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.     

Thoracic aortic dissection: diagnosis with transesophageal echocardiography versus MR imaging

PURPOSE: To compare transesophageal echocardiography (TEE) and magnetic resonance (MR) imaging in the diagnosis of dissection of the thoracic aorta. MATERIALS AND METHODS: Thirty-one consecutive patients with clinically suspected aortic dissection and 10 postoperative patients underwent transesophageal color Doppler echocardiography and MR imaging. Imaging results were compared at independent double-blind readings. Final diagnosis was obtained from consensual review of all corroborative studies. RESULTS: MR imaging depicted the intimal flap in 95% of aortic dissections; TEE, in 86% (P < .05). In surgical patients, the sensitivity of MR in detection of residual dissection was 100% versus 86% with TEE (P < .05). The inferior extent of the dissected lumen was seen only with MR imaging. False-positive results occurred in two cases with TEE and in one with MR imaging. CONCLUSION: MR imaging is superior to TEE in the evaluation and follow-up of dissection of the thoracic aorta. Because the availability of MR is limited, however, TEE should remain the standard modality for diagnosis.     

Transesophageal echocardiography in mitral prosthesis dysfunction: usefulness and limitations in the evaluation of mitral insufficiency

This study was performed to test the usefulness of transesophageal echocardiography in the diagnosis and assessment of pathological mitral regurgitation in patients with mitral valve prostheses. Doppler color flow imaging by transesophageal echocardiography was compared to the transthoracic echocardiography and angiographic and surgical assessment. We analyzed the influence of the spatial configuration of the jet on the semiquantitative assessment of mitral regurgitation. We studied 71 patients with prostheses in mitral position which were submitted for transesophageal echocardiography examination. 51 of these patients were found to have a pathological prosthetic regurgitation that was confirmed in 21 cases by left ventriculography and in 4 during cardiac surgery. Transesophageal echocardiography Doppler color flow imaging identified a regurgitant jet in 31 patients (60.7%). There was complete agreement with the quantitative assessment of regurgitation by angiography or surgery in 36% of the cases. All patients with prosthetic insufficiency observed by angiography or during cardiac surgery were confirmed by transesophageal echocardiography. Complete agreement in grade of severity by transthoracic echocardiography was found in 84% of cases. There was a difference in grade of severity of mitral regurgitation in only 4 patients. Regurgitant jets were classified by transesophageal echocardiography color Doppler in two groups: free jets and impinging wall jets. 21 cases presented a free jet and 31 excentrically directed impinging wall jet of mitral regurgitation. There was complete agreement with hemodynamic assessment of severity in all patients with regurgitant free jets (11/11). In presence of jet wall there was understimation of mitral regurgitation in 28.5% (4/13).(ABSTRACT TRUNCATED AT 250 WORDS)     

Left atrial leiomyosarcoma: double occurrence and double recurrence--report of one case

In October 1996 a 67-year-old man underwent transthoracic and transesophageal echocardiography (TEE) because of dyspnea on exertion and was found to have 2 left atrial cardiac masses. The 2 masses were surgically removed from the atrium and showed histopathologic and ultrastructural features of a leiomyosarcoma. Seven months later a double recurrence of left atrial masses was found with TEE; the patient refused surgery and decided instead to receive chemotherapy. In May 1998 he was in stable condition (New York Heart Association class III), but a further growth of the 2 left atrial masses was observed at TEE. We describe the echocardiographic features of the 2 cardiac masses and the clinical and prognostic implications.     

Adjustable tricuspid valve annuloplasty assisted by intraoperative transesophageal color Doppler echocardiography

Intraoperative transesophageal echocardiography (TEE) can play a major role in active guidance of cardiac surgery. This study describes a new application of TEE for assisting tricuspid suture annuloplasty. Twenty-five patients (aged 52 +/- 11 years) who underwent mitral valve replacement and tricuspid valve annuloplasty were studied intraoperatively by TEE. After cardiopulmonary bypass, the suture annuloplasty was adjusted on the beating heart until palpable regurgitation was eliminated. Further adjustment of the suture was performed under echocardiographic guidance until color Doppler flow imaging showed the most adequate correction of tricuspid regurgitation (TR). A significant decrease in the semiquantitative grade of TR, of regurgitant jet area and of the ratio jet area/right atrial area was obtained when the suture was adjusted under echocardiographic guidance. The peak inflow velocity and the gradient across the tricuspid valve did not show significant changes throughout the procedures. The results showed that the tricuspid suture annuloplasty guided by TEE enables a substantial reduction in residual TR without creating valve stenosis.     

