula (n = 1). Multiplane TEE performed in 20 cases simplified the delineation of more complex coronary anomalies. The origin was identified in all patients, proximal course delineated in 31, and proximal flow pattern characterized by pulsed Doppler in 23 of 32 patients. In 16 anomalous left main, left anterior descending, or left circumflex coronary arteries, an abnormal systolic flow pattern (ie, systolic/diastolic time-velocity integral ratio >1) occurred exclusively ( P < .001) when the anomalous artery had an intermediate (100%; 5/5) versus anterior or posterior course (0%; 0/11) relative to the aortic and pulmonary artery trunks. A systolic flow pattern was also evident in 4 (80%) of 5 patients with an anomalous right coronary artery with an intermediate course. Conclusions TEE, particularly with a multiplane probe, has an important complementary role to coronary angiography in delineating the proximal course and pattern of flow in anomalous coronaries. Predominant systolic flow pattern in anatomically left proximal anomalous coronaries signifies an intermediate course between the aorta and the pulmonary trunk and may be clinically useful for risk stratification.

Hemodynamic Instability in Sepsis

Septic shock is associated with important hemodynamic alterations, including absolute or relative decrease in central blood volume (1), systolic alterations of left ventricular (LV) (2, 3) and right ventricular (RV) (4) function, and severe peripheral vasodilatation responsible in part for alterations in regional blood flow distribution and probably linked to outcome (5). Hemodynamic treatment of septic shock requires blood volume expansion, which has proved to enhance survival if not delayed (6), and vasoactive support with catecholamines, according to the hemodynamic status (7). For a long time, assessment of hemodynamic instability in sepsis was based on right heart catheterization at the bedside. Recently, the Task Force of the American College of Critical Care Medicine reiterated the usefulness of right heart catheterization in guiding hemodynamic support in patients requiring more than an initial blood volume expansion (7). Concerns about the data obtained by this technique, and their interpretation in a mechanically ventilated patient, are not new (8). Moreover, this technique has been criticized for its invasiveness and associated specific complications (9). However, large cooperative clinical trials have not demonstrated an increase in mortality carried by right heart catheterization (10, 11). We abandoned right heart catheterization in our unit in 1990 and have replaced it by routine echocardiography. Since then, all patients hospitalized with septic shock have been monitored using echocardiography as a noninvasive bedside procedure. In our daily practice, echocardiography is performed after physical examination in all hemodynamically unstable patients and repeated immediately after each major hemodynamic intervention. For this purpose, the frozen multiplane probe can be kept in the esophagus for the time needed to assess the results of a major hemodynamic intervention (10–20 minutes). This strategy is original, few French teams use it, and no trial has demonstrated the usefulness of echocardiography in severe sepsis. But the quality of the data obtained and the growing demand for training from intensivists have convinced us that this procedure will be widely used in the future. Data from echocardiographic evaluation of a series of 183 patients have been published, emphasizing that a large spectrum of changes in ventricular systolic function can be observed in

Feasibility of transesophageal echocardiography with a ten-french monoplane probe

Objectives We examined the feasibility of transesophageal echocardiography (TEE) using a 10F monoplane probe developed for intracardiac ultrasound (AcuNav, Acuson/Siemens, Mountain View, Calif). Background Traditional TEE uses a 10- to 12-mm–diameter probe, and conscious sedation is customary to minimize patient discomfort. Because of its small size (3.2-mm diameter), the 10F monoplane probe can be inserted into the esophagus using only topical anesthesia. This provides the potential for a more easily tolerated examination. Methods A total of 20 patients underwent a comprehensive TEE using an adult multiplane probe. Immediately afterward, the 10F monoplane probe was inserted into the esophagus and a targeted examination completed. The 10F monoplane studies were blindly reviewed by 3 observers for the study indication and for 16 diagnostic elements. These were graded against an expert’s review of standard TEE. Results The 10F monoplane probe was well tolerated in all patients. Observers A, B, and C answered the clinical question in 80%, 85%, and 100%, respectively, with the 10F probe. The percentage of clinical elements deemed evaluable was 71%, 78%, and 80%, respectively. Limitations included incomplete visualization of the mitral valve and a systematic underestimation of the severity of valve regurgitation. Conclusions The 10F monoplane probe is safe, well-tolerated, and capable of evaluating many clinical questions. Because of its small size, conscious sedation may not be necessary. It may be useful for targeted evaluations, for monitoring invasive procedures, or for intermediate or long-term monitoring in an intensive care department.

