Transesophageal Echocardiography for Prosthetic Valve Evaluation:

Transesophageal echocardiography provides excellent images of mitral and aortic prostheses, due to its higher resolution and less interference from other cardiac structures. Since the introduction of transesophageal echocardiography, it has proved to be valuable for the evaluation of prosthetic heart valves. "Classic" indications include the evaluation of prosthetic valve endocarditis, the search for paravalvular abscesses, and the assessment of regurgitation in mechanical, especially mitral, prostheses. New technical developments such as biplane or multiplane transducers enhance the diagnostic capabilities of the technique. Transesophageal echocardiography can also have advantages in recognizing obstructive lesions such as thrombi or pannus, and help understand the complex morphology of prostheses in grafts. Transesophageal echocardiography should be considered a backup technique whenever transthoracic echocardiography, which always remains the primary approach, is inconclusive or negative in the presence of clinically suspected prosthetic valve malfunction.     

经胸与经食管超声心动图对心脏人工瓣膜的对比研究

４７例心脏人工机械瓣膜置换术后的病人，经胸超声心动图（ＴＴＥ）和经食管超声心动图（ＴＥＥ）对比研究显示，低估二尖瓣置换后人工瓣膜返流程度的分级和返流的发生率；主动脉瓣和二尖瓣置换的病人，ＴＴＥ探查人工二尖瓣返流的效果硬差。ＴＥＥ能较容易地探查人工二尖瓣瓣周漏。揭示对人工二尖瓣的评价，ＴＥＥ比ＴＴＥ能提供更多更可靠的信息，毫无疑问这是由于ＴＴＥ检查时人工瓣膜材料的声衰减和血流掩盖的影响，但我们的经验揭示，在评价主动脉瓣置换人工瓣膜时，ＴＥＥ并不优于ＴＴＥ。     

Transesophageal color Doppler flow imaging in the evaluation of prosthetic cardiac valves

To determine the value of transesophageal echocardiography in the assessment of prosthetic cardiac valves, 11 patients with clinically suspected cardiac prosthetic valve dysfunction were studied by transesophageal two-dimensional imaging, as well as by color Doppler flow mapping. Among these 11 patients, there were 10 with biological tissue valves and 3 with metallic valves (1 Bjork-Shiley, 2 St. Jude). Nine patients had replacement of mitral valves alone. The remaining two had received both mitral and aortic prostheses. The degree of mitral regurgitation was graded by transesophageal color Doppler according to the area of the regurgitant jet visualized. The degree of aortic regurgitation was graded by the jet height/left ventricular outflow height ratio method. All transesophageal studies were performed without complication and all were well tolerated. The pathological morphology of the cardiac prosthesis was clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery. Of those tested, one patient was found to have a torn leaflet, one had a dislodged leaflet, one patient had paravalvular leakage, four had cusp vegetations, and five patients had prosthetic degeneration for other reasons. Mitral regurgitation was graded as absent in one patient, mild in two patients, moderate in two patients, and severe in six patients. Aortic regurgitation was graded as severe in both patients with aortic prostheses. We conclude that in patients with clinically suspected cardiac prosthetic dysfunction, transesophageal two-dimensional imaging combined with color Doppler can provide reliable information that corresponds to surgical findings.     

Comparison of transthoracic and transesophageal assessment of prosthetic valve dysfunction

Transesophageal echocardiography has added another dimension to the assessment of prosthetic valve dysfunction with high-resolution images that allow for more detailed structural evaluation of tissue and mechanical valves. This study is a retrospective analysis of 140 prosthetic valves (90 tissue, 50 mechanical) in the mitral (89), aortic (45), and tricuspid (6) position in 116 patients studied by transthoracic and transesophageal echocardiography techniques. Transesophageal echocardiography was consistently better than the transthoracic technique in the evaluation of structural abnormalities of tissue valves in the mitral and aortic positions with respect to leaflet thickening, prolapse, flail, and vegetations. With transesophageal echocardiography, five tissue mitral valves had flail leaflets that were not identified by the transthoracic technique. Transesophageal echocardiography was better than transthoracic in the detection, quantification, and localization of prosthetic mitral regurgitation. Physiological mitral regurgitation was detected in 31 valves by transesophageal echocardiography compared to seven by transthoracic technique. By transesophageal echocardiography, mitral regurgitation was paravalvular in 24% compared with 4% by transthoracic technique. Left atrial spontaneous contrast was seen in 42% of the patients with a mitral prosthesis detected only by transesophageal echocardiography. Six patients had left atrial or left atrial appendage thrombus and in five patients they were detected only by transesophageal echocardiography. We conclude that transesophageal echocardiography should be a complimentary test to transthoracic studies in patients with suspected prosthetic valve dysfunction or for the follow-up of older tissue valves.     

