(Circulation. 1996;93:730-736.)
© 1996 American Heart Association, Inc.
Articles |
Diagnostic Value of Echocardiography in Suspected Endocarditis
An Evaluation Based on the Pretest Probability of Disease
Presented in part at the 44th Annual Scientific Session of the American College of Cardiology, New Orleans, La, March 19-22, 1995.
From the Cardiovascular Division (J.R.L., R.A.C., J.M.D., S.K.) and the Divisions of Biostatistics (R.D.A.) and Infectious Diseases (W.M.S.), University of Virginia School of Medicine, Charlottesville.
Correspondence to Sanjiv Kaul, MD, Cardiovascular Division, Box 158, University of Virginia Medical Center, Charlottesville, VA 22908.
 |
Abstract |
|---|
 Top Abstract IntroductionMethods Results Discussion References |
|---|
Background We hypothesized that for the diagnosis of endocarditis, (1) transthoracic echocardiography (TTE) would be most valuable in patients with an intermediate clinical probability of the disease and (2) transesophageal echocardiography (TEE) would be most useful in patients with an intermediate probability when TTE either does not yield an adequate study or indicates an intermediate probability of endocarditis. We also sought to investigate the influence of echocardiographic results on antibiotic usage and its duration.
Methods and Results TTE and TEE were performed in 105 consecutive patients with suspected endocarditis. Patients were classified as having either low, intermediate, or high probability of endocarditis on the basis of clinical criteria and separately on the basis of both TTE and TEE findings. TTE and TEE classified the majority (82% and 85%, respectively) of the 67 patients with a low clinical probability of endocarditis as having a low likelihood of the disease. Of the 14 patients with intermediate clinical probability, 12 had technically adequate TTE studies; 10 of these (83%) were classified as either high or low probability. All patients with intermediate clinical probability were classified as high or low probability by TEE. The majority of the 24 patients with high clinical probability were placed in the low-likelihood category by echocardiography (15 by TTE and 12 by TEE). There was concordance between TTE and TEE in 83% of all cases. TEE was useful for the diagnosis of endocarditis in patients with prosthetic valves and in those in whom TTE indicated an intermediate probability; these constituted <20% of patients in our study. The course of antibiotic therapy was influenced only by the clinical profile and not by the echocardiographic results.
Conclusions Echocardiography should not be used to make a diagnosis of endocarditis in those with a low clinical probability of the disease. In those with an intermediate or high clinical probability, TTE should be the diagnostic procedure of choice. TEE for the diagnosis of endocarditis should be reserved only for patients who have prosthetic valves and in whom TTE is either technically inadequate or indicates an intermediate probability of endocarditis.
Key Words: echocardiography • endocarditis • diagnosis
|
Introduction |
|---|
|
TopAbstractIntroductionMethods Results Discussion References |
|---|
Two-dimensional echocardiography has the ability to detect vegetations and their associated complications in patients with endocarditis. According to the population studied, transthoracic echocardiography (TTE), which has been used in clinical practice for the past 15 years, has been reported to have a sensitivity of anywhere from 40% to 80% for the detection of vegetations.1 2 3 4 5 6 7 8 With transesophageal echocardiography (TEE), the image quality is better because of no interposing lung tissue and the higher transducer frequencies used. Hence, it has been reported to be superior to TTE for the detection of vegetations and their associated complications.8 9 10 11 12 13 14 15 16
Echocardiography is often requested in patients with fever and/or a murmur who have a low probability of endocarditis. By the same token, it is also requested in patients in whom the diagnosis is virtually certain. Patients with an intermediate probability of endocarditis constitute a minority of those undergoing echocardiography. The practical value of echocardiography in these different populations has not been investigated.
