Echocardiography in bacterial endocarditis

Recognition and Treatment of Acute Aortic Regurgitation

Acute aortic regurgitation usually results from infective endocarditis, but is also caused by aortic dissection and trauma to the heart. Most of the left ventricular stroke volume is regurgitated back into the left ventricle; thus, the forward stroke volume to the body and the cardiac output may be severely compromised. An acute increase in left ventricular end-diastolic volume results in a marked increase in left ventricular end-diastolic pressure, and the mitral valve usually closes prematurely. Compensatory tachycardia is the rule and helps to shorten diastole; thus, the time available for aortic regurgitation to occur is reduced, and the cardiac output is often maintained.

On physical examination, there is tachycardia; the peripheral arterial pulse shows a rapid rise, but the systolic pressure is normal; the diastolic pressure is normal or even reduced; and the pulse pressure is often normal. The electrocardiogram (ECG) may be normal except for sinus tachycardia and often for nonspecific ST-T changes. The chest roentgenogram usually shows signs of pulmonary venous hypertension or even pulmonary edema. Echocardiography may show vegetations on the aortic valve, prolapse of an aortic leaflet into the left ventricle, and premature mitral valve closure. Doppler echocardiography is useful in detecting the presence of aortic regurgitation.

In cases of infective endocarditis, the appropriate antibiotic therapy must be given. Aortic regurgitation due to dissection of the aorta is usually an indication for surgery. In patients with severe aortic regurgitation, available medical therapy includes digitalis, diuretics, and vasodilators. When patients respond dramatically to the use of digitalis, diuretics, and arterial dilators, surgical therapy can be delayed until heart failure and infection are controlled and the patient is more stable. If the patient does not respond immediately and dramatically to therapy, then valve replacement should not be delayed, even if the infection is uncontrolled or the patient has had little antibiotic therapy.

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.

Single and multiple beam echocardiography in aortic valve endocarditis. Report of three cases

Three patients with aortic valve endocarditis were studied. The single beam M-mode echocardiographic findings comprised the appearance in diastole of a cluster of shaggy echoes at the aortic valve in all three patients. Mitral flutter was seen in two patients and premature closure of the mitral valve in one patient. At multiple beam two-dimensional echocardiography, the echo cluster could in all three patients be seen to move perpendicular to the sound beams, ascending into the aorta in systole and descending in diastole. At valve replacement, vegetations were found that explained the abnormal echo cluster. The multiple beam echocardiography facilitated the interpretation of the single beam findings and increased the confidence therein. By applying the non-invasive modality of echocardiography in these patients with their high risk of embolism, cardiac catheterization may possibly be avoided.

Antithrombotic Therapy in Valvular Heart Disease—Native and Prosthetic

This chapter about antithrombotic therapy in native and prosthetic valvular heart disease is part of the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy: Evidence Based Guidelines. Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs. Grade 2 suggests that individual patients' values may lead to different choices (for a full understanding of the grading see Guyatt et al, CHEST 2004; 126:179S-187S). Among the key recommendations in this chapter are the following: For patients with rheumatic mitral valve disease and atrial fibrillation (AF), or a history of previous systemic embolism, we recommend long-term oral anticoagulant (OAC) therapy (target international normalized ratio [INR], 2.5; range, 2.0 to 3.0) [Grade 1C+]. For patients with rheumatic mitral valve disease with AF or a history of systemic embolism who suffer systemic embolism while receiving OACs at a therapeutic INR, we recommend adding aspirin, 75 to 100 mg/d (Grade 1C). For those patients unable to take aspirin, we recommend adding dipyridamole, 400 mg/d, or clopidogrel (Grade 1C). In people with mitral valve prolapse (MVP) without history of systemic embolism, unexplained transient ischemic attacks (TIAs), or AF, we recommended against any antithrombotic therapy (Grade 1C). In patients with MVP and documented but unexplained TIAs, we recommend long-term aspirin therapy, 50 to 162 mg/d (Grade 1A). For all patients with mechanical prosthetic heart valves, we recommend vitamin K antagonists (Grade 1C+). For patients with a St. Jude Medical (St. Paul, MN) bileaflet valve in the aortic position, we recommend a target INR of 2.5 (range, 2.0 to 3.0) [Grade 1A]. For patients with tilting disk valves and bileaflet mechanical valves in the mitral position, we recommend a target INR of 3.0 (range, 2.5 to 3.5) [Grade 1C+]. For patients with caged ball or caged disk valves, we suggest a target INR of 3.0 (range, 2.5 to 3.5) in combination with aspirin, 75 to 100 mg/d (Grade 2A). For patients with bioprosthetic valves, we recommend vitamin K antagonists with a target INR of 2.5 (range, 2.0 to 3.0) for the first 3 months after valve insertion in the mitral position (Grade 1C+) and in the aortic position (Grade 2C). For patients with bioprosthetic valves who are in sinus rhythm and do not have AF, we recommend long-term (> 3 months) therapy with aspirin, 75 to 100 mg/d (Grade 1C+).

