Improved detection of infective endocarditis with transesophageal echocardiography.

The incremental advantage of transesophageal echocardiography was determined by comparing results of paired transthoracic and transesophageal echocardiographic examinations performed in 61 patients for evaluation of suspected infective endocarditis. According to clinical and pathologic data, 31 of 61 (51%) patients had finding that were positive for infective endocarditis. Studies were graded as positive or negative for vegetations and were also graded for image quality. The sensitivity of transesophageal echocardiography in detecting vegetations was 88% versus 30% for transthoracic studies (p less than 0.01). For patients with aortic valve infective endocarditis, transesophageal sensitivity was 88% versus 25% for transthoracic sensitivity, because transesophageal echocardiography successfully separated vegetations from chronic valve disease caused by sclerosis or calcification (p less than 0.01). For patients with mitral valve infective endocarditis, transesophageal sensitivity was 100% versus 50% for transthoracic sensitivity, because transesophageal echocardiography distinguished vegetations from myxomatous changes or detected vegetations on prosthetic valves (p less than 0.01). Thus transesophageal echocardiography improves recognition of infective endocarditis, particularly in the presence of underlying valvular disease.     

The Potential Impact of Contemporary Transthoracic Echocardiography on the Management of Patients with Native Valve Endocarditis: A Comparison with Transesophageal Echocardiography

Background: Between 1987 and 1994, several studies demostrated transthoracic echocardiography (TTE) to be less sensitive than transesophageal echocardiography (TEE) in detecting native valve endocarditis. Recent technologic advances, especially the introduction of harmonic imaging and digital processing and storage, have improved TTE image quality. The aim of this study was to determine the diagnostic accuracy of contemporary TTE. Methods: Between 2003 and 2007, 75 patients underwent both TTE and TEE for clinically suspected infective endocarditis. The diagnostic accuracy of TTE was assessed using transesophageal echocardiography as the gold standard for diagnosis of endocarditis. Results: Of the 75 patients in this study, 33 were found to be positive by TEE. The sensitivity for detection of infective endocarditis by TTE was 81.8%. It provided good image quality in 81.5% of cases; in these patients sensitivity was even greater (89.3%). Conclusion: Contemporary TTE has improved the diagnostic accuracy of infective endocarditis by ameliorating image quality; it provides an accurate assessment of endocarditis and may reduce the need for TEE.     

Can structured clinical assessment using modified Duke's criteria improve appropriate use of echocardiography in patients with suspected infective endocarditis?

BACKGROUND: Although echocardiography has been incorporated into the diagnostic algorithm of patients with suspected infective endocarditis, systematic usage in clinical practice remains ill defined. OBJECTIVE: To test whether the rigid application of a predefined standardized clinical assessment using the Duke criteria by the research team would provide improved diagnostic accuracy of endocarditis when compared with usual clinical care provided by the attending team. METHODS: Between April 1, 2000 and March 31, 2001, 101 consecutive inpatients with suspected endocarditis were examined prospectively and independently by both teams. The clinical likelihood of endocarditis was graded as low, moderate or high. All patients underwent transthoracic echocardiography and appropriate transesophageal echocardiography if deemed necessary. All diagnostic and therapeutic outcomes were evaluated prospectively. RESULTS: Of 101 consecutive inpatients (age 50+/-16 years; 62 males) enrolled, 22% subsequently were found to have endocarditis. The pre-echocardiographic likelihood categories as graded by the clinical and research teams were low in nine and 37 patients, respectively, moderate in 83 and 40 patients, respectively, and high in nine and 24 patients, respectively, with only a marginal agreement in classification (kappa=0.33). Of the 37 patients in the low likelihood group and 40 in the intermediate group, no endocarditis was diagnosed. In 22 of 24 patients classified in the high likelihood group, there was echocardiographic evidence of vegetations suggestive of endocarditis. Discriminating factors that increased the likelihood of endocarditis were a prior history of valvular disease, the presence of an indwelling catheter, positive blood cultures, and the presence of a new murmur and a vascular event. General internists, rheumatologists and intensive care physicians were more likely to order echocardiography in patients with low clinical probability of endocarditis, of which pneumonia was the most common alternative diagnosis. CONCLUSION: Although prediction of clinical likelihood varies between observers, endocarditis is generally found only in those individuals with a moderate to high pre-echocardiographic clinical likelihood. Strict adherence to indications for transthoracic echocardiography and transesophageal echocardiography may help to facilitate more accurate diagnosis within the moderate likelihood category. Patients with low likelihood do not derive additional diagnostic benefit with echocardiography although other factors such as physician reassurance may continue to drive diagnostic demand.     