Surface Integration of Velocity Vectors from 3D Digital Colour Doppler: An Angle Independent Method for Laminar Flow Measurements

Background: The study was designed to test the angle independence of a dynamic three-dimensional digital colour Doppler method for laminar flow measurement. The technique acquired three-dimensional data by rotational acquisition and used surface integration of Doppler vector velocities and flow areas in time and space for flow computation. Method: A series of pulsatile flows (peak flow 55–180 ml/s) through a curved tube were studied with reference flow rates obtained using an ultrasonic flow meter. Colour Doppler imaging was performed at three angles to the direction of flow (20°, 30°, 40°), using a multiplane transoesophageal probe controlled by an ATL HDI 5000 system. Integration of digital velocity vectors over a curved three-dimensional surface across the tube for each of the 11 flow rates at each angle was performed off-line to compute peak flow. Results: Peak flow rates correlated closely (r=0·99) with the flow meter with the mean difference from the reference being −0·8±2·4 ml/s, 0·9±2·6 ml/s, 1·0±2·3 ml/s for 20°, 30° and 40° respectively. Comparison of the three angle groups showed no significant differences ( P =0·15, ANOVA). When sampled obliquely, the flow area on the curved surface increased while the velocities measured decreased. Conclusion: Surface integration of velocity vectors to compute three-dimensional Doppler flow data is less angle dependent than conventional Doppler methods.

A new dynamic three-dimensional digital color doppler method for quantification of pulmonary regurgitation: validation study in an animal model

ObjectivesThe purpose of the present study was to validate a newly developed three-dimensional (3D) digital color Doppler method for quantifying pulmonary regurgitation (PR), using an animal model of chronic PR. BackgroundSpectral Doppler methods cannot reliably be used to assess pulmonary regurgitation. MethodsIn eight sheep with surgically created PR, 27 different hemodynamic states were studied. Pulmonary and aortic electromagnetic (EM) probes and meters were used to provide reference right ventricular (RV) forward and pulmonary regurgitant stroke volumes. A multiplane transesophageal probe was placed directly on the RV and aimed at the RV outflow tract. Electrocardiogram-gated and rotational 3D scans were performed for acquiring dynamic 3D digital velocity data. After 3D digital Doppler data were transferred to a computer workstation, the RV forward and pulmonary regurgitant flow volumes were obtained by a program that computes the velocity vectors over a spherical surface perpendicular to the direction of scanning. ResultsPulmonary regurgitant volumes and RV forward stroke volumes computed by the 3D method correlated well with those by the EM method (r = 0.95, mean difference = 0.51 ± 1.89 ml/beat for the pulmonary regurgitant volume; and r = 0.91, mean difference = −0.22 ± 3.44 ml/beat for the RV stroke volume). As a result of these measurements, the regurgitant fractions derived by the 3D method agreed well with the reference data (r = 0.94, mean difference = 2.06 ± 6.11%). ConclusionsThe 3D digital color Doppler technique is a promising method for determining pulmonary regurgitant volumes and regurgitant fractions. It should have an important application in clinical settings.

Beating-heart mitral valve surgery: preliminary model and methodology.

It is our hypothesis that image-guided mitral valve repair can be performed on the beating heart without cardiopulmonary bypass. As a first phase, we tested the feasibility of suturing the anterior and posterior mitral valve leaflets under image guidance. In a water bath model, imaging approaches and suturing techniques were developed. Then, in 6 pigs, the left atrium was cannulated with a custom-made 15-mm valved port through a left thoracotomy. Atrial pressure was elevated by shunting of arterial blood to minimize air induction. A multiplane transesophageal echocardiographic probe was evaluated in the intraesophageal and epicardial positions. With a commercial endoscopic suturing device, sutures were placed through the anterior and posterior mitral leaflets under echocardiographic guidance. The animals were killed, and suture accuracy was evaluated by measuring the distance from the intended target areas on the anterior and posterior mitral leaflets. Air induction was monitored by echocardiography and graded as minimal to severe. There were no cases of hemodynamic instability or significant arrhythmia. The most effective imaging plane was a short-axis view that used the transesophageal echocardiographic probe epicardially at the heart base. Air induction was minimal in 2 animals, mild in 3, and moderate in 1. Sutures were successfully placed 9 of 12 times (mean error 0.8 +/- 0.5 cm). With these methods, off-pump, image-guided suturing of the beating-heart mitral valve was possible. This model may be a useful starting point for developing off-pump mitral valve repair procedures.