The relative roles of transthoracic compared with transesophageal echocardiography in children with suspected infective endocarditis

OBJECTIVES

The study evaluated the additional benefit of transesophageal echocardiography (TEE) versus transthoracic echocardiography (TTE) in pediatric cases with suspected bacterial endocarditis.

BACKGROUND

In adult patients, TTE has a lower sensitivity and specificity than TEE for the detection of vegetations or aortic root abscess formation. Few data are available about the relative benefits of TEE over TTE in the pediatric age group.

METHODS

Patients were included if they had positive blood cultures for typical microorganisms and had a TTE and TEE within 14 days of each other. The patients had to meet the Duke criteria for a positive diagnosis of bacterial endocarditis. The TTE and TEE data were analyzed using the McNemar test for the significance of change.

RESULTS

Twenty-one patients fulfilled the criteria, at a median age of 9.5 years. Congenital heart disease was present in 13 patients; 4 patients were previously healthy and 4 patients had other medical problems. Nine patients had surgical confirmation of bacterial endocarditis. Fifteen patients had a positive cardiac finding, with 12 vegetations, 2 vegetations plus aortic root abscess, and 1 isolated abscess. There was excellent agreement between TTE and TEE in those cases with positive cardiac findings, with a p = 0.32, kappa 0.89. Using positive TEE cardiac findings as the gold standard, the sensitivity for TTE was 86% for all 15 events and 93% for the detection of a vegetation.

CONCLUSIONS

In pediatric cases, TTE has a high degree of sensitivity for the detection of supportive evidence of endocarditis, and TEE should be reserved for patients with a poor transthoracic window.

Sensitivity of transthoracic versus transesophageal echocardiography for the detection of native valve vegetations in the modern era

BACKGROUND

Thirteen years ago, transthoracic echocardiography (TTE) was found to be less sensitive than transesophageal echocardiography (TEE) for native valve vegetations. Since then, harmonic imaging and other advances have improved TTE. How this affects the sensitivity of TTE is unknown.

METHODS

Fifty patients with echocardiography-diagnosed endocarditis had TTE and TEE examinations on high-end machines. These were matched for date of study with 50 patients who had TTE and TEE examinations that were negative for vegetations.

RESULTS

A total of 51 vegetations were seen on TEE. The sensitivity of TTE for vegetations was only 55% (aortic 50% [12/24]; mitral 62% [16/26]; tricuspid 0% [0/1]). Anatomic valvular abnormalities did not alter the sensitivity of TTE (P =.42 for mitral; P =.97 for aortic valves). However, larger vegetations were more likely to be found by TTE.

CONCLUSION

Despite advances in imaging during 12 years, TTE is still insensitive compared with TEE for the detection of native valve vegetations, and fails to demonstrate nearly half of them.