Clinical information determines the impact of transesophageal echocardiography on the diagnosis of infective endocarditis by the duke criteria

BACKGROUND: Although transesophageal echocardiography (TEE) is more sensitive than transthoracic echocardiography (TTE) in detecting echocardiographic evidence of infective endocarditis (IE), the impact of TEE on the clinical diagnosis of IE has not been clearly delineated. METHODS AND RESULTS: We studied 112 patients with 114 suspected episodes of IE over a 6-year period who underwent both TTE and TEE during their diagnostic evaluation. Using the results of these studies along with clinical and microbiologic data, we attempted to determine the incremental value of TEE to the Duke Endocarditis Diagnostic Criteria. Patients were initially classified into a diagnostic category of the Duke criteria with TTE data, and then the diagnostic classification was reconsidered with TEE data. A diagnostic category reassignment occurred in 25 of 114 episodes of IE evaluated when TEE results were incorporated into the evaluation with the Duke criteria (22 patients were reclassified from possible IE to definite IE whereas 3 patients were reclassified from rejected to possible IE). Diagnostic reclassification occurred in 9 (11%) of the 80 episodes of suspected IE with native cardiac valves and 13 (34%) of 34 episodes with prosthetic cardiac valves. Most patients reclassified from possible IE to definite IE with TEE data (19 of 22) had an intermediate clinical likelihood of IE, whereas 92% of patients had negative TTE results. Pathologic examination of valvular tissue in 22 of the 114 episodes of suspected IE revealed that the positive predictive value of the Duke criteria with TEE data for diagnosis of IE was 85% in patients with native valves and 89% in patients with prosthetic valves. CONCLUSIONS: When clinical evidence of IE is present, TEE improves the sensitivity of the Duke criteria to diagnose definite IE. TEE data appears to be especially useful for the diagnostic evaluation of patients with suspected IE who have prosthetic valves.     

Value of transesophageal echocardiography as an adjunct to transthoracic echocardiography in evaluation of native and prosthetic valve endocarditis

To determine if transesophageal echocardiography provides better visualization of valvular vegetations than transthoracic echocardiography, we used both methods to evaluate 24 consecutive patients (mean age, 54 years; 15 female patients and nine male patients) referred for symptoms suggestive of infectious endocarditis. Ten of the 24 patients had one or more valvular prostheses. Echocardiograms were classified as positive or negative based on visualization of valvular vegetations or abscesses. Of ten patients with a final diagnosis of infectious endocarditis on extended follow-up, transthoracic echocardiography was positive in five patients. Transesophageal echocardiography not only yielded abnormal findings in all ten of these patients, but also revealed additional information in four of the five patients with abnormal transthoracic echocardiographic examinations. Among the 14 patients who, on subsequent follow-up, were found not to have infectious endocarditis, transthoracic echocardiography was normal in 13 and falsely abnormal in one. Transesophageal echocardiography revealed no evidence of infectious endocarditis in any of these patients. The ten patients who were determined to have infectious endocarditis all had positive blood cultures and no alternative cause for their clinical presentation; in seven patients in this group who underwent operative or postmortem evaluation, infectious endocarditis was confirmed. All patients without infectious endocarditis were demonstrated to have other causes for their clinical presentation. We conclude that transesophageal echocardiography is a highly valuable test in the work-up of patients with suspected infectious endocarditis, especially those patients with inconclusive or normal transthoracic echocardiograms. In addition, transesophageal echocardiography may be of benefit to patients with previously documented infectious endocarditis and a complicated clinical course in whom additional cardiac lesions are suspected but not demonstrated by transthoracic echocardiography.     

Echocardiography in patients with suspected endocarditis: a cost-effectiveness analysis.