Usefulness of transesophageal echocardiography in the treatment of critically ill patients

To evaluate the usefulness of transesophageal echocardiography (TEE) in the treatment of critically ill patients, 80 patients (51 male and 29 female; mean age, 53 years) undergoing both transthoracic echocardiography (TTE) and TEE were studied in a 2-year period. Of these, 48 patients were studied in the ICU, while the other 32 patients were directly referred from the emergency departments. Indications for the study included suspected aortic dissection (34 patients), hemodynamic instability (22 patients), suspected cardiac source of embolism (11 patients), evaluation of the severity of mitral regurgitation (7 patients), and suspected infective endocarditis (6 patients). The probe was passed successfully in 78 of 80 attempts (98 percent). No significant complications were recorded during the transesophageal echocardiographic study. Transesophageal echocardiography provided critical information that was not obtained by TTE in 39 of 78 studies (50 percent, p < 0.005). Cardiac surgery was prompted by TEE findings in 14 patients (18 percent) and these findings were all confirmed at operation. Transesophageal echocardiography was a safe, well-tolerated, and valuable diagnostic approach for the rapid detection of specific cardiac abnormalities in patients with critical illness; TEE should be considered in the treatment of critically ill patients especially when TTE provided inadequate information.     

US-guided core breast biopsy: use and cost-effectiveness

OBJECTIVES: We sought to determine, using serial echocardiography, the hydrodynamic mechanisms involved in the occurrence of hemolysis after mitral valve repair. BACKGROUND: Recently, fluid dynamic simulation models have identified distinct patterns of mitral regurgitant flow disturbances in patients with mitral prosthetic hemolysis that were associated with high shear stress and may therefore produce clinical hemolysis. Rapid acceleration, fragmentation, and collision jets were associated with high shear stress and hemolysis whereas slow deceleration and free jets were not. METHODS: We reviewed serial echocardiographic studies of 13 consecutive patients with hemolytic anemia after mitral valve repair who were referred for mitral reoperation between January 1985 and December 1996 (group 1). Thirteen patients undergoing reoperation for mitral regurgitation after mitral valve repair but without hemolysis served as controls (group 2). RESULTS: The mitral regurgitant jet was central in origin in 12 group 1 patients and 9 group 2 patients (Fisher exact test, p= 0.3). The other patients had para-ring regurgitation. Group 1 patients had collision (n=11), rapid acceleration (n=2) or fragmentation (n=1) jets whereas group 2 patients had slow deceleration (n=11) or free jets (n=2) (Fisher exact test, p < 0.0001). One patient with hemolysis had both collision and rapid acceleration jets. The "culprit" jet could be identified on the postbypass transesophageal echocardiography (TEE) study in only 1 patient at the time of initial mitral repair. Twelve group 1 patients underwent reoperation, with subsequent resolution of hemolysis in all patients. At reoperation, the initial repair was found to be intact in 8 (67%) patients. CONCLUSION: Distinct patterns of flow disturbance associated with high shear stress were identified by color Doppler imaging in patients with hemolysis after mitral valve repair. The majority (92%) of these color flow disturbances were not present during intraoperative postbypass TEE study after initial mitral repair and subsequently developed in the early postoperative period.     

Chimpanzee (Pan troglodytes) pointing: hand shapes, accuracy, and the role of eye gaze

We have validated a new semiautomated method for quantification of volumetric flow applied to multiplane transesophageal color Doppler mapping. This Doppler technique assumes only the incompressibility of the fluid and includes variations of flow area. By computing velocity vectors across a surface normal to the point of scanning, volumetric flow can be measured independently of the angle of incidence between the ultrasonic beam and the direction of blood flow. Mitral valvular flow rate was measured during surgery by transesophageal color Doppler echocardiography in 27 patients undergoing coronary artery bypass grafting at 45 sets of observations. The results were compared with those obtained by the thermodilution technique. The mean of the differences between the thermodilution technique and color Doppler echocardiography was 0.06 +/- 0.866 L/min for the mitral valvular flows (mean of differences [thermodilution-color Doppler] &/- 2 SDs of differences). Thus mitral valvular volumetric flow measured by this color Doppler method showed a close agreement to the thermodilution technique during surgery.     