Value of echocardiographic findings in predicting cardiovascular complications in infective endocarditis

Echocardiography allows the detection of vegetations and estimation of valvular dysfunction in patients with infective endocarditis. The value of echocardiographic findings in predicting cardiac and other vascular complications in infective endocarditis is not well understood. Identification of high-risk patients and early surgery may improve their prognosis. The authors reviewed echocardiographic findings and related them to the development of congestive heart failure, systemic embolism, and the need for surgery or the risk of death without surgery in patients with infective endocarditis. There were 125 episodes of endocarditis in 114 patients (84 episodes [67%] in men) with a mean age +/- standard deviation of 37 +/- 7 years. Vegetations were detected by echocardiography on at least 1 valve in 87 episodes (70%); on the mitral valve in 36 episodes (29%); on the aortic valve in 21 episodes (17%); and on the tricuspid valve in 45 episodes (36%). Severe aortic regurgitation was present in 9 episodes (7%) and severe mitral regurgitation in 4 instances (3%). In 12 of 21 episodes (57%) of vegetations on the aortic valve compared with 15 of 104 patients (14%) without vegetations on the aortic valve (p < 0.001), and in 8 of 9 instances (89%) of severe aortic regurgitation compared with 19 of 116 episodes (16%) without severe aortic regurgitation (p<0.00001), the patients developed congestive heart failure. In 18 of 55 episodes (33%) of vegetations on the aortic/mitral valve compared with 17 of 70 episodes (25%) without vegetations on the aortic valve/mitral valve (p = NS), the patients developed systemic embolism. In 13 of 21 episodes (62%) of vegetations on the aortic valve compared with 19 of 104 episodes (19%) without vegetations on the aortic valve (p < 0.001), and in 8 of 9 episodes (89%) of severe aortic regurgitation compared with 24 of 116 episodes (21%) without severe aortic regurgitation (p < 0.00001), the patients either had surgery or died without surgery. Echocardiographic findings do not reliably predict the risk of systemic embolism in patients with infective endocarditis. Vegetations on the aortic valve and severe aortic regurgitation detected by echocardiography predict a high risk of developing congestive heart failure, and for the combined outcome of requiring surgery, or dying without surgery in infective endocarditis. Early surgery may improve the outlook for survival of these patients.

Echocardiography predicts embolic events in infective endocarditis

OBJECTIVES

The aim of our study was to assess the value of transesophageal echocardiography (TEE) in predicting embolic events (EEs) in a large group of patients with definite endocarditis according to the Duke criteria, including silent embolism.

BACKGROUND

The value of echocardiography in predicting embolism in patients with endocarditis remains controversial. Some studies reported an increased risk of embolism in patients with large and mobile vegetations, whereas other studies failed to demonstrate such a relationship.

METHODS

Multiplane transesophageal echocardiograms of 178 consecutive patients with definite infective endocarditis (IE) were analyzed. The incidence of embolism was compared with the echocardiographic characteristics (localization, size and mobility) of the vegetations. To detect silent embolism, cerebral and thoraco-abdominal scans were performed in 95% of patients.

RESULTS

Among 178 patients, 66 (37%) had one or more EEs. There was no difference between patients with and without embolism in terms of age, gender and left valve involved. On univariate analysis, Staphylococcus infection, right-side valve endocarditis and vegetation length and mobility were significantly related to EEs. A significant higher incidence of embolism was present in patients with vegetation length >10 mm (60%, p < 0.001) and in patients with mobile vegetations (62%, p < 0.001). Embolism was particularly frequent among 30 patients with both severely mobile and large vegetations (> 15 mm) (83%, p < 0.001). On multivariate analysis, the only predictors of embolism were vegetation length (p = 0.03) and mobility (p = 0.01).

CONCLUSIONS

Our study shows that the presence of vegetations on TEE is predictive of embolism and that the morphologic characteristics of vegetations are helpful in predicting EEs in both mitral and aortic valve IE. It also suggests that early operation may be recommended in patients with vegetations > 15 mm and high mobility, irrespective of the degree of valve destruction, heart failure and response to antibiotic therapy.

Native valve infective endocarditis: what is the optimal timing for surgery?

IE remains a dreaded disease masquerading under a myriad of presentations in an evolving epidemiological environment. In our continuing endeavor against this deadly disease, echocardiography has evolved into an indispensable diagnostic tool to define structural complications and guide therapy. Timing of surgical intervention for IE remains a subject of intense debate and depends on the cardiac and systemic complications of the infection, the virulence of the organism, and the responsiveness to medical therapy. A judicious agreement among cardiologist, cardiovascular surgeon, and infectious disease specialist should define whether surgical intervention is warranted and, if so, the optimal timing. Further optimization of guidelines will help in the diagnosis and treatment of endocarditis but will never be a substitute for sound judgment and experience.