PURPOSE: We sought to determine the appropriate use of echocardiography for patients with suspected endocarditis. PATIENTS AND METHODS: We constructed a decision tree and Markov model using published data to simulate the outcomes and costs of care for patients with suspected endocarditis. RESULTS: Transesophageal imaging was optimal for patients who had a prior probability of endocarditis that is observed commonly in clinical practice (4% to 60%). In our base-case analysis (a 45-year-old man with a prior probability of endocarditis of 20%), use of transesophageal imaging improved quality-adjusted life expectancy (QALYs) by 9 days and reduced costs by $18 per person compared with the use of transthoracic echocardiography. Sequential test strategies that reserved the use of transesophageal echocardiography for patients who had an inadequate transthoracic study provided similar QALYs compared with the use of transesophageal echocardiography alone, but cost $230 to $250 more. For patients with prior probabilities of endocarditis greater than 60%, the optimal strategy is to treat for endocarditis without reliance on echocardiography for diagnosis. Patients with a prior probability of less than 2% should receive treatment for bacteremia without imaging. Transthoracic imaging was optimal for only a narrow range of prior probabilities (2% or 3%) of endocarditis. CONCLUSION: The appropriate use of echocardiography depends on the prior probability of endocarditis. For patients whose prior probability of endocarditis is 4% to 60%, initial use of transesophageal echocardiography provides the greatest quality-adjusted survival at a cost that is within the range for commonly accepted health interventions.     

Transesophageal echocardiography (TEE) in the evaluation of infective endocarditis

Echocardiography is an essential tool for the modern diagnosis and management of infective endocarditis and its complications. The negative predictive value of surface imaging is inadequate to rule out endocarditis in most instances; diagnostic sensitivity is improved by way of the transesophageal approach. The clinical scenario and pretest probability of disease should guide the use of transesophageal versus transthoracic imaging. Those at high risk for endocarditis or its complications in particular should undergo early TEE. Serial studies may be required to guide management. In the setting of an initially negative echocardiographic study, a repeat examination is indicated if the clinical suspicion of endocarditis persists or if the clinical picture changes. Combined transthoracic echocardiography and TEE may supply complementary information useful in management and follow-up. As most published research predates recent advances in imaging, the impact of changing technology, such as harmonic and three-dimensional imaging, in the management of endocarditis is yet to be determined.     

The limitations of echocardiography in the overall diagnosis of the morphological lesions associated with infective endocarditis: comparison of echocardiographic and surgical findings

Echocardiography is commonly accepted as the method of choice for the non-invasive diagnosis of vegetations and other lesions associated with infective endocarditis. To assess the accuracy of echocardiography in the overall diagnosis of the morphological cardiac lesions we retrospectively analyzed and compared the preoperative echocardiographic data with the surgical findings of 120 consecutive cases operated for infective endocarditis. Transthoracic echocardiography (TTE) was used in 60 cases (51 with native and 9 with prosthetic valves), both TTE and transesophageal echocardiography (TEE) in 50 (26 with native and 24 with prosthetic valves) and only TEE in 10 patients who underwent emergency surgery. The echocardiographic diagnosis was correct in all the cases, but incomplete in 26 (16 with native and 10 with prosthetic valves). Most of the incomplete diagnoses occurred regarding vegetations, perforations of the valvular leaflets and perivalvular abscesses. There were no differences between aortic or mitral valves (14/66 vs 11/60; p = ns), native or prosthetic (16/79 vs 10/37; p = ns), TTE or TEE (13/60 vs 13/60; p = ns); however, TEE was performed in more complex cases and in severely ill patients. In six of the incomplete diagnoses, echocardiography preceded surgery by one week or more, and in six the mistakes were not confirmed by the reviewer. In conclusion, our study suggests that an echocardiographic diagnosis of endocarditis may be correct but sometimes incomplete. In patients without prosthetic valves who have a technically-adequate transthoracic echocardiogram, transesophageal echocardiography is not indispensable but should be chosen from time to time. However, the patients with endocarditis and no contraindication to the transesophageal procedure should undergo both transesophageal and transthoracic echocardiography before surgery in order to obtain as much and the most definite information possible. An echocardiographic study should be repeated just before any surgical procedures in patients with active endocarditis. Finally, it needs to be emphasized that the training and clinical judgement of the operator performing the study are important elements determining the results of echocardiographic study.     

Clinical criteria and the appropriate use of transthoracic echocardiography for the exclusion of infective endocarditis

Background: Clinical guidelines currently suggest that transthoracic echocardiography (TTE) be carried out in all patients with suspected endocarditis, but the use of TTE where there is a low probability of infective endocarditis has a poor diagnostic yield. This screening approach may no longer be appropriate.     

Has Transesophageal Echocardiography Changed the Approach to Patients with Suspected or Known Infective Endocarditis?