We hypothesized that the value of echocardiography for the diagnosis of endocarditis would be greatest in patients with an intermediate clinical probability of the disease. According to the same logic, we also postulated that TEE would be most useful in patients with an intermediate probability of endocarditis in whom TTE either does not yield a technically adequate study or indicates an intermediate probability. We also sought to determine the influence of echocardiographic findings on the use and duration of antibiotic treatment in patients with suspected endocarditis.
|
Methods |
|---|
|
TopAbstractIntroductionMethods Results Discussion References |
|---|
Patient Population
Between October 1992 and June 1994, 105 consecutive patients who were referred to the University of Virginia echocardiography laboratory for evaluation of suspected endocarditis were studied prospectively. All patients gave informed consent to participate in the study, the protocol for which was approved by the Human Investigation Committee at the University of Virginia. There were 59 men and 46 women ranging in age from 16 to 88 years. All patients were categorized as having a low, intermediate, or high probability of endocarditis on the basis of a modification of previously published definitions (Table 1
).17 The
duration of antibiotic therapy
was determined for each patient from the hospital records.
|
Echocardiography
All patients underwent TTE and TEE within 36
hours of each
other; in 89%, both procedures were performed in tandem during the
same session. TTE was performed with a 2.5- or 3.5-MHz phased-array
transducer. Patients fasted for more than 4 hours before TEE, which was
performed under local pharyngeal anesthesia; the majority
of patients also received intravenous midazolam (0.5 to 4.0
mg). A 5-MHz phased-array transducer (either biplane or multiplane)
was used for the transesophageal examination, which
consisted principally of two-dimensional imaging and color flow
mapping and was performed without any complications within 15 minutes
in all patients. The information obtained on
echocardiography was made available to the
referring physicians.
All echocardiograms were evaluated later during reading sessions by two observers who were blinded to the clinical information. TTE and TEE studies were read in random order on separate occasions, which ensured that the results of the TTE study on a patient were not known to the observers while they were reading the TEE study on the same patient. TTE studies were defined as technically inadequate if both observers deemed the quality of the images to be insufficient to gain diagnostic information regarding the presence or absence of vegetations or their complications. Findings on TTE and TEE were separately categorized as indicating high, intermediate, or low probability for endocarditis as follows: high, any definite vegetation and/or abscess or probable vegetation with evidence of otherwise unexplained valvular dysfunction (greater than mild regurgitation or a paravalvular prosthetic leak); intermediate, a probable vegetation without evidence of unexplained valvular dysfunction; and low, no evidence of vegetation or abscess or a possible vegetation without any evidence of regurgitation. Echocardiographic evidence of vegetation or abscess was determined according to previously defined criteria.18 19 20
Statistical Methods
Comparisons between groups were made by
either a
2 or unpaired Student's t test or
ANOVA. Comparisons of reliability between various
diagnostic methods were based on 
statistics and
provided a means for calculating agreement that occurred in excess of
chance alone. Cox regression models and Kaplan-Meier analysis
were used to evaluate the impact of the clinical criteria and either
echocardiographic technique on the use and duration of
antibiotic therapy. All tests were two-sided, and a value of
P<.05 was considered to be statistically
significant.21
|
Results |
|---|
|
TopAbstractIntroductionMethods Results Discussion References |
|---|
Clinical Findings
According to the criteria presented in Table 1
, 67
patients were deemed to have a low, 14 to have an intermediate, and 24
to have a high probability of endocarditis. The historical data were
similar among all subgroups, with the exception of a higher incidence
of previous valvular disease in the
intermediate-probability group (Table 2). The time
from onset of illness to performance of
echocardiography was also similar between the
groups (Table 2). As expected, the presence of many of the
clinical
abnormalities associated with endocarditis increased with a higher
clinical probability of the disease (Table 3). Three of
the 5 patients with negative blood cultures and yet a high clinical
probability of endocarditis were on antibiotics at the time of sample
collection.
|
|
Echocardiographic Findings
There were 12 patients with
technically inadequate TTE studies,
whereas all TEE studies were adequate for interpretation. Vegetations
were identified in 23 patients by each approach, and the prevalence of
vegetations by either echocardiographic approach
increased with increasing clinical likelihood of endocarditis (Fig
1). In 2 of these patients, an abscess was identified by
both approaches, and in 1 additional patient, an abscess was seen on
TEE only. In all patients with an abscess, either a definite or
probable aortic valve vegetation was seen by both techniques. Eight
patients thought to have vegetations on TTE were found to have
nonspecific valvular abnormalities (thickening or
calcification) on TEE. Six of these were subsequently classified as
having a low probability of endocarditis by TEE as opposed to
intermediate (n=5) or high (n=1) probability by TTE.