Quantitative Assessment of Aortic Stenosis by Three‐Dimensional Anyplane and Three‐Dimensional Volume‐Rendered Echocardiography

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

Transesophageal echocardiography in patients with recent stroke and normal carotid arteries

E of cardiac origin are the second most frequent cause of stroke. Transesophageal echocardiography (TEE) has been increasingly used to diagnose intracardiac thrombus as well as a number of other cardiac abnormalities. Evaluation of a suspected cardiac source of embolism is currently the most common indication for TEE in many centers because of transesophageal echocardiographic superiority over transthoracic echocardiography. The aim of the present prospective study was to evaluate the clinical significance of transesophageal echocardiographic findings in patients with normal carotid arteries who had suffered cerebral ischemia. • • • The study group consisted of 245 of the 458 patients referred to 3 institutions. Patients ranged in age from 36 to 86 years (mean 65.7 21); 77 were women and 168 were men (Table 1). All patients were selected on the basis of a recent unexplained cerebral ischemia and were included in the study if they had normal carotid arteries (group A). These patients were compared with 245 ageand sex-matched patients (mean age 64.7 23 years, range 29 to 86) who underwent transesophageal echocardiographic examination during the same period for indication other than cerebral ischemia (group B). Exclusion criteria were chronic atrial fibrillation, mitral prosthesis, and mitral stenosis. In group A, we excluded patients with evidence of a mass or hemorrhage on a computer tomographic head scan. In the study population (group A), a trained neurologist established a clinical diagnosis of transient ischemic attack or stroke. A computed tomographic scan (CT) was performed in all patients, and magnetic resonance imaging in 100 of the 245 patients. Cerebral ischemia was defined as: (1) stroke, sudden development of a permanent focal neurologic deficit after which a brain CT scan establishes a cerebrovascular accident as the cause; (2) reversible ischemic attack with complete or almost complete recovery without the need for therapeutic rehabilitation; (3) transient ischemic attack, which is completely resolved within 24 hours; and (4) reversible ischemic neurologic deficit in which there is full clinical recovery within 7 days. A cardioembolic source was suspected on clinical findings, brain imaging, and on normal duplex carotid ultrasound examination. All patients underwent complete transthoracic and transesophageal echocardiographic studies. In group A patients, the examinations were performed 1 to 7 days after the cerebral ischemic event. A Commercial Hewlett-Packard system (Andover, Massachusetts) with 2.5and 3.5-MHz probes and a 5-MHz biplane or multiplane frequency probe with color Doppler and spectral pulsed Doppler was used. Standard views from the gastric and lower esophageal windows were obtained from every patient. All patients who underwent TEE were given diazepam and pharyngeal xilocaine. Each study was assessed for the presence or absence of the following: left atrial enlargment, mass, thrombus, spontaneous echo-contrast, atrial septal defect, atrial septal aneurysm, patent foramen ovale (PFO), mitral annular calcium, mitral valve prolapse, vegetation or strands, left ventricular dilatation and dysfunction, and ascending aortic arch and descending aortic atherosclerotic plaque. Left atrial enlargment was diagnosed if the left atrial cavity was found to be 40 mm. Thrombus in the left atrium or appendage was defined as the presence of a clearly defined intracavitary mass acoustically distinct from underlying endocardium and not caused by the pectinate ridges of the left atrial appendage. Spontaneous echo contrast was defined as dynamic, smoke-like echoes with a characteristic swirling motion, distinct from the echoes caused by excessive gain. Gain controls had been adjusted optimally to minimize artifact by the physician performing the echo examination. Atrial septal aneurysm was defined as a bulge of 15 mm beyond the plane of the atrial septum as measured by TEE. Atrial septal aneurysm was classified according to Hanley’s diagnostic criteria, and modified by PearFrom the Department of Cardiology, Pierantoni Hospital, Forli; Department of Cardiology, University of Modena, Modena; and School of Medicine, University of Ferrara, Ferrara, Italy. Dr. Mattioli’s address is: Department of Cardiology, University of Modena, Via del pozzo 71, 41100 Modena, Italy. E-mail: mattioli.annavittoria@ unimo.it. Manuscript received February 19, 2001; revised manuscript received and accepted May 17, 2001.