Infective endocarditis is still a great clinical challenge. Its diagnosis is difficult to establish, and mortality has remained around 30%. Early diagnosis and optimal treatment are crucial fo prognosis improvement. Echocardiography plays an indispensable role in the management of this disease, especially with the recently introduced approach, transesophageal echocardiography (TEE). TEE can overcome the limitations of transthoracic echocardiography (TTE) and is superior to TTE in almost every way in providing earlier and more information for the diagnosis and treatment of infective endocarditis. TEE detects valve vegetations with much higher sensitivity and specificity than TTE. It can demonstrate smaller vegetations in the early stage of the disease and vegetations on atypical locations (e.g., mitral valve annulus), and provides detailed characterization of vegetations (e.g., location, size, mobility, and changes during treatment). Such information is of great prognostic value and may help in selecting proper treatment. TEE is more sensitive for detecting complications, such as mitral valve perforation, abscess, and subaortic complications, which respond poorly to medicine and for which timely surgery may be the best treatment. For those with prosthetic valve endocarditis, TEE is especially useful because TTE is greatly limited by the acoustic shadow of prostheses. Both positive and negative results of TEE examination are valuable for confirming or excluding infective endocarditis. TEE also plays a unique role in intraoperative monitoring and can assess surgical results before the chest is closed. TEE has become an invaluable tool for the diagnosis and management of patients with suspected or known infective endocarditis.     

A sinus of Valsalva aneurysm ruptured into the right atrium secondary to aortic endocarditis. The usefulness of transthoracic and transesophageal echocardiography]

We present a case of a sinus of Valsalva aneurysm ruptured into right atrium secondary to aortic endocarditis. Early surgical procedure was indicated bases on transthoracic echocardiography. This technique demonstrated a abscess image enlarged into the right atrium and color Doppler showed a turbulent flow from aortic valve to right atrium. Cardiac surgery was performed with transesophageal echocardiography monitoring. This technique allowed anatomical and functional aortic valve evaluation and the abscess location and extension. This case shows the value of transthoracic and transesophageal color Doppler echocardiography in the diagnosis and management of patients with complications secondary to infective endocarditis.     

Comparison of transthoracic and transesophageal echocardiography in evaluation of 47 Starr-Edwards prosthetic valves.

OBJECTIVES. Our objectives were to characterize by transesophageal echocardiography the normal appearance of the Starr-Edwards prosthetic heart valve and to compare the utility of transesophageal and transthoracic echocardiography in detection of valve abnormality. BACKGROUND. The Starr-Edwards prosthetic heart valve, the first mechanical valve to be used, has demonstrated excellent durability. METHODS. Fifty transthoracic and transesophageal echocardiographic studies on 37 patients with 47 Starr-Edwards prosthetic valves were analyzed retrospectively. Six cases of surgically confirmed infective endocarditis were studied. RESULTS. Vegetation or abscess formation, or both, was identified by transesophageal echocardiography in all six cases of infective endocarditis but was found in only one of these cases by transthoracic echocardiography. Thrombus was detected by transesophageal echocardiography in 9 of 11 patients with transient ischemic attacks or stroke and in 2 patients by transthoracic echocardiography with 3 confirmed at surgery. In 26 of the 30 patients with a mitral Starr-Edwards valve, the valve demonstrated a trivial or mild "closing volume" early systolic or holosystolic leak on transesophageal echocardiography alone. Transthoracic evaluation identified significant mitral regurgitation in six of the eight patients who had this finding on transesophageal echocardiography. Serial studies were performed to assess response to treatment or need for surgical intervention in eight patients. Seventeen valves have been implanted for 12 years; six of these had significant leakage without apparent cause, a finding not observed more recently implanted valves. CONCLUSIONS. These observations demonstrated the unique utility of transesophageal echocardiography in patients with Starr-Edwards prosthetic valve dysfunction, endocarditis or thrombus formation, and of the clear superiority of transesophageal echocardiography over transthoracic echocardiography in these situations.     

Echodetection of disseminated endocardial vegetations in a patient with active IV drug abuse

Infective endocarditis is a known complication of intravenous (IV) drug abuse and typically involves cardiac valves, sparing the myocardial endocardium. We present the case of a young IV drug using patient who developed sepsis. Although cardiac symptoms and signs were minimal, an echocardiogram was done as patient had a history of IV drug abuse and was in sepsis. Echocardiogram demonstrated disseminated vegetations involving the left ventricular and right ventricular endocardium while sparing the valves. Although diagnosis of infective endocarditis was made on two-dimensional transthoracic echocardiogram, two-dimensional and three-dimensional transesophageal echocardiograms demonstrated the pattern of endocarditis with clarity. This patient had severe sepsis and bacteremia with Methicillin sensitive Staphylococcus aureus.     