|
Comparison of Clinical and Echocardiographic
Data
Fig 2A illustrates the
echocardiographic results in the 67 patients with a low
clinical probability of endocarditis. Both TTE and TEE classified the
majority of these patients as low probability (47 of the 57
interpretable TTE and 57 of the 67 TEE studies). Of the remaining 10
patients with low clinical probability who were classified as
intermediate or high probability by
echocardiography, approximately half had suspected
prosthetic valve endocarditis. The remainder were deemed not to
have a final diagnosis of endocarditis despite the
echocardiographic findings.
|
Fig 2B depicts the
echocardiographic results in the 14
patients with an intermediate clinical probability of endocarditis. TTE
reclassified the majority of the patients (10 of the 12 interpretable
studies) into either low or high probability, whereas TEE classified
all patients as either high or low probability.
Fig 2C
shows the echocardiographic results in the 24
patients with a high clinical probability of endocarditis.
Approximately half of these were classified as low probability by
echocardiography (15 by TTE and 12 by TEE). In many
of these, however (7 patients), another source of infection was
identified later in their hospital course. These patients originally
had a high clinical probability of endocarditis because of the presence
of nonspecific vascular phenomena (petechiae, embolism) and a murmur.
The rest had significant valvular regurgitation
due to structural abnormalities of the valve (flail leaflet or
rheumatic, sclerotic, or prosthetic valve) without evidence of
concurrent endocarditis. No patient with another source of infection
was classified as having intermediate or high likelihood of
endocarditis by either TTE or TEE.
Evaluation of Prosthetic Valves
Of the 17 patients with
prosthetic valves, 12 were
classified as low, 2 as intermediate, and 3 as high probability for
endocarditis on clinical grounds. TTE classified only 2 of the 11
interpretable studies in patients with low clinical probability into
either intermediate or high probability, whereas TEE classified 5 of
the 12 patients as such. Both approaches classified the 2 patients with
intermediate clinical probability as low probability for endocarditis.
The 3 patients with high clinical probability were classified as low
probability for endocarditis; another source of infection was later
identified in all of them.
Comparison of TTE and TEE
In those with interpretable
studies, there was 83% agreement
between TTE and TEE for determining the likelihood of endocarditis.
Concordance between the two techniques was high in all clinical
categories and was significantly greater than could have occurred by
chance alone (Table 4). The probability of chance
agreement varied among the three clinical probability groups because of
the variable prevalence of positive
echocardiographic findings. The greatest discordance
was noted in the 10 patients with an intermediate probability of
endocarditis on TTE, 7 of whom were reclassified as low or high
probability by TEE. As depicted in Fig 3, the
distribution of valves showing possible, probable, or definite
vegetations was similar for both techniques. Concordance between TTE
and TEE for either presence or absence of vegetations was high, with an
overall concordance of 96% for all four valves.
|
|
Implications for Management
The probability of endocarditis
based on clinical criteria was the
only variable that predicted the use and duration of antibiotics by
univariate analysis (Fig 4). On
multivariate analysis, the relative likelihood
of being free of antibiotic use was approximately twofold in the low
compared with the high clinical probability group (P<.05).
Neither TTE nor TEE significantly influenced antibiotic use in this
patient cohort, although there was a trend for increased antibiotic use
in those who had a high probability of endocarditis on the basis of
TEE. Four patients underwent valve replacement (3 of native and 1 of
prosthetic valve) because of unremitting congestive heart
failure. Three of these patients had a high probability of endocarditis
both clinically and by either echocardiographic
approach.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethods Results Discussion References |
|---|
Our results indicate that echocardiography, both TTE and TEE, has a low diagnostic yield in patients with a low clinical probability of endocarditis, who constitute the majority of patients in whom it is requested to "rule out" the condition. We found a concordance between TTE and TEE findings in the majority of our patients. It is only in those in whom TTE suggested an intermediate probability that TEE offered incremental value. The probability of endocarditis on the basis of clinical criteria was the only variable that predicted the use and duration of antibiotic treatment. Neither TTE nor TEE significantly influenced antibiotic use in this patient cohort.