Prospective study of routine perioperative transesophageal echocardiography for elective valve replacement: Clinical impact and cost-saving implications

Transesophageal echocardiography (TEE) is widely used during heart valve replacement operations, but its clinical impact and cost-saving profile have not been studied prospectively for this indication. We investigated the clinical benefits and cost-savings of routine TEE for elective valve replacement at a regional tertiary center. We prospectively studied 300 patients (140 men; mean age [±SD], 66 ± 9 years) undergoing aortic valve, mitral valve, or double-valve replacements. Transesophageal echocardiography with a biplane (in 161 patients) or a multiplane probe was performed before and after surgery. We assessed whether the TEE findings changed the operation or the postoperative treatment and the cost of TEE either as an extension of a preexisting service or as a new development. In 2 patients undergoing aortic valve replacement, significant mitral regurgitation on TEE led to additional mitral valve replacement, and in 1 patient undergoing mitral valve replacement, aortic regurgitation also required aortic valve replacement. Immediate reoperation (dehisced mitral valve prosthesis) and delayed extubation (suspected obstruction of an aortic valve prosthesis) were prompted by postoperative TEE. Extending an existing TEE service to routine intraoperative use saved up to $109 (US) per patient per year. Routine intraoperative TEE can provide major clinical benefit to a small proportion of patients undergoing elective valve replacement, and this can lead to cost savings, but only if the service can be provided without major capital investment. (J Am Soc Echocardiogr 2001;14:659-67.)

Influence of pneumoperitoneum and patient positioning on preload and splanchnic blood volume in laparoscopic surgery of the lower abdomen

Study Objective: To determine the hemodynamic effects of pneumoperitoneum and patient positioning during laparoscopic surgery of the lower abdomen. Design: Prospective study. Setting: University-affiliated medical center. Patients: 10 ASA physical I and II female patients scheduled for laparoscopic surgery of the lower abdomen. Interventions: Patients were anesthetized with propofol and an alfentanil infusion, then intubated, and normoventilated. Measurements: After intubation, a transesophageal multiplane probe for measurements of right (RVESA) and left (LVESA) ventricular end-systolic and end-diastolic areas (RVEDA and LVEDA) and ejection fraction area (RVEFa, LVEFa) was introduced; heart rate (HR) and noninvasive blood pressure (BP) were recorded every minute. Ventilation was not changed during the measurements. A transvaginal ultrasound probe was inserted to measure the diameter of the common iliac vein. Measurements were performed 15 minutes after induction of anesthesia and while patients were in the supine position (P 0), 10 minutes after CO 2 insufflation to 10 mmHg IA pressure (P 10), 10 minutes after a further increase to 15 mmHg (P 15), 10 minutes after 20° Trendelenburg (P 15 T), and 20° reverse Trendelenburg positions (P 15 RT). Data are shown as medians, 25th to 75th percentiles, and comparisons between P 0, P 10, P 15, and P15 T were made with the Friedman test, followed by Wilcoxon test, when significant. Data at P 15 T, P 15 RT, and P 15 were compared using the Wilcoxon test, with a p -value < 0.05 regarded as significant. Main Results: Pneumoperitoneum at 10 mmHg abdominal pressure caused a significant increase of LVESA by 78% (RVESA: 61%) and LVEDA by 48.5% (RVEDA: 45%). The diameter of the common iliac vein was decreased by 6%. A further increase of abdominal pressure to 15 mmHg led to an additional increase of 20% (LVESA) and 17% (LVEDA). Mean arterial pressure increased by a significant 7% at P 10, decreasing subsequently by 5% at P 15. The Trendelenburg position did not alter any hemodynamic findings. Reverse Trendelenburg position, however, caused a significant LVEDA–and RVEDA–decrease by 18% and 27%, respectively, and an increase in the diameter of the common iliac vein by 22%. The LVEFa and RVEFa decreased significantly after abdominal CO 2 insufflation by 18% each (P 10) without further change. Conclusions: The lithotomy position and subsequent pneumoperitoneum increased preload, probably as a result of blood shifting from the abdomen to the thorax by compression of splanchnic vessels caused by the pneumoperitoneum. Careful fluid management, maintaining low abdominal pressure, and use of the reverse Trendelenburg position are favored to prevent adverse hemodynamic effects in laparoscopic surgery.