Active vegetations can be differentiated from chronic vegetations by visual inspection of standardized two-dimensional echocardiograms

The ability to differentiate active from chronic valvular vegetations (VEGs) by digital image processing and by visual observation was evaluated in 18 patients with a clinical diagnosis of infective endocarditis (IE). Two-dimensional echocardiographic (2-DE) examinations were performed on all patients at diagnosis and after a mean period of 52 days. Two comparable images (active and chronic) from the same patient and in the same phase of the cardiac cycle were digitized, magnified, and displayed on a high resolution monitor. The mean pixel intensity (MPI) was 72+/-14 in the active stage and 143 +/-23 in the chronic stage (P<0.0001). The VEG size was 0.64+/- 0.15 cm(2) in the active stage and decreased to 0.46+/-0.17 cm(2) in the chronic stage (P<0.001). Two experienced echocardiographers, who were blinded to the age of the VEGs, identified each echocardiographic image as active or chronic based on visual observation of density of the VEGs. The VEGs were correctly identified as active or chronic in 17 out of the 18 patients. In summary, although digital image processing of 2-DE may be useful, the density of VEGs assessed by visual inspection will help differentiate between active and chronic VEGs of IE. The standardization procedure at the time of the initial study and use of identical gain settings in subsequent studies are key factors in making this distinction.

Role of transthoracic and transesophageal echocardiography in predicting embolic events in patients with active infective endocarditis involving native cardiac valves

Some studies describe an increased risk for emboli in infective endocarditis patients with large (>10 mm) and mobile vegetations. Other studies fail to demonstrate the above relation. Most studies have been performed using transthoracic echocardiography or with a monoplane transesophageal approach. The present study examines whether distinctive characteristics of vegetative lesions detected by transthoracic and multiplane transesophageal echocardiography are predictive of embolic risk. We reviewed both transthoracic and transesophageal echocardiograms of 57 patients with diagnosis of acute infective endocarditis and no documented or suspected previous embolic events. We evaluated site, length, width, mobility, and echodensity of vegetations. Twenty-five patients (44%) had embolic events. No statistical differences in age, sex distribution, location of endocarditis, or offending pathogens between embolic (n = 25) and nonembolic (n = 32) patients were found. There were no differences in any of the echo characteristics of vegetations detected by transthoracic and transesophageal approach in embolic and nonembolic groups. Thus, transthoracic and transesophageal characteristics of vegetations are not helpful in defining embolic risk in patients with infective endocarditis.

Effect of antibiotic treatment on vegetation size and complication rate in infective endocarditis

BACKGROUND

Infective endocarditis is associated with significant morbidity and mortality, with valvular destruction, and with congestive heart failure. Embolic events are more common in patients with echocardiographically discernible vegetations, especially when vegetations are > 10 mm in diameter.

HYPOTHESIS

The objective of the study was to follow vegetation morphology during native valve endocarditis, to compare it with the clinical course and antibiotic treatment chosen, and to evaluate whether the impact on vegetation size and complication rate of antibiotic regimens differed in patients with positive and negative blood cultures.

METHODS

The effect of different antibiotic regimes on vegetation size monitored by using transesophageal echocardiography was evaluated in 183 patients with echocardiographic evidence of infective endocarditis. A total of 223 vegetations attached to the aortic or mitral valves were detected using the transesophageal approach. The patients were followed for a mean of 76 weeks and underwent a minimum of two consecutive transesophageal echocardiographic examinations.

RESULTS

Treatment with different kinds of antibiotics corresponded with significant differences in vegetation size; vancomycin-associated treatment was related to a 45% reduction, ampicillin to a 19% reduction, penicillin to a 5% reduction, penicillase-resistant drugs to a 15% increase, and cephalosporin to a 40% increase in vegetation size. Multivariate analysis showed that penicillin, cephalosporin, and penicillase-resistant drug treatments were associated with an increased embolic risk, vancomycin treatment with abscess formation, and cephalosporin medication with increased mortality. Plotting changes in vegetation size against the incidence of embolism and mortality, linear regression analysis suggested a 40-50% reduction in vegetation size, thereby greatly reducing the risk of embolism and mortality.