Value of transesophageal echography in the detection of left intraventricular masses. Apropos of a case of apical thrombus

The authors report a case of left intraventricular thrombus investigated by two-dimensional transesophageal echocardiography (TEE). Three longitudinal views obtained by rotation, left lateral inclination and by advancing the probe, enabled the precise evaluation of a mass situated at the apex of the left ventricle, together with ventricular morphology and kinetics. Two-dimensional TEE is electively indicated for confirmation of the diagnosis of left intraventricular apical masses, in particular in hypoechogenic patients and to guide possible surgery. The two-plane probe provides a certain number of sections which remain relatively limited but this problem is resolved with the development of multidimensional probes.     

Cancrum oris: management, incidence, and implications of human immunodeficiency virus in Zambia

BACKGROUND: Limitations in the imaging views that can be obtained with transesophageal echocardiography (TEE) have hindered development of a widely adopted Doppler method for cardiac output (CO) monitoring. The authors evaluated a CO technique that combines steerable continuous-wave Doppler with the imaging capabilities of two-dimensional multiplane TEE. METHODS: From the transverse plane transgastric, short-axis view of the left ventricle, the imaging array was rotated to view the left ventricular outflow tract (LVOT) and ascending aorta. Steerable continuous-wave Doppler was subsequently used to measure aortic blood flow velocities. Aortic valve area was determined using a triangular orifice model. Matched thermodilution and Doppler CO measurements were obtained serially during surgery. RESULTS: The left ventricular outflow tract was imaged in 32 of 33 patients (97%). Data analysis reveal a mean difference between techniques of -0.01 l/min, and a standard deviation of the differences of 0.56 l/min. Multiple regression showed a correlation of r = 0.98 between intrasubject changes in CO. Multiplane TEE correctly tracked the direction of 37 of 38 serial changes in thermodilution CO but with a modest 14% underestimation of the magnitude of these changes. CONCLUSIONS: These results indicate that multiplane TEE can provide an alternative method for the intraoperative measurement of CO. The ability of the rotatable imaging array to align with the left ventricular outflow tract and the need for only minimal adjustments in probe position advance the utility of intraoperative TEE.     

Staphylococcus aureus cap5O and cap5P genes functionally complement mutations affecting enterobacterial common-antigen biosynthesis in Escherichia coli

BACKGROUND: Excision of large right atrial masses requires bicaval cannulation and cardiopulmonary bypass. Safe venous cannulation can be accomplished only by knowing the exact intracavitary location and extension of the mass to avoid fragmentation. Transthoracic echocardiography and intraoperative transesophageal echocardiography, although helpful, cannot always define the exact intracavitary relationships of the tumor. METHODS: We have used both intraoperative transesophageal and epicardial echocardiography to guide venous cannulation in 4 patients with large right atrial masses. Both echo images are used by the surgeon to select the exact site and method of cannulation to avoid fragmentation of the mass. Epicardial echocardiography complemented the images obtained by transesophageal echocardiography. RESULTS: The technique of combined transesophageal and epicardial echocardiography allowed safe venous cannulation in all 4 patients. Each of the right atrial masses was safely excised using case-specific cannulation techniques guided by the echocardiographic images. CONCLUSIONS: We propose the routine use of both intraoperative transesophageal and epicardial echocardiography in guiding venous cannulation for safe excision of large right atrial masses.     

Transnasal transesophageal echocardiography: a modified application mode for cardiac examination in ventilated patients

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.     