Single-plane transesophageal echocardiography for assessing function of mechanical or bioprosthetic valves in the aortic valve position.

To assess the value and limitations of single-plane transesophageal echocardiography in the evaluation of prosthetic aortic valve function, 89 patients (69 mechanical and 20 bioprosthetic aortic valves) were studied by combined transthoracic and transesophageal 2-dimensional and color flow Doppler echocardiography. In the assessment of aortic regurgitation, the transthoracic and transesophageal echocardiographic findings were concordant in 71 of 89 patients (80%). In 8 patients, the degree of aortic regurgitation was underestimated by the transthoracic approach; in each case the quality of the transthoracic echocardiogram was poor. In 10 patients, transesophageal echocardiography failed to detect trivial aortic regurgitation due to acoustic shadowing of the left ventricular outflow tract from a mechanical valve in the mitral valve position. Transesophageal echocardiography was superior to transthoracic echocardiography in diagnosing perivalvular abscess, subaortic perforation, valvular dehiscence, torn or thickened bioprosthetic aortic valve cusps, and in clearly distinguishing perivalvular from valvular aortic regurgitation. Transesophageal echocardiography correctly diagnosed bioprosthetic valve obstruction in 1 patient, but failed to diagnose mechanical valve obstruction in another. In conclusion, transesophageal echocardiography offers no advantage over the transthoracic approach in the detection and quantification of prosthetic aortic regurgitation unless the transthoracic image quality is poor. Transesophageal echocardiography is limited in detecting mechanical valve obstruction and in detecting aortic regurgitation in the presence of a mechanical prosthesis in the mitral valve position. However, it is superior to transthoracic echocardiography in identifying perivalvular pathology, differentiating perivalvular from valvular regurgitation and in defining the anatomic abnormality responsible for the prosthetic valve dysfunction. Combined transthoracic and transesophageal examination provides complete anatomic and hemodynamic assessment of prosthetic aortic valve function.     

Regurgitation jets in mitral prosthesis studied using transesophageal echocardiography

STUDY OBJECTIVE: To analyze the regurgitant jets of mitral valve prostheses studied by transesophageal echocardiography. DESIGN: Prospective study of patients with mitral prostheses with or without suspicion of dysfunction. SETTING: Patients referred to the Echocardiology Department of the Instituto de Cardiologia in Madrid, some as outpatients. PATIENTS AND INTERVENTIONS: Twenty five patients with mitral valve prostheses (5 biological, 7 St Jude, 12 Bjork Shiley and 1 Hall Kaster). Ten male patients and fifteen female, mean age 50 years. Five also had aortic valve prostheses. In only 5 there was a suspicion of dysfunction. The transthoracic echos were done with phased array transducers and the transthoracic with 2.5 (18 patients) or 5 MHz (7 patients) transducers coupled to a commercial echocardiographer. The presence of regurgitant jets was looked for, as well as their origin, maximal area and length, their type and degree of turbulence. MAIN RESULTS: Only 3 mitral regurgitations were noticed by transthoracic echocardiography. All the mechanical prostheses and 80% of the biological ones had regurgitant jets by transesophageal echocardiography. The tilting disc prostheses had two physiological jets, the St. Jude 2, 3, or exceptionally only one central jet. The biological prostheses had one central regurgitant jet, that was smaller than those from the mechanical prostheses (p less than 0.05). There were ten malfunctioning prostheses (5 Bjork Shiley, 3 St Jude and 2 biological). The diagnosis of dysfunction was based on the abnormal origin of the jet (9 cases) or just simply on the characteristics of the regurgitation (turbulence). Four patients were submitted to surgery, all with dysfunctioning prostheses. CONCLUSIONS: Transthoracic echocardiography has a low sensitivity for detecting the regurgitant jets of mitral prostheses. All mechanical prostheses and 80% of biological ones have regurgitation by transesophageal echocardiography. The area and length of the jets are not so different between normal and malfunctioning prostheses in order to separate them. The abnormal jets are recognised because of their abnormal origin and/or their characteristics, with formation of mosaic in color coded Doppler echocardiography.     