Diagnosis of Endocarditis
Despite advances in technology,
endocarditis remains a clinical
diagnosis. As exemplified by Libman and Celler in 1910,22
the diagnosis rests largely on isolation of the blood-borne
pathogen, a notion still held today.23 In certain subsets
of patients clinically suspected of endocarditis, however, confirmatory
evidence may be lacking, such as in those with
"culture-negative" endocarditis. Such patients may have
already received antibiotics before blood samples are obtained for
microbiological analysis or may have pathogens that cannot be
readily isolated. These patients are in the minority and could benefit
from echocardiography, in which the presence of a
definite vegetation may help confirm the diagnosis.23
In the majority of other patients with endocarditis, however, blood cultures are usually positive. In these patients, it is unlikely that echocardiography can offer any additional information regarding the presence or absence of endocarditis. Certain findings on physical examination, such as splinter hemorrhages, Janeway lesions, or Osler's nodes, increase the likelihood of endocarditis. Similarly, other sources of fever or other sites of infection that are not usually associated with endocarditis make it unlikely that a patient has endocarditis. The clinical picture rarely results in a certain diagnosis, but neither does echocardiography.
Echocardiography in Native Valve
Endocarditis
As is the case with most diagnostic tests, the earlier
studies showing the value of TTE in endocarditis were performed
in highly selected patients in whom the presence or absence of
endocarditis was virtually certain on clinical
grounds.6 8 10 The high positive and
negative predictive
values of the test were influenced by the high pretest likelihood of
having or not having the disease. As the clinical experience increased
and as the test was used more indiscriminately, the predictive value
decreased.14 16 24
More recently, TEE has been tested in selected patients with a high likelihood of endocarditis. Because of its superior imaging capabilities, the level of confidence for determining the presence of a vegetation is higher than that with TTE.8 9 10 11 12 13 14 15 16 This may be particularly relevant for less experienced observers. As can be noted in our study, despite our extensive experience with echocardiography, we also tended to place more patients with abnormal native valves in the intermediate probability category for endocarditis on the basis of TTE. In some of these patients, we were not sure whether a vegetation coexisted with the underlying abnormality, and it was in these patients that TEE provided the greatest advantage. It is important to note, however, that in the majority of patients with abnormal native valves, we were able to determine the likelihood of endocarditis from TTE alone.
Echocardiography in Prosthetic
Valve Endocarditis
We concur with previous
suggestions12 15 25 that
patients with prosthetic valves suspected of having
endocarditis do best by having TEE directly. The clinical picture in
these patients can be atypical, and it seems prudent not to place a
patient with a prosthetic valve and fever in a low probability
category under the criteria used for native valves. Because of
reverberations and attenuation produced by the prosthetic
material, it may not be possible to discern a small vegetation in these
patients by TTE, with the result that these patients tend to be placed
in the intermediate probability category anyway if this approach is
used. TEE offers the greatest value in these patients by more clearly
defining the presence or absence of vegetations.
Influence of Echocardiographic Results on
Antibiotic Course
In the aggregate, it was the clinical suspicion of
endocarditis
that determined the use and duration of antibiotic therapy. Neither
echocardiographic approach significantly influenced
antibiotic use. These results should be interpreted with caution,
however. Patients with an initially high clinical probability of
endocarditis in whom vegetations are not shown by
echocardiography may be treated more aggressively
with antibiotics simply because they have another source of infection.
On the other hand, it can be argued that if the clinical profile and
microbiological results are the primary determinants of antibiotic use,
echocardiographic results play at best a minor role in
this determination.
Limitations of the Study
The incremental value of a test for
making a diagnosis is best
determined when a "gold standard" is available. Short of a
pathology specimen taken either at necropsy, during operation, or from
an embolus, there is no way of making a definitive diagnosis of
endocarditis. Only a probability can be estimated from clinical and
laboratory evidence. Since we were testing the utility of
echocardiography, we could not use a vegetation on
TEE as a gold standard for the presence of a vegetation.