The comparative value of transesophageal and transthoracic echocardiography before and after percutaneous mitral balloon valvotomy: a prospective study

Transthoracic (TTE) and transesophageal echocardiography (TEE) were performed prospectively on 53 consecutive patients (mean age 59 +/- 14 years) immediately before and within 24 hours of mitral balloon valvotomy to compare the relative value of the two techniques. Biplane TEE was used in 38 patients and single-plane imaging was done in 11. All patients underwent left and right cardiac catheterization, left ventriculography, and coronary angiography. While TEE provided excellent images of the mitral valve in all patients, imaging planes were more limited than by TTE. Mitral valve morphology could be assessed satisfactorily by either technique. Echo scores derived from each showed good correlation (r = 0.90, p < 0.001). TEE transgastric longitudinal scanning provided superior detail of the subvalvar apparatus but only in 20 (53%) of 38 patients. Patients with good transgastric views had significantly smaller left atrial volumes than those without (58 +/- 22 vs 106 +/- 41 cm3, p < 0.001). Mitral valve orifice and the commissures were better assessed by TTE. Before valvotomy, mitral regurgitation (MR) graded by TEE and TTE color flow mapping was concordant with angiography in 80% and 81%, respectively. After valvotomy, TTE color flow mapping failed to detect MR in two of the three patients who developed severe MR. Two of these patients were examined by TEE, which demonstrated both the MR jets as well as leaflet tears. Thrombus was diagnosed in the left atrium in eight patients by TEE and in only one patient by TTE. Biplane TEE was required for accurate thrombus localization and for assessing its size and extent. Five patients with thrombus underwent balloon valvotomy without complications. Left-to-right atrial shunting was detected by TEE and TTE in 95% and 48% of patients, respectively. Flow convergence regions, from which quantitative flow information can be derived, were imaged by TEE only. TTE and TEE have complementary roles. However, TEE is essential for excluding thrombus in the left atrium before balloon valvotomy. After the procedure, TEE is recommended for the evaluation of patients with severe mitral regurgitation.     

Multiplane transesophageal echocardiographic doppler imaging accurately determines cardiac output measurements in critically ill patients

OBJECTIVES: To compare cardiac output and stroke volume measured by multiplane transesophageal Doppler echocardiography with that measured by the thermodilution technique. DESIGN: Prospective direct comparison of paired measurements by both techniques in each patient. SETTING: Cardiac surgery and myocardial infarction intensive care units. PATIENTS: Twenty-nine patients, mean age (+/- SD) 67 +/- 8 years. Nineteen had undergone open heart surgery and 10 had suffered acute myocardial infarction. METHODS: Cardiac output and stroke volume were measured simultaneously by the thermodilution technique and multiplane transesophageal Doppler echocardiography via the transgastric view (119 +/- 8 degrees) with the sample volume positioned at the level of the left ventricular outflow tract. RESULTS: Stroke volume and cardiac output measurements were obtained in 29 of 33 patients (88%). Mean values were 50 +/- 13 mL and 4.8 +/- 1.3 L/min by Doppler and 51 +/- 14 mL and 4.9 +/- 1.4 L/min by thermodilution (r = 0.90, r = 0.91, p < 0.001). The mean differences in values obtained with the two techniques were 1 +/- 6 mL (2 +/- 12%) and 0.1 +/- 0.7 L/min (2 +/- 12%). CONCLUSIONS: Multiplane transesophageal echocardiography enhances the ability to estimate accurately cardiac output and stroke volume by providing new access to left ventricular outflow tract in critically ill patients.     

A case of aortic dissection after the termination of cardiopulmonary bypass

We report, a case of aortic dissection after the termination of cardiopulmonary bypass (CPB), which was diagnosed by transesophageal echocardiography (TEE). A 70-year old male with aortic regurgitation received aortic valve replacement. After the termination of CPB, the aortic dissection was diagnosed by TEE. Furthermore wall motion abnormality was found by TEE, and aorto-coronary bypass was performed after observation by TEE. This case report suggests that TEE is useful not only for diagnosis but also for therapeutic orientation of aortic dissection.     