Additional diagnostic value of multiplane echocardiography over biplane imaging in assessment of mitral prosthetic valves.

OBJECTIVE: To evaluate how often multiplane transoesophageal echocardiography yields new or complementary data in mitral prostheses in comparison with the exclusive use of biplane imaging. PATIENTS: 73 consecutive patients with mitral prostheses who underwent multiplane transoesophageal echocardiograpy between January 1993 and December 1994. METHODS: Biplane images (transverse and longitudinal planes) and multiplane images (transverse, longitudinal, and intermediate planes) were recorded on two separate videotapes. The data provided by multiplane transoesophageal echocardiography were evaluated as (a) new data (abnormalities missed by biplane imaging); (b) complementary data (better delineating lesions already visualised by biplane imaging); or (c) redundant data (data already provided by biplane imaging). RESULTS: Multiplane transoesophageal echocardiography revealed new abnormalities in seven patients (9.5%) (thrombi in three and paraprosthetic leaks in the remaining four) and complementary data in nine (12.3%). In patients with paraprosthetic regurgitation, the possibility of continuously visualising the sewing ring by means of sequential angulations allowed the circumferential extension of the leak to be measured. In seven patients with paravalvar regurgitation who underwent surgery, the extension of the leak as measured by the multiplane approach closely corresponded with the surgical data. CONCLUSIONS: In comparison with the exclusive use of biplane imaging, the multiplane approach added new or complementary data in a significant proportion of patients with mitral prostheses. The ability to obtain the sequential adjacent planes allowed a more reliable appraisal of the extension of the leak and other abnormalities.     

Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma

Objectives. The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma.Background. Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined.Methods. We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data.Results. Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematom (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%.Conclusions. Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology, Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.     

Doppler echocardiography assessment of prosthetic heart valves

Transthoracic Doppler echocardiography is an accurate noninvasive method for the evaluation of prosthetic valve function. The flow characteristics and pressure gradients of normally functioning mechanical and bioprosthetic valves have been, in general established. Normal functioning mitral valve prostheses have a valve area > 1.8 cm² with the St. Jude valve having the largest effective valve area and normally functioning aortic prosthetic valves have a peak instantaneous gradient of < 45 mmHg, with the Starr-Edwards valves (Starr-Edwards, Irvine CA) showing the highest gradients. The incidence of minimal or mild regurgitation is approximately 15% to 30% in the mitral position and 25% to 50% in the aortic position, with the higher incidence of regurgitation seen with mechanical compared to bioprosthetic valves. Transthoracic Doppler echocardiography can accurately detect patients with prosthetic valvular stenosis. The presence of prosthetic aortic regurgitation can also generally be accurately assessed, except in the presence of both prosthetic aortic and mitral valves. Assessment of prosthetic mitral regurgitation remains limited due to significant attenuation of the ultrasound beam by the prosthesis and the frequent underestimation of severity of regurgitation. Other limitations of transthoracic studies include assessment of leaflet morphology, detection of vegetations and valve abscesses, and differentiation between valvular and paravalvular regurgitation.     

Assessment of mitral regurgitation by biplane transesophageal color Doppler flow mapping

To test the role of recently developed biplane transesophageal color Doppler echocardiography in the assessment of severity of mitral regurgitation, we examined 51 patients undergoing cardiac catheterization and left ventriculography. Transesophageal color Doppler flow imaging detected mitral regurgitation in all 32 patients proved to have this lesion. In 10 of 16 patients without mitral regurgitation by angiography, mitral regurgitation signals were detected by transesophageal color Doppler flow imaging. Thus, the sensitivity and specificity of transesophageal color Doppler echocardiography for the detection of mitral regurgitation were 100% and 38%, respectively. There was some correlation between the regurgitant jet area from the longitudinal plane and angiographic grading. An improved angiographic correlation was achieved with the regurgitant jet area from the transverse plane. The best correlation with angiography was obtained when the maximum regurgitant jet area from two planes (the greater of the two measurements, each from a different plane) was considered. There was a significant difference in the maximum regurgitant jet area between none and mild (p less than 0.01), mild and moderate (p less than 0.001), and moderate and severe (p less than 0.01) mitral regurgitation. The maximum regurgitant jet area of less than 1.5 cm2 predicted the angiographic grading as none with a sensitivity and specificity of 88% and 94%, respectively. The maximum regurgitant jet of between 1.5 and 4 cm2 predicted the angiographic grading as mild with a sensitivity and specificity of 82% and 95%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Doppler color flow mapping in the evaluation of prosthetic mitral and aortic valve function