According to the probability theory, a test should not offer additional information when the pretest likelihood of disease is either low or high.26 27 Unlike the group with low clinical probability, however, echocardiography did offer additional diagnostic information in the group with high clinical probability. Although the prevalence of vegetations on echocardiography was highest in this subgroup, they were not seen in at least half of the patients. One possibility is that vegetations were not large enough to be seen on echocardiography. The other, and we believe more likely, explanation is that there is poor discrimination between intermediate and high probability of endocarditis on the basis of clinical grounds alone. For instance, almost all patients in our study who had a high probability of endocarditis according to clinical criteria but in whom echocardiography showed no vegetations had either petechiae or vascular embolic phenomena and were later found to have another source of infection. Thus, as suggested by others,28 some of the findings that are used to place patients into the high clinical probability category appear to be nonspecific. If it is not possible to separate intermediate- from high-risk patients on the basis of clinical criteria, echocardiography may have a role as an additional diagnostic tool in these patients. As noted in our study, in most patients the additional information can be readily obtained by TTE alone.
A new set of diagnostic criteria has recently been formulated that categorizes findings into major and minor criteria analogous to the Jones criteria for rheumatic fever.28 It has been suggested that these new criteria improve the diagnostic accuracy for endocarditis by placing less weight on nonspecific findings (such as fever, vascular events, and immunologic phenomena). If these criteria were applied to our study population, the number of patients falsely classified as having a high probability by clinical grounds would decrease. This new paradigm, however, requires that echocardiography be performed in all patients with suspected endocarditis regardless of clinical probability. The results of our study indicate, however, that except in the case of prosthetic valves, patients with a low clinical probability of endocarditis do not benefit from echocardiography.
Our study did not address the issue of detecting the complications of endocarditis with echocardiography. Since complications occur in a minority of patients with endocarditis, confirmation with echocardiography can be reserved for those in whom there is a clinical probability of complications. It has also been argued that in patients suspected of having endocarditis, the absence of vegetations may preclude the use of a protracted full course of intravenous antibiotics.29 It is implied that routine use of TEE could therefore be cost saving in patients with suspected endocarditis. The results of our study pertaining to antibiotic use and duration do not support such a contention. Physicians tend to treat the clinical condition rather than the vegetations.
Even though we studied consecutive patients, selection bias is likely in our study for several reasons. First, ours is a tertiary care center, and patients seen at our institution do not necessarily reflect those seen in community hospitals. We serve a rural population, and the type of endocarditis seen at our institution is different from that seen in large metropolitan medical centers. For example, we saw right heart vegetations in only two patients, an incidence much lower than reported from city hospitals in which the incidence of intravenous drug abuse is higher. Nevertheless, unlike left heart vegetations, right heart vegetations are equally well visualized by TTE and TEE.30
Twelve patients had technically inadequate studies on TTE. Excluding these patients from comparative analysis is unlikely to have affected our results, since the demographic, clinical, and TTE findings of these patients were not significantly different from those of the rest of the patient cohort. Finally, the role of echocardiography may change within the same patient if the degree of clinical suspicion of endocarditis changes on the basis of new physical findings or laboratory evidence. Our study was not designed to address this issue.
Conclusions
From the results of our study, we recommend that
echocardiography be used with greater prudence in
patients with suspected endocarditis. It should not be used to make a
diagnosis of endocarditis in those with a low clinical probability of
the disease. In those with an intermediate or high clinical
probability, TTE should be the diagnostic procedure of
choice. The use of TEE for diagnosis of endocarditis should be reserved
only for patients who have prosthetic valves and in whom TTE is
either technically inadequate or indicates an intermediate probability
of endocarditis.
|
Acknowledgments |
|---|
This study was supported in part by a grant (R01-HL-48890) from the National Institutes of Health, Bethesda, Md (Dr Kaul). Dr Lindner is the recipient of a Fellowship Training Grant from the Virginia Affiliate of the American Heart Association, Glen Allen. Dr Kaul is an Established Investigator of the National Center of the American Heart Association, Dallas, Tex.