Reply by the author

In a previous report on this study, 1 Blanker M.H. Groeneveld F.P.M.J. Prins A. et al. Strong effects of definition and nonresponse bias on prevalence rates of clinical benign prostatic hyperplasia the Krimpen study of male urogenital tract problems and general health status. BJU Int. 2000; 85: 665-671 Crossref PubMed Scopus (93) Google Scholar we provided a detailed description of the methods used to measure the prostate volume and postvoid residual urine volume. Transrectal ultrasonography of the prostate was performed using a 7-MHz Bruel & Kjaer multiplane sector scanning probe. The planimetric step-section technique was used to determine the prostate volumes. 2 Torp-Pedersen S. Juul N. Jakobsen H. Transrectal prostatic ultrasonography equipment, normal findings, benign hyperplasia and cancer. Scand J Urol Nephrol Suppl. 1988; 107: 19-25 PubMed Google Scholar The postvoid residual volume was computed by transabdominal ultrasound scanning using an Aloka machine with a 3.5-MHz handheld probe using the formula π/6 × (width) × (height) × (depth).One observer completed 86% of all transrectal ultrasound scans and postvoid residual volume measurements, and three other experienced observers performed the other 14%. Therefore, we do not think that interobserver variability is a reason for the lack of correlation between the prostate and postvoid residual urine volume and the FBC.

The role of echocardiography in transcatheter closure of atrial septal defects.

Closure of so-called "secundum" atrial septal defects with a device inserted on a catheter necessitates precise delineation of their morphology. Echocardiography is the diagnostic method of choice to demonstrate this morphology, and to differentiate such defects located within the oval fossa from the other variants producing an interatrial communication. Precordial echocardiography usually allows selection of cases likely to be suitable for closure in this fashion. This selection is based on the localisation and the size of the deficiency in the oval fossa, the length of the interatrial septum, and the adequacy of the infolded rims surrounding the defect. Suitability for closure is reevaluated by transesophageal echocardiography, either as a separate investigation or at the start of the interventional catheterisation. This investigation requires a multiplane transesophageal echocardiographic probe, since only oblique planes will demonstrate the entrance of the systemic and pulmonary veins and their relationship to the defect. Transesophageal echocardiography serves as an important monitoring tool during the interventional procedure. As such, it is a necessary adjunct to fluoroscopy. The stretched diameter of the defect measured with a balloon is the main determinant of the choice of the type and size of the device. This diameter can be measured fluoroscopically, as well as on echo. Colorflow mapping serves to rule out residual shunting during the occlusion of the defect with the balloon. During deployment of the device, constant echocardiographic visualisation of the device and its position relative to the atrial septum facilitates proper placement. Such constant visualisation can only be provided by repeated quick acquisitions of multiple planes. Once the device is released, the investigator should continue to record the position of the device, and assess the potential for residual shunting. Most of the devices show some subtle change in position during the first 20 minutes after implantation.

A digital 3-dimensional method for computing great artery flows: In vitro validation studies