Doppler color flow mapping and color-guided conventional Doppler studies were performed on 119 patients with 126 prosthetic valves (mitral alone in 60, aortic alone in 52 and both mitral and aortic in 7 patients) within 2 weeks of the catheterization study or surgery, or both. The mean pressure gradients derived by color-guided continuous wave Doppler ultrasound correlated well with those obtained at catheterization for both the tissue and mechanical mitral and aortic prostheses (r = 0.85 to 0.87). For the effective prosthetic orifice areas, better correlation with catheterization results were obtained with the tissue mitral (r = 0.94) and tissue aortic (r = 0.87) prostheses than with the mechanical mitral (r = 0.79) and mechanical aortic (r = 0.76) prostheses. The maximal width of the color flow signals at their origin from the tissue mitral prostheses also correlated well with the effective prosthetic orifice area at catheterization (r = 0.81). Doppler color flow mapping identified prosthetic valvular regurgitation with a sensitivity and specificity of 89% and 100%, respectively, for the mitral and 92% and 83% for the aortic prostheses. There was complete agreement between the Doppler color flow mapping and angiographic grading of the severity of prosthetic valvular regurgitation in 90% of mitral and 73.5% of the aortic regurgitant prostheses with under- or overestimation by greater than 1 grade in only two cases. Valvular and paravalvular regurgitation was correctly categorized by Doppler color flow mapping in relation to the surgical findings in 94% of the mitral and 80.5% of the aortic prostheses.     

Evaluation of mitral regurgitation by Doppler echocardiography

The diagnosis and assessment of mitral regurgitation has been one of the main challenges for cardiac ultrasound. Imaging techniques (M-mode and two-dimensional echocardiography) provide direct morphologic and etiologic information of the evaluation of patients with suspected mitral regurgitation. The advent of cardiac Doppler increased tremendously the ability to evaluate mitral regurgitation noninvasively. Continuous-wave and pulsed Doppler have been found to be sensitive and specific in the detection of mitral regurgitation. The introduction of color flow Doppler simplified enormously the assessment of patients with suspected mitral regurgitation. The maximal regurgitant area and maximal regurgitant area corrected for left atrial size have become the most commonly used parameters to evaluate mitral regurgitation by color flow Doppler in the clinical setting. However, the color regurgitant jet area is highly dependent on anatomical, hemodynamic, and equipment factors. A new method, based on the proximal isovelocity surface area, is being evaluated and appears to be relatively independent of equipment factors. Transesophageal echocardiography has been shown to be exquisitely sensitive in the detection of mitral regurgitation. Quantitation of mitral regurgitation by transesophageal echocardiography is currently based on the maximal regurgitant area and this parameter appears to correlate closely with the angiographic degree of mitral regurgitation. Pulmonary venous flow analysis had been used in conjunction with color flow mapping for the evaluation of mitral regurgitation by transesophageal echocardiography. The presence of reversed systolic flow has been shown to be sensitive and specific for the diagnosis of severe mitral regurgitation. Patients with clinically difficult surface studies, flail mitral valve leaflets, and prosthetic mitral valve are best evaluated by the transesophageal approach with interrogation of pulmonary venous flow.     

Regurgitant flow in cardiac valve prostheses: diagnostic value of gradient echo nuclear magnetic resonance imaging in reference to transesophageal two-dimensional color Doppler echocardiography.