Transthoracic echocardiography (TTE): sufficiently sensitive screening test for native valve infective endocarditis (IE)

We recently reviewed our experience with paired transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE) studies for the diagnosis of native valve infective endocarditis. In patients with normal heart valves, we demonstrated that a normal TTE effectively rules out infective endocarditis and a TTE is unnecessary. In patients with abnormal heart valves, a TEE did not enhance the diagnostic yield in most patients (12/15). We reviewed 87 paired TTEs and TEEs, that is, TEE with a preceding TTE performed for the evaluation of native valve IE. Of 87 paired echocardiograms, 72 of 87 had normal TTEs and TEEs, with no evidence of a vegetation indicative of infective endocarditis. A total of 15 of 87 TTEs had thickened/calcified valves without a definite vegetation. Of these, only 3 of 15 were subsequently shown to have a vegetation indicative of endocarditis by TEE. In patients with possible native valve infective endocarditis, before blood culture results are known, a negative TTE was sufficiently specific to rule out native valve infective endocarditis. Our data showed that the negative predictive value of a normal TTE in the evaluation of possible native valve endocarditis is 90% or greater. In those with some valve abnormality (ie, thickened/calcified heart valves), subsequent TTE did not materially increase vegetation detection.     

Role of echocardiography in the diagnosis and management of infective endocarditis

Infective endocarditis is a life-threatening disease with significant morbidity and mortality. Accurate and early diagnosis for initiation of effective treatment is essential in improving patient outcome. Echocardiography is currently the primary modality for the detection of vegetations and cardiac complications that result from endocarditis. Technological advances in echocardiography, particularly the development of transesophageal echocardiography (TEE), have revolutionized the diagnosis and management of infective endocarditis. With the enhanced resolution provided by TEE, vegetations and paravalvular complications can be reliably detected. Transthoracic and transesophageal echocardiography provides complementary information for patient management and follow-up, and is best used in conjunction with clinical data. By means of its high sensitivity and negative predictive value, TEE is essential in the evaluation of prosthetic valve endocarditis and the paravalvular complications of IE. All patients with suspected infective endocarditis should undergo transthoracic echocardiography, and most of these patients should also undergo TEE evaluation. The role of new technology such as harmonic and three-dimensional imaging is yet to be determined.     

Transesophageal echocardiography in an emergency setting. A district general hospital experience.

Transesophageal echocardiography is an extremely useful technique for the study of various cardiovascular pathologies. In the particular setting of emergency, it is of great value for prompt diagnosis and appropriate therapy. It was our aim to evaluate, in our hospital, the benefits obtained by the use of transesophageal echocardiography in an emergency setting. We retrospectively studied patients who underwent transesophageal echocardiography (TEE) in an emergency setting, from June 1997 to December 2002, evaluating demographic characteristics, indication to perform TEE, benefit obtained (diagnosis or exclusion of initial diagnosis), and technique-related complications. There were 97 transesophageal echocardiograms performed in an emergency setting in the period under consideration, accounting for 19.3% of the total number of exams. Fifty-two patients (53.6%) were male, mean age 63.9 +/- 12.7. Nineteen patients (19.6%) were on assisted ventilation. The indications to perform TEE were: possible massive or submassive pulmonary thromboembolism in 32 patients (33.0%); suspected aortic dissection in 19 (19.6%); shock with inconclusive transthoracic echocardiogram in ten (10.3%); possible endocarditis in eight (8.2%); possible prosthetic valve dysfunction in seven (7.2%); intracardiac mass in six (6.2%); search for cardiac source of embolism in five (5.2%); possible mechanical complication of acute myocardial infarction in four (4.1%); pre-electrical cardioversion study in four patients with atrial fibrillation (4.1%); and suspected congenital heart disease in two (2.1%). TEE examination yielded additional information and helped in the therapeutic decision in 88 patients (90.7%), leading to a diagnosis in 49 (50.6%), which was different from the initial diagnostic hypothesis in four, and exclusion of the suspected diagnosis in 39 (40.1%). There was only one minor complication (1.0%) and no TEE-related mortality. We concluded that transesophageal echocardiography is an extremely useful and safe cardiovascular diagnostic technique in an emergency setting in a district general hospital, enabling a diagnosis to be reached or excluded in almost all patients, which is essential for implementing appropriate therapy.     