Received July 26, 1995; revision received August 28, 1995; accepted September 25, 1995.
|
References |
|---|
|
TopAbstractIntroductionMethods Results Discussion References |
|---|
1. Martin RP, Meltzer RS, Chia BL, Stinson EB, Rakowski H, Popp RL. Clinical utility of two-dimensional echocardiography in infective endocarditis. Am J Cardiol. 1980;46:379-385. [Medline] [Order article via Infotrieve]
2. Mintz GS, Kotler NM, Segal BL, Parry WR. Comparison of two-dimensional and M-mode echocardiography in the evaluation of patients with infective endocarditis. Am J Cardiol. 1979;43:738-744. [Medline] [Order article via Infotrieve]
3.
Wann LS, Hallam CC, Dillon JC, Weyman AE, Feigenbaum
H. Comparison of M-mode and cross-sectional
echocardiography in infective endocarditis.
Circulation. 1979;60:728-733.
4.
Stewart JA, Silimperi D, Harris P, Wise NK, Fraker
TD. Echocardiographic documentation of
vegetative lesions in infective endocarditis: clinical
implications. Circulation. 1980;61:374-380.
5. Jaffe WM, Morgan DE, Pearlman AS, Otto CM. Infective endocarditis, 1983-1988: echocardiographic findings and factors influencing morbidity and mortality. J Am Coll Cardiol. 1990;15:1227-1233. [Abstract]
6. Mugge A, Daniel WG, Frank G, Lichtlen P. Echocardiography in infective endocarditis: reassessment of prognostic implications of vegetation size determined by the transthoracic and the transesophageal approach. J Am Coll Cardiol. 1989;14:631-638. [Abstract]
7.
Stafford WJ, Petch J, Radford DG. Vegetations
in infective endocarditis: clinical relevance and diagnosis by
cross-sectional echocardiography.
Br Heart J. 1985;53:310-313.
8.
Erbel R, Rohmann S, Drexler M, Mohr-Kahaly S, Gerharz
CD, Iversen S, Oelert H, Meyer J. Improved
diagnostic value of echocardiography in
patients with infective endocarditis by
transoesophageal approach: a prospective
study. Eur Heart J. 1988;9:43-53.
9. Drexler M, Erbel R, Rohmann S, Mohr-Kahaly S, Meyer J. Diagnostic value of two-dimensional transoesophageal versus transthoracic echocardiography in patients with infective endocarditis. Eur Heart J. 1987;8(suppl J):303-306.
10. Daniel WG, Schroeder E, Nonnast-Daniel B, Lichtlen PR. Conventional and transesophageal echocardiography in the diagnosis of infective endocarditis. Eur Heart J. 1987;8(suppl J):287-292.
11.
Shapiro SM, Young E, De Guzman S, Ward J, Chung-Yin C,
Ginzton LE, Bayer AS. Transesophageal
echocardiography in diagnosis of infective
endocarditis. Chest. 1994;105:377-382.
12.
Taams MA, Gussenhoven EJ, Bos E, deJaegere P, Roelandt
JRTC, Sutherland GR, Bom N. Enhanced morphological diagnosis in
infective endocarditis by transoesophageal
echocardiography. Br Heart J. 1990;63:109-113.
13. Birmingham GD, Rahko PS, Ballantyne F. Improved detection of infective endocarditis with transesophageal echocardiography. Am Heart J. 1992;123:774-781. [Medline] [Order article via Infotrieve]
14.
Pederson WR, Walker M, Olson JD, Gobel F, Lange HW,
Daniel JA, Rogers J, Longe T, Kane M, Mooney MR, Goldenberg IF.
Value of transesophageal
echocardiography as an adjunct to
transthoracic echocardiography in
evaluation of native and prosthetic valve endocarditis.
Chest. 1991;100:351-356.