Gradient echo nuclear magnetic resonance (NMR) imaging and transesophageal two-dimensional color Doppler echocardiography are flow-sensitive techniques that have been used in the diagnosis and grading of valvular regurgitation. To define the diagnostic value of gradient echo NMR imaging in the detection of regurgitant flow in cardiac valve prostheses and the differentiation of physiologic leakage flow from pathologic transvalvular or paravalvular leakage flow, 47 patients with 55 valve prostheses were examined. Color Doppler transesophageal echocardiography was used for comparison. Surgical confirmation of findings was obtained in 11 patients with 13 valve prostheses. Gradient echo NMR imaging showed regurgitant flow in 37 of 43 valves with a jet seen on transesophageal echocardiography and it detected physiologic leakage flow in 4 additional valves. There was 96% agreement between the two methods in distinguishing between physiologic and pathologic leakage flow. The methods differed on jet origin of pathologic leakage flow in six prostheses. The degree of regurgitation was graded by both NMR imaging and transesophageal echocardiography, according to the area of the regurgitant jet visualized; gradings were identical for 75% of valve prostheses. Quantification of jet length and area showed a good correlation between the two methods (r = 0.85 and r = 0.91, respectively). Gradient echo NMR imaging is a useful noninvasive technique for the detection, localization and estimation of regurgitant flow in cardiac valve prostheses. However, because transesophageal echocardiography is less time-consuming and less expensive, gradient echo NMR imaging is unlikely to displace transesophageal echocardiography and should be used only in the occasional patient who cannot be adequately imaged by echocardiography.     

Comparison of quantitative and semiquantitative methods for assessing mitral regurgitation by transesophageal echocardiography

Semiquantitative grading of mitral regurgitation (MR) by transesophageal echocardiography (TEE) is widely used for clinical decision making. However, the relation between semiquantitative grading by biplane or multiplane TEE and quantitative measures remains undetermined. Biplane or multiplane TEE was performed in 113 patients in the operating room. MR severity was graded from 1 to 4+ by Doppler color flow mapping. MR was quantified using the thermodilution-Doppler method as mitral regurgitant stroke volume (RSV) derived from the difference between total mitral inflow measured by pulsed Doppler and forward flow measured by thermodilution. Mitral regurgitant orifice area (ROA) was calculated by RSV divided by mitral regurgitant velocity. RSV and ROA were also calculated using the proximal isovelocity surface area method. RSV and ROA significantly correlated with the semiquantitative grading either by TEE or angiogram in a nonlinear fashion, with the best fit being given by an exponential model with correlation coefficients from 0.73 to 0.87 (p <0.001). Substantially increased RSV and ROA were observed in MR grades of > or =3+. In the same grades of 3+ or 4+ MR, the largest RSV was 4 times larger than the smallest (190 to 220 vs 44 to 45 ml), and the largest ROA (1.82 to 2.0 vs 0.26 to 0.27 cm2) was sixfold larger than the smallest. Patients with 2 to 3+ MR had significantly variable RSV and ROA (range 21 to 91 ml and 0.12 to 0.65 cm2, respectively). Color flow mapping by biplane or multiplane TEE or angiography is able to categorize precisely mild (< or =2+) and severe (> or =3+) MR, but cannot accurately determine actual hemodynamic load of MR in more severe degrees of MR.     

Assessment of severity of mitral regurgitation by measuring regurgitant jet width at its origin with transesophageal Doppler color flow imaging.

BACKGROUND. The ability of transesophageal color Doppler echocardiography to provide high-resolution images of both cardiac structure and blood flow in real time is advantageous for many clinical purposes. This study was performed to determine the utility of the regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging in the assessment of severity of mitral regurgitation. METHODS AND RESULTS. Sixty-three consecutive patients with mitral regurgitation underwent transesophageal color Doppler examination, and the diameter of regurgitant jet at its origin was measured. Both right and left cardiac catheterizations were performed within 24 hours of Doppler studies, and angiographic grading of mitral regurgitation and regurgitant stroke volume were evaluated. There was a close relation between the jet diameter at its origin measured by transesophageal Doppler color flow imaging and the angiographic grade of mitral regurgitation (r = 0.86, p less than 0.001). A jet diameter of 5.5 mm or more identified severe mitral regurgitation (grade III or IV) with a sensitivity of 92%, specificity of 92%, and positive and negative predictive values of 88% and 95%, respectively. In 31 patients with isolated mitral regurgitation, the jet diameter correlated well with the regurgitant stroke volume determined by a combined hemodynamic-angiographic method (r = 0.85, p less than 0.001). A jet diameter of 5.5 mm or more identified a regurgitant stroke volume of 60 ml or more with a sensitivity of 88%, specificity of 93%, and positive and negative predictive values of 94% and 87%, respectively. CONCLUSIONS. The regurgitant jet width at its origin measured by transesophageal Doppler color flow imaging provides a simple and useful method of measuring the severity of mitral regurgitation, and it may allow differentiation between mild and severe mitral regurgitation.     