Femoral injection of echo contrast medium may increase the sensitivity of testing for a patent foramen ovale

OBJECTIVE: The diagnosis of a patent foramen ovale (PFO) as a cause of stroke is of increasing interest especially in young (<45 years) patients. METHODS: We studied potential right-to-left shunting using transesophageal echocardiography (TEE) and bilateral transcranial Doppler sonography (TCD) of the middle cerebral artery (MCA) simultaneously in 44 patients. All patients were younger than age 45 years and suffered from an acute ischemic stroke or transient ischemic attack. Other possible etiologies were excluded. Echo contrast medium was injected in an alternating mode via antecubital or femoral veins. Tests were performed with and without the Valsalva maneuver. The criteria for a PFO were that the contrast pass from the right to the left atrium (TEE) and early detection (<10 seconds) of more than 10 micro air bubbles in at least one MCA by TCD. RESULTS: A PFO was diagnosed in 22 patients (50%). The detection rate with TEE/TCD was 11.4%/4.5% via antecubital injection, 18%/13.6% via antecubital injection plus the Valsalva maneuver, 38.6%/36% via femoral injection alone, and 50%/50% via femoral injection plus the Valsalva maneuver. The difference between femoral and antecubital injections was significant with and without the Valsalva maneuver (p < 0.01, chi2 test). There were no differences between TEE and TCD after femoral injection with the Valsalva maneuver. The brain transit time was 4.6 +/- 2.1 seconds for femoral injection and 6.3 +/- 4.1 seconds for antecubital injection. CONCLUSIONS: The sensitivity in detecting a PFO was markedly increased by femoral injection. This may be caused by different inflow patterns to the right atrium: inferior vena caval flow is directed to the right atrial septum, whereas superior vena caval flow is directed to the tricuspid valve. Thus, femoral injection may help to improve the detection of PFO and may explain the differences between TEE and TCD findings in previous studies.     

Simultaneous measurement of pulmonary venous flow by intravascular catheter Doppler velocimetry and transesophageal Doppler echocardiography: relation to left atrial pressure and left atrial and left ventricular function

OBJECTIVES: The aim of our study was to compare measurements of pulmonary venous flow velocity obtained either by transesophageal Doppler echocardiography or by intravascular catheter Doppler velocimetry. Furthermore, the relation among pulmonary venous flow velocity, left atrial compliance and left atrial pressure was evaluated. BACKGROUND: Data about the relation between left atrial pressure and pulmonary venous flow velocity are controversial. METHODS: A total of 32 patients undergoing elective open heart surgery for coronary artery bypass grafting were included prospectively in the study. Pulmonary venous flow velocity (Doppler catheter) and left atrial pressure (microtip pressure transducer) were recorded simultaneously with recordings of pulmonary venous flow velocity obtained by transesophageal Doppler echocardiography. RESULTS: Agreement between Doppler catheter and Doppler echocardiographic measurements of pulmonary venous flow velocity (n = 18 patients) was analyzed using the Bland-Altmann technique. The 95% limits of agreement were -0.16 to +0.11 m/s for systolic peak velocity, -0.14 to +0.09 m/s for diastolic peak velocity and -0.12 to +0.10 m/s for atrial peak velocity. The closest agreement between both methods was found for the ratio of systolic to diastolic peak velocity, the ratio of systolic to diastolic flow duration and the time from Q deflection on the electrocardiogram to maximal flow velocity. Mean left atrial pressure was strongly correlated with the ratio of systolic to diastolic peak velocity (r = -0.829), systolic velocity-time integral (r = -0.653), time to maximal flow velocity (r = 0.844) and the ratio of systolic to diastolic flow duration (r = -0.556). The ratio of systolic to diastolic peak velocity and the time to maximal flow velocity were identified as strong independent predictors of mean left atrial pressure. Left atrial compliance was not found to be an independent predictor of mean left atrial pressure. CONCLUSIONS: Flow velocity in the left upper pulmonary vein can be reliably recorded by transesophageal pulsed wave Doppler echocardiography. Our data reveal further evidence that mean left atrial pressure can be estimated by the pattern of pulmonary venous flow velocity.     