Endokarditisdiagnostik heute: Duke-Kriterien oder klinische Einschätzung?

DIAGNOSIS OF INFECTIVE ENDOCARDITIS: Due to the complexity of the clinical diagnosis of infective endocarditis, standardized diagnostic schemes have been developed to improve the sensitivity and specificity of the diagnosis. The Von Reyn criteria, introduced in 1981 relied mainly on clinical, microbiological, and histopathological criteria and were for more than 10 years regarded as the diagnostic goldstandard. However, the Von Reyn criteria have a sensitivity of merely about 30-60% and their reliability is especially low in case of negative blood cultures. ROLE OF ECHOCARDIOGRAPHY: An important step towards an improved sensitivity and specificity in the diagnosis of infective endocarditis was the introduction of transesophageal echocardiography, which is far more sensitive and specific in this indication than the transthoracic approach. Besides the early detection of vegetations and complications such as abscess formation, valvular destructions or perforations, echocardiography may be helpful to identify patients at risk for a prolonged healing, embolization, or may be also used to monitor the therapeutic progress. THE DUKE CRITERIA: Implementation of echocardiography into the Duke criteria, introduced in 1994, yielded as expected, a significant higher sensitivity of up to 100% than the von Reyn criteria with an almost identical specificity. Thus, the latter were completely replaced by the Duke criteria in clinical practice. MODIFICATIONS OF THE DUKE CRITERIA: Nevertheless, some uncertainty remains, especially in culture-negative endocarditis which has led to certain modifications of the Duke criteria. Besides the implementation of unspecific inflammatory parameters such as the C-reactive protein, a positive Q-fever serology has been added and any S. aureus bacteremia is now judged as major criterion. Although a prospective evaluation has to be awaited, these modifications appear promising and should be implemented into clinical practice. CONCLUSIONS: The Duke criteria are currently the most sensitive tool in the diagnosis of infective endocarditis. It can be expected that they will help to significantly shorten the time to diagnosis, and may, thus, improve the clinical outcome.     

Criteria for the diagnosis of endocarditis and the role of echocardiography

When infective endocarditis is a diagnostic possibility, echocardiography permits noninvasive imaging of cardiac structures. As involvement of the endocardium is a sine qua non of endocarditis, echocardiography may assist in its diagnosis by demonstrating such involvement. The ability of echocardiography to detect the intracardiac manifestations of infective endocarditis has continued to improve, especially with the introduction of transesophageal imaging. This article will discuss some of the echocardiographic findings in endocarditis and elucidate the incorporation of these findings in the new Duke criteria for the diagnosis of endocarditis.     

Diagnosis of papillary muscle rupture after acute myocardial infarction by transthoracic and transesophageal echocardiography

The sensitivity of transthoracic echocardiography to visualize the structural abnormality of papillary muscle rupture (PMR) after acute myocardial infarction can be anticipated to average about 50%; therefore, we evaluated five patients exhibiting the condition with both transthoracic and transesophageal echocardiography. The use of the two imaging techniques resulted in the fact that no instance of PMR was missed. Using transthoracic echocardiography in two patients and transesophageal echocardiography in four, the ruptured papillary muscle was visualized directly. Mitral insufficiency as an indirect sign was observed in all patients. In one patient the papillary muscle rupture developed in a mitral valve previously affected by endocarditis. All patients underwent mitral valve replacement and coronary artery bypass grafting. The diagnosis was confirmed at surgery in all patients. Four patients died in hospital, the fifth 5 months later. We recommend that transesophageal echocardiography be performed in patients with suspected PMR if transthoracic echocardiography does not provide an unequivocal diagnosis.     

The pitfalls of transthoracic echocardiography. A case of eustachian valve endocarditis

A case of infective endocarditis involving the vestigial eustachian valve is presented and the available English medical literature is reviewed. Only 5 prior cases have been reported: 4 of those required transesophageal echocardiography for diagnosis, and the other was found at autopsy. This clinical entity is routinely missed on transthoracic echocardiography. Injection drug use is a common predisposing factor, and Staphylococcus aureus is the most commonly identified organism. This report broadens the differential diagnosis of endovascular infections in injection drug users and highlights the importance of transesophageal echocardiography for diagnosis in selected patients.