Sensitivity and specificity of transesophageal echocardiography for determination of aortic valve morphology

BACKGROUND: Preoperative recognition of the presence of bicuspid aortic valve can be important in the planning of procedures. Multiplane transesophageal echocardiography may allow more accurate detection of valvular morphology than does biplane transesophageal echocardiography. METHODS AND RESULTS: The studies of 710 patients who subsequently underwent valvular or aortic surgery were reviewed in a blinded fashion. The inclusion criteria were adequate short-axis view and operative note confirmation of aortic valve morphology. Six hundred eight patients were submitted to further analysis. Four hundred three patients had aortic stenosis as the primary diagnosis. Three hundred sixty patients had biplane examinations and 248 had multiplane examinations. The sensitivity and specificity of the multiplane technique in assessing aortic valve morphology (bicuspid vs tricuspid valve) was 87% and 91%, respectively. The sensitivity and specificity of the biplane technique was 66% and 56%, respectively. Whether valves were calcified or not did not result in major changes in sensitivity and specificity for either technique. CONCLUSIONS: Multiplane transesophageal echocardiography provides a more accurate assessment of preoperative aortic valve morphology than does the biplane approach in the majority of patients.     

Regurgitant jet size by transesophageal compared with transthoracic Doppler color flow imaging

Combined echocardiography and Doppler color flow mapping from transthoracic imaging windows has become the standard method for the noninvasive assessment of valvular regurgitation. This study compared regurgitant jet areas by Doppler color flow imaging derived from the newer transesophageal approach with measurements obtained from conventional transthoracic apical views. Maximal regurgitant jet area determinations and an overall visual estimate of lesion severity were obtained from 42 patients who underwent color flow examination by both techniques. Seventy-three regurgitant lesions were visualized by transesophageal flow imaging: 34 mitral, 22 aortic, and 17 tricuspid jets. Transthoracic studies in the same patients revealed fewer regurgitant lesions for each valve; 20 mitral, 16 aortic, and 12 tricuspid (p = 0.0009). A comparison of maximal jet areas determined by transesophageal and transthoracic studies showed a good overall correlation (r = 0.85, SEE = 2.8 cm2) and a systematic overestimation by the transesophageal technique (TEE = 0.96 TTX + 2.7). For the subgroup with mitral insufficiency, valve lesions visualized by both techniques were larger by the transesophageal approach (n = 18, 6.0 versus 3.6 cm2, p = 0.008). Semiquantitative visual grading of individual valve lesions by two independent observers revealed a higher grade of regurgitation with more jets classified as mild (38 versus 25), moderate (18 versus 13), and severe (17 versus 10) by esophageal imaging than by transthoracic imaging. Thus, transesophageal color flow mapping techniques yield a higher prevalence of valvular regurgitation than do transthoracic techniques in the same patients. Jet area and the overall estimate of regurgitant lesion severity were also greater by transesophageal color Doppler imaging compared with standard transthoracic imaging.(ABSTRACT TRUNCATED AT 250 WORDS)     

Assessment of normal and abnormal prosthetic mitral valves by Doppler echocardiography Doppler in prosthetic mitral valves

Pulsed, continuous-wave, and color Doppler were performed in 165 normal mitral prostheses and 58 patients with prosthetic dysfunction (46 regurgitant and 12 obstructive valves) proved by catheterization and/or surgery. Mean mitral gradient (MG) and pressure half-time (PHT) were determined in all cases.Among normal prostheses, a wide range of both MG and PHT was observed in each type of valve and a considerable overlap between valves of different size. St-Jude's valve had the most optimal hemodynamics. Mild mitral insufficiency was detected in 14% of tissue and 24% of mechanical mitral valves.Repeat studies were performed in 30 patients over a 2.4 years period. Nine patients developed Doppler evidence of new prosthetic dysfunction, while Doppler parameters remained unchanged in 21 patients during the follow-up period.Among malfunctioning valves, Doppler correctly identified all cases of prosthetic obstruction (n=12), and 42 of 46 regurgitant valves.We conclude that Doppler echocardiography is a very useful technique in both non-invasive assessment and follow-up of normal prosthetic valves in the mitral position and in detecting prosthetic dysfunction, especially when prosthetic obstruction is present.     