Frequency of deep vein thrombosis in patients with patent foramen ovale and ischemic stroke or transient ischemic attack

To evaluate the additional value of transesophageal (TEE) compared with transthoracic (TTE) echocardiography and the role of patent foramen ovale (PFO) and deep vein thrombosis in the work-up of embolic events, patients with presumed cardiac embolic stroke or transient ischemic attack (neurovascular etiology was excluded) were prospectively studied by transthoracic and transesophageal contrast echocardiography. If PFO was detected echocardiographically, PFO size was assessed semiquantitatively and phlebography of both legs was performed. Two hundred forty-two consecutive patients (153 men, 60 +/- 15 years) were studied. In 197 patients, neuroimaging showed evidence of embolic infarction. TEE identified 138 potential cardiac sources of embolism in 111 patients, compared with 69 by TTE (p <0.01) in 59 patients. TEE detected potential cardiac sources in 52 patients with negative TTE examination and was significantly superior compared with TTE for identifying left atrial thrombi, spontaneous echo contrast, PFO, atrial septal aneurysm, and atheroma of the ascending aorta. In patients with a positive TTE, additional diagnostic information by TEE was found in only 6 patients and did not change therapy. Phlebography was performed in 53 patients with PFO and revealed deep vein thrombosis in 5 patients (9.5%); all had medium or large PFOs. Thus, in patients with cerebral ischemia of suspected cardiogenic origin and a normal TTE examination, TEE detects potential causes of embolism in 31% of patients and is therefore of diagnostic relevance. Conversely, in the presence of a diagnostic TTE an additional TEE confers only marginal diagnostic benefit. Deep venous thrombosis was detected in nearly 10% of patients with PFO as the sole identifiable cardiac risk factor. Given that in 4 of 5 patients deep vein thrombosis was clinically silent, phlebography should be performed in patients with medium or large interatrial shunts if paradoxical embolism is suspected.     

Gradient echo MRI for measurement of the pulmonary autograft diameter after transplantation to the aortic root: validation and comparison with ultrasound

The purpose of this study was to s the value of MRI for measurement of pulmonary autograft diameters after transplantation to the aortic root in adults. Thirty-eight adults underwent this operation. MRI and transesophageal echocardiography (TEE) were performed in 30 and 27 patients, respectively, after a mean follow-up period of 2.8 years. For internal validation of MRI, measurements at the diastolic short and long axes of the sinus level were used. Pulmonary autograft diameters were measured and compared with MRI and TEE at five different levels: the subannular region (1), annulus (2), sinus (3), sinotubular junction (4), and the distal part of the autograft (5). The correlation coefficient (r2) between long- and short-axis measurements for corresponding sinuses was .97. Diameters obtained with MRI were 1 to 3 mm larger than those obtained with TEE (P < .05), except for the annulus at systole (P > .3). Cine gradient echo MRI is an appropriate technique to evaluate pulmonary autograft diameters during follow-up. Concordance with TEE was good, apart from a systematic difference of approximately 2 mm.     

Value and limitations of transesophageal echocardiography in infective endocarditis

Echocardiography has contributed considerably to the evolution in the management of patients with infective endocarditis. There is a clear hierarchy with respect to sensitivity of the different methods is superior when compared to 2-D and M-mode echocardiography in identifying both vegetations and perivalvular complications e.g. abscess formation, aneurysms, mural endocardial lesions. For patients with suspected endocarditis, in whom vegetations can not be clearly identified or in whom abscess formation is suspected with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) with mono- or multiplane scans has become the standard diagnostic procedure. For the examination of prosthetic valves it is the method of choice. It has even been suggested that it is employed as routine measure in all patients with suspected infective endocarditis. TEE is a safe semi-invasive technique with an extremely low complication rate and high sensitivity. Its specificity depends largely on the patient group which is examined. In patients with indicative clinical symptoms the specificity and the predictive value of vegetations are high. When used as screening method to assess echodense formations at cardiac valves particularly in the elderly, in whom degenerative changes prevail, its specificity and positive predictive value of vegetation-like structures are much lower. The negative predictive value of a negative transesophageal echocardiogram remains high, however. Valve abscesses are detected rarely by transthoracic echocardiography. It is the domain of TEE to assess them particularly in the aortic and mitral valve area. For them the specificity and positive predictive value of TEE in the diagnosis of infective endocarditis is high again. Of further importance was the observation that patients with vegetations of > 10 mm were more likely to suffer embolic complications. It should be noted, however, that infective endocarditis remains a clinical diagnosis: neither is the demonstration of a vegetation already the equivalent of endocarditis, nor does missing vegetations completely rule out the possibility of it. But without doubt, the presence of vegetations, of abscess formation or a concomitant pericardial effusion add valuable information to clinical diagnosis of infective endocarditis, which still needs a "high index of suspicion".