Background: Conventional 2-dimensional Doppler large vessels are prone to inaccuracy. Three-dimensional (3D) volume imaging provides the opportunity to make cross-sectional flow calculations through digital spatiotemporal integration of flow velocity, area, and profile. Methods: A new digital 3D color Doppler reconstruction method was used to generate radially acquired flow data sets. Raw scanline data with digital velocity assignments, obtained by scanning parallel to flow, were transferred from a specially programmed but otherwise conventional ultrasonographic system, which controlled a multiplane transesophageal probe, to a computer workstation via an Ethernet link for assimilation into color 3D data sets. This configuration was used to study 20 pulsatile laminar flows (stroke volumes 30 to 70 mL and peak flow rates 65 to 205 mL/s) in a curved tube model with an oval cross-sectional geometry. After generation of the color 3D data set, flow velocity values from cross sections perpendicular to the tubes were analyzed to determine flow rate and stroke volume. Results: The flows from 3D digital velocity profiles showed close correlation with peak instantaneous flow rates (r = 0.99, y = 1.01x − 0.9, standard error of estimate 4.1 mL/s). When interpreted with pulsed wave Doppler data obtained through the cardiac cycle, they also allowed computation of stroke volume (r = 0.98, y = 1.44x − 2.5, standard error of estimate 3.8 mL). Conclusion: The ability to compute laminar flows from 3D digital data sets obtained parallel to the direction of flow and without the need for geometric assumptions represents an important opportunity for and advantage of 3D color Doppler echocardiography. (J Am Soc Echocardiogr 2000;13:841-8.)

Three-dimensional reconstructions of normal and aneurysmatic left ventricles in vivo using transesophageal echocardiography

Objective: To perform three-dimensional surface reconstructions to provide spatial delineations of a normal and an aneurysmatic left ventricle, using transesophageal echocardiography. Design: Prospective study. Setting: University hospital. Participants: Eight patients in cardiogenic shock admitted to the intensive care unit and two patients undergoing surgery with general anesthesia. Interventions: Using a multiplane transesophageal echocardiography probe, nine echocardiographic cross-sectional images of the heart at approximately 20° angular increments were obtained from midesophageal level in each patient for three-dimensional surface reconstructions. Multiple determinations of cardiac output using the thermodilution principle were also made in each patient to verify the accuracy of three-dimensional data sets. Measurements and Main Results: End-diastolic and end-systolic volumes were determined from three-dimensional data sets using the disc-summation method. Stroke volume was derived as the difference between end-diastolic and end-systolic volumes. Stroke volume was also calculated from thermodilution cardiac output measurements and heart rate. Correlation and limits of agreement between stroke volumes derived by the two methods were determined. Three-dimensional wire-frame models of a normal and an aneurysmatic left ventricle at end-systole were constructed from the nine echocardiographic cross-sectional images. Correlation coefficient between stroke volume derived from three-dimensional data sets using the disc-summation method and that measured by the thermodilution method was 0.91 ( p < 0.001). Wire-frame models reveal a normal symmetric cavity and an aneurysmal cavity in sharp relief. Conclusions: Three-dimensional surface reconstruction can be performed from multiple cross-sectional images obtained using an unmodified commercially available multiplane transesophageal echocardiography probe, to reveal the left ventricular cavity in sharp relief. High correlation between stroke volume calculated from three-dimensional data sets and that measured by the thermodilution method attests to the accuracy of the three-dimensional data sets.

Microbubbles associated with mechanical heart valves: Their relation with serum lactic dehydrogenase levels

Background There has been no consensus about the prevalence and mechanism of generation of microbubbles in mechanical prosthetic heart valves (PHV). The aim of this study was to determine the prevalence of microbubbles in PHV and their relation to serum lactic dehydrogenase (LDH) levels. Methods and Results We prospectively studied 150 normally functioning mitral PHV (98 bileaflet and 52 monoleaflet) in 150 patients with the use of transesophageal echocardiography with a multiplane 5-MHz probe. None of the patients had an aortic prosthetic valve. Blood was drawn to determine serum LDH level. None of the patients had any factors that might affect the LDH level other than the PHV-related hemolysis. Patients with spontaneous echo contrast in the left atrium that might affect the assessment of the microbubbles were excluded. We devised a method to determine the amount of microbubbles for each PHV. Microbubbles were detected in 118 (79%) of 150 PHV, including 97 (99%) of 98 bileaflet valves and 21 (40%) of 52 monoleaflet (tilting disk) valves ( P < .0001). Intraobserver variability was not statistically significant for the determination of the amount of microbubbles ( z = 1.7, P = .08). There was a strong correlation between serum LDH levels and the amount of microbubbles ( r s = 0.69, P < .001). Conclusions Microbubbles were detected in more patients than reported previously. They were found to be associated more with the bileaflet than the monoleaflet PHV. Sorin monoleaflet valves were associated with microbubbles significantly less often than the others. There was a strong correlation between serum LDH levels and microbubble counts, which suggests that hemolysis may be related to microbubble formation. (Am Heart J 1999;137:463-8.)