Role of transoesophageal echocardiography in the diagnosis and management of aortic root abscess.

OBJECTIVE--To assess and compare the roles of transthoracic and transoesophageal echocardiography in the diagnosis and management of an aortic root abscess. DESIGN--To select patients with echocardiographic diagnosis of aortic valve endocarditis with and without an aortic root abscess and correlate this with a retrospective review of surgical and necropsy data. SETTING--Tertiary referral centre at a university teaching hospital. PATIENTS AND METHODS--34 patients with confirmed aortic valve endocarditis were treated over a four and a half year period. All patients underwent both transthoracic and transoesophageal echocardiography with 17 patients having biplane or multiplane imaging. RESULT--11 patients (32%) had an aortic root abscess. Transthoracic echocardiography identified four cases of aortic root abscess whereas transoesophageal echocardiography correctly detected all 11 cases and also detected complications including mitral aortic intervalvar fibrosa fistula in two patients and right atrial involvement in another two patients. Only biplane imaging was able to show an anterior aortic root abscess in one patient and the circumferential involvement of the aortic annulus in another two patients. All patients with an aortic root abscess were treated surgically after transoesophageal echocardiographic diagnosis. After operation, prosthetic aortic regurgitation was present in seven patients and a repeat operation was performed in three patients. Only transoesophageal echocardiography detected a postoperative aorto-right atrial fistula in two patients and recurrence of the root abscess in another. There were five deaths in hospital (45%). CONCLUSIONS--Compared with transthoracic echocardiography, transoesophageal echocardiography was more sensitive and more specific for the early diagnosis of aortic root abscess and its complications and facilitated both the preoperative and postoperative management of these patients. Biplane and multiplane imaging provide additional diagnostic information. All patients with suspected aortic valve endocarditis should have an early transoesophageal echocardiographic study.     

Diagnosis of prosthetic heart valve thrombosis. The respective values of transthoracic and transoesophageal Doppler echocardiography

Early diagnosis of acute prosthetic thrombosis remains a challenge,in 20 patients with 23 thrombosed cardiac valves, we evaluatedthe respective value of transthoracic (TTE) and transoesophageal(TEE) Doppler echocardiography. According to the presence orabsence of prosthetic obstruction by continuous-wave Doppler,prostheses were separated into two groups. Group 1 included nine thrombosed prostheses (8 mitral, 1 aortic)with severe obstruction. All patients presented with severesymptoms of heart failure. Transthoracic Doppler echocardiographyallowed immediate diagnosis of prosthetic thrombosis, even incritically ill patients, showing (1) eccentric transprostheticcolour flow jets in all eight mitral prostheses, (2) severeobstruction on Doppler examination (mean gradient = 18 to 36mmHg in eight mitral prostheses, and 69 mmHg in one aortic valve),and (3) direct echocardiographic evidence of thrombosis (i.e.thrombus or abnormal disc or leaflet motion) in four patients.All nine patients were immediately treated by surgery (n=8)or fibrinolysis (n =1) on the basis of TTE results only. TEEallowed better visualization of thrombus and restricted leafletor disc motion, but had little influence on patient management. Group 2 included 14 thrombosed prostheses (10 mitral, 4 aortic)with mild or absent obstruction, in three patients with massivemitral prosthetic thrombosis, an associated minimal thrombosisof a prosthetic aortic valve was found at surgery, but was detectedneither by TTE, nor by TEE. The 11 remaining patients presentedwith isolated partial mitral (n = 10) or aortic (n = 1) thrombosis.Clinical presentation was fever, cerebral embolism, or milddyspnoea, but no heart failure. TTE was normal in all. Continuous-waveDoppler showed normal prosthetic function in five patients andmild obstruction in six. TEE allowed diagnosis of prostheticthrombosis in all, showing an abnormal mobile echo around theprosthesis, despite normal disc or leaflet motion. In conclusion, transthoracic Doppler echocardiography is thediagnostic procedure of choice in patients with severely obstructiveprosthetic thrombosis, while the transoesophageal approach appearspromising in partial thrombosis with mild or absent obstruction.