15. Daniel WG, Mugge A, Grote J, Hausmann D, Nikutta P, Laas J, Lichtlen PR, Martin RP. Comparison of transthoracic and transesophageal echocardiography for detection of abnormalities of prosthetic and bioprosthetic valves in the mitral and aortic positions. Am J Cardiol. 1993;71:210-215. [Medline] [Order article via Infotrieve]
16. Shively BK, Gurule FT, Roldan CA, Leggett JH, Schiller NB. Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis. J Am Coll Cardiol. 1991;18:391-397. [Abstract]
17. von Reyn CF, Levy BS, Arbeit RD, Freidland G, Crumpacker CS. Infective endocarditis: an analysis based on strict case definitions. Ann Intern Med. 1981;94:505-518.
18. Daniel WG, Mugge A, Martin RP, Lindert O, Hausmann D, Nonnast-Daniel B, Laas J, Lichtlen PR. Improvement in the diagnosis of abscesses associated with endocarditis by transesophageal echocardiography. N Engl J Med. 1991;324:795-800. [Abstract]
19.
Karalis DG, Bansal RC, Hauck AJ, Ross JJ, Applegate PM,
Jutzy KR, Mintz GS, Chandrasekaran K.
Transesophageal echocardiographic
recognition of subaortic complications in aortic valve
endocarditis. Circulation. 1992;86:353-362.
20. Khandheria BK, Freeman WK, Sinak LJ. Infective endocarditis: evaluation by transesophageal echocardiography. In: Freeman WK, Seward JB, Khandheria BK, Tajik AJ, eds. Transesophageal Echocardiography. Boston, Mass: Little, Brown & Co; 1994:307-337.
21. Mood AM, Graybill FA. Introduction to the Theory of Statistics. 2nd ed. New York, NY: McGraw Hill; 1963.
22. Libman E, Celler H. The etiology of subacute infective endocarditis. Am J Med Sci. 1910;140:516-526.
23. Hook E. Emanuel Libman and infective endocarditis: comments on the etiology of subacute infective endocarditis. Am J Med Sci. 1995;309:71-73. [Medline] [Order article via Infotrieve]
24. Sochowski RA, Kwan-Leung C. Implication of negative results on a monoplane transesophageal echocardiographic study in patients with suspected infective endocarditis. J Am Coll Cardiol. 1993;21:216-221. [Abstract]
25. Lowry RW, Zoghbi WA, Baker WB, Wray RA, Quinones MA. Clinical impact of transesophageal echocardiography in the diagnosis and management of infective endocarditis. Am J Cardiol. 1994;73:1089-1091. [Medline] [Order article via Infotrieve]
26.
Bayes R. An essay toward solving a problem in
the doctrine of chance. Philos Trans R Soc Lond. 1763;53:370-418.
27. Diamond G, Forrester J, Hirsch M, Staniloff HM, Vas R, Berman DS, Swan HJ. Application of conditional probability analysis to the clinical diagnosis of coronary artery disease. J Clin Invest. 1980;65:1210-1221.
28. Durack DT, Lukes AS, Bright DK. New criteria for diagnosis of infective endocarditis: utilization of specific echocardiographic findings. Am J Med. 1994;96:200-209. [Medline] [Order article via Infotrieve]
29. Khandheria BK. Suspected bacterial endocarditis: to TEE or not to TEE. J Am Coll Cardiol. 1993;21:222-224. [Medline] [Order article via Infotrieve]
30. San Roman JA, Vilacosta I, Zamorano JL, Almeria C, Sanchez-Harguinday L. Transesophageal echocardiography in right-sided endocarditis. J Am Coll Cardiol. 1993;21:1226-1230.[Abstract]
This article has been cited by other articles:
 |
|
 |
|
  T. E. Paterick, T. J. Paterick, R. A. Nishimura, and J. M. Steckelberg Complexity and Subtlety of Infective Endocarditis Mayo Clin. Proc., May 1, 2007; 82(5): 615 - 621. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. S. Finkelhor, G. Cater, A. Qureshi, D. Einstadter, M. T. Hecker, and G. Bosich Seasonal Diagnosis of Echocardiographically Demonstrated Endocarditis Chest, October 1, 2005; 128(4): 2588 - 2592. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. M. Baddour, W. R. Wilson, A. S. Bayer, V. G. Fowler Jr, A. F. Bolger, M. E. Levison, P. Ferrieri, M. A. Gerber, L. Y. Tani, M. H. Gewitz, et al. Infective Endocarditis: Diagnosis, Antimicrobial Therapy, and Management of Complications: A Statement for Healthcare Professionals From the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, and the Councils on Clinical Cardiology, Stroke, and Cardiovascular Surgery and Anesthesia, American Heart Association: Endorsed by the Infectious Diseases Society of America Circulation, June 14, 2005; 111(23): e394 - e434. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F Chirillo, A Pedrocco, A De Leo, A Bruni, O Totis, P Meneghetti, and P Stritoni Impact of harmonic imaging on transthoracic echocardiographic identification of infective endocarditis and its complications Heart, March 1, 2005; 91(3): 329 - 333. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Law, G. Honos, and T. Huynh Negative predictive value of multiplane transesophageal echocardiography in the diagnosis of infective endocarditis Eur J Echocardiogr, December 1, 2004; 5(6): 416 - 421. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. L. Geggel Conditions Leading to Pediatric Cardiology Consultation in a Tertiary Academic Hospital Pediatrics, October 1, 2004; 114(4): e409 - e417. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Sawni, K. Wright, and R. Ragothaman Hyperventilation and Chest Pain in an Adolescent Female: Index of Suspicion Clinical Pediatrics, September 1, 2004; 43(7): 663 - 666. [PDF]
|
|
|
|
|
|
C H Cabell and V G Fowler Jr Repeated echocardiography after the diagnosis of endocarditis: too much of a good thing? Heart, September 1, 2004; 90(9): 975 - 976. [Full Text] [PDF]
|
|
|
|
|
|
M L C Vieira, M Grinberg, P M A Pomerantzeff, J L Andrade, and A J Mansur Repeated echocardiographic examinations of patients with suspected infective endocarditis Heart, September 1, 2004; 90(9): 1020 - 1024. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P Robles Judicious use of transthoracic echocardiography in the diagnosis of infective endocarditis Heart, November 1, 2003; 89(11): 1283 - 1284. [Full Text] [PDF]
|
|
|
|
|
|
K Greaves, D Mou, A Patel, and D S Celermajer Clinical criteria and the appropriate use of transthoracic echocardiography for the exclusion of infective endocarditis Heart, March 1, 2003; 89(3): 273 - 275. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. Kuruppu, M. Corretti, P. Mackowiak, and M.-C. Roghmann Overuse of Transthoracic Echocardiography in the Diagnosis of Native Valve Endocarditis Arch Intern Med, August 12, 2002; 162(15): 1715 - 1720. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Mylonakis and S. B. Calderwood Infective Endocarditis in Adults N. Engl. J. Med., November 1, 2001; 345(18): 1318 - 1330. [Full Text] [PDF]
|
|
|
|
|
|
A. Perez-Vazquez, M. C. Farinas, J. D. Garcia-Palomo, J. M. Bernal, J. M. Revuelta, and J. Gonzalez-Macias Evaluation of the Duke Criteria in 93 Episodes of Prosthetic Valve Endocarditis: Could Sensitivity Be Improved? Arch Intern Med, April 24, 2000; 160(8): 1185 - 1191. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Aly, P. M. Simpson, and R. A. Humes The Role of Transthoracic Echocardiography in the Diagnosis of Infective Endocarditis in Children Arch Pediatr Adolesc Med, September 1, 1999; 153(9): 950 - 954. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Rozenman, D. Gilon, and S. Fuchs Where Did Good Old Clinical Diagnosis Go? N. Engl. J. Med., May 15, 1997; 336(20): 1435 - 1438. [Full Text] [PDF]
|
|
|
|
|
|
M. D. Cheitlin, J. S. Alpert, W. F. Armstrong, G. P. Aurigemma, G. A. Beller, F. Z. Bierman, T. W. Davidson, J. L. Davis, P. S. Douglas, L. D. Gillam, et al. ACC/AHA Guidelines for the Clinical Application of Echocardiography : A Report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines (Committee on Clinical Application of Echocardiography) Developed in Collaboration With the American Society of Echocardiography Circulation, March 18, 1997; 95(6): 1686 - 1744. [Full Text]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||