Intraoperative Transoesophageal Echocardiography as an Adjuvant to Fluoroscopy during Endovascular Thoracic Aortic Repair

Objectives:to define the utility of intraoperative transeophageal echocardiography (TEE) during endovascular thoracic aortic repair.Design:retrospective study.Materials:five patients underwent six transluminal endovascular stent-graft procedures for repair of thoracic aortic disease.Methods:after induction of anaesthesia, a multiplane or biplane TEE probe was placed to obtain views of the diseased aorta. Both transverse and longitudinal planes of the aortic arch and descending thoracic aortic segments were imaged. The aortic pathology was confirmed by TEE and the proximal and distal extents of the intrathoracic lesion were defined. Doppler and colour-flow imaging was used to identify flow patterns through the aorta before and after stent-graft deployment.Results:visualisation and confirmation of the aortic pathology by ultrasonography was accomplished in all patients. TEE was able to confirm proper placement of the endograft relative to the aortic lesion after deployment and was able to confirm exclusion of blood flow into the aneurysm sacs.Conclusions:TEE may facilitate repair by confirming aortic pathology, identifying endograft placement, assessment of the adequacy of aneurysm sack isolation, as well as dynamic intraoperative cardiac assessment.

Three-dimensional surface area of the aortic valve orifice by three-dimensional echocardiography: Clinical validation of a novel index for assessment of aortic stenosis

Background A direct and accurate method of assessing aortic valve area (AVA) in patients with aortic stenosis (AS) is desirable because of the well-known theoretical and practical limitations of the currently available methods. We assessed the clinical feasibility and accuracy of a novel index, the 3-dimensional surface area (3-DSA) of the aortic valve orifice by 3-dimensional transesophageal echocardiography (3-DTEE) in patients with AS. Methods Intraoperative 3-DTEE was performed in 23 consecutive patients (mean age 58 ± 15 years) with valvular AS using a Toshiba SSA-380A system with a multiplane TEE probe and a TomTec EchoScan system. The 3-DTEE acquisition, processing and reconstruction were conducted and the aortic valve orifice presented using a “surgeon’s aortotomy view” (aortic valve orifice as if viewed through an open aortic root). The 3-D images were videotaped and calibrated and the 3-DSA measured by planimetry of the inner surface of the aortic valve leaflets at the maximal systolic opening using the dynamic 3-D images. For comparison, the 2-D cross sectional area (2-DCSA) of the aortic valve was also determined by 2-DTEE. The 3-DSA and 2-DCSA were compared with the AVA by the invasive Gorlin formula and the Doppler continuity equation method by transthoracic echocardiography. Results The 3-DSA and 2-DCSA measurements were feasible in all but one patient. Both 3-DSA and 2-DCSA correlated moderately well with the AVA by the Gorlin formula (n = 17, r = 0.66, standard error of the estimate [SEE] = 0.3 cm 2 , P < .05 for 3-DSA and r = 0.61, SEE = 0.5 cm 2 P < .05 for 2-DCSA, respectively). They also correlated well with the AVA by Doppler continuity equation method (n = 22, r = 0.90, SEE = 0.1 cm 2 , P < .05 for 3-DSA and r = 0.83, SEE = 0.3 cm 2 , P < .05 for 2-DCSA, respectively). There was no statistically significant difference between the 3-DSA and AVA by both the Gorlin formula (Δ = 0.1 ± 0.3 cm 2 , P = .3) and the Doppler continuity equation (Δ = –0.0 ± 0.3 cm 2 , P = .7). In contrast, the 2-DCSA significantly overestimated AVA by the Gorlin formula (Δ = 0.5 ± 0.5 cm 2 , P < .005) and by the Doppler continuity equation (Δ = 0.5 ± 0.6 cm 2 , P < .0001). Conclusions Planimetry of 3-DSA of the aortic valve orifice by 3-DTEE is a clinically feasible and relatively accurate technique for assessment of AVA and is superior to 2-DCSA by 2-DTEE. (Am Heart J 1998;136:1042-50.)

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.

Intraoperative transesophageal echocardiography for pediatric patients with congenital heart disease.