CONCLUSION

Our study shows that different antibiotics have different effects on vegetation size. The highest complication rate was observed when vegetations significantly increased in size during antibiotic treatment. Especially in culture-negative patients, monitoring vegetation size by means of transesophageal echocardiography may prove to be useful for estimating the efficacy of antibiotic treatment.

Role of transthoracic and transesophageal echocardiography in diagnosis and management of infective endocarditis

Echocardiography has become a mainstay in the diagnosis of endocarditis. Vegetations were first visualized noninvasively beginning with M-mode echocardiography in the mid-1970s. The evolution of echocardiography, to include first two-dimensional imaging and then Doppler imaging in the 1980s, established echocardiography as the noninvasive test of choice to evaluate for the presence of vegetations as well as for their sequelae. Most recently, the addition of transesophageal echocardiography has expanded the role and yield of echocardiography in diagnosing endocarditis as well as in guiding management.

A negative transthoracic echocardiogram obviates the need for transesophageal echocardiography in patients with suspected native valve active infective endocarditis

We studied 134 patients with suspected native valve infective endocarditis who underwent transthoracic and transesophageal echocardiography. Our data suggest that in patients without prosthetic valves who have a technically adequate negative transthoracic echocardiogram, transesophageal echocardiography is unlikely to be of incremental benefit in diagnosing endocarditis.

Early identification of patients with native valve infectious endocarditis at risk for major complications by initial clinical presentation and baseline echocardiography

Early identification of a high risk patient subgroup with infective endocarditis which develops a major complication (emboli, congestive heart failure, surgery for valve replacement, or death) during hospitalization would reduce morbidity, mortality and cost. Thus, for 74 patients with native valve infective endocarditis with documented vegetation by transthoracic two-dimensional echocardiogram, we reviewed 67 variables: history (15), physical examination (9), hematology/miscellaneous (7), chest X-ray (2), electrocardiogram (4), transthoracic two-dimensional echocardiograms (15) and hospital course (15). There were 48 men and 26 women, ages 45 +/- 19 years: 35 intravenous drug abusers and 39 non-users. There were 32 mitral, 21 tricuspid, 20 aortic, and 1 pulmonic valve vegetations; mean vegetation size was 1.4 +/- 0.9 cm2. Over the course of their hospitalization, 14 patients died (19%), 27 developed congestive heart failure (36%), 27 had systemic emboli (36%), and 22 required surgery (30%). The incidence of complications (death, heart failure or embolic events) did not differ between the drug abusers and non-users. Initial complaint of dyspnea on admission predicted the subsequent development of heart failure (P < 0.001), and a pre-admission embolus predicted a second in-hospital embolus (P < 0.001). Left atrial size, ventricular systolic or diastolic dimension did not effect prognosis. Importantly, a vegetation > 1.8 cm2 was 100% specific but only 30% sensitive for predicting the development of a complication. Vegetation mobility, shape, and number of cusps involved were not predictive. However, aortic valve vegetations had significantly more complications than those on the mitral valve (P < 0.03). By discriminant function analysis, 87% of major complications were predicted with the patient profile of having aortic valve vegetation, dyspnea on admission, prolonged preadmission fever, and no history of drug abuse; 75% of patients who developed heart failure were predicted by their having aortic valve vegetation, dyspnea, hypotension (systolic < 90 mm Hg), and no history of drug abuse; and 77% of patients requiring surgery were predicted by their having larger vegetation size, rales, and leftward shift of white blood cells. Thus, in native valve bacterial endocarditis with transthoracic echocardiographic documented vegetations, non-drug abusers with aortic vegetations, preadmission prolonged fevers, dyspnea, emboli and larger sized vegetations are at high risk for developing a major complication during their hospitalization.

Echocardiographic assessment of vegetations in patients with infective endocarditis: prognostic implications

Today, echocardiography is the most important technique next to clinical findings and blood cultures in the diagnosis of infective endocarditis. The sensitivity of echocardiography, particularly the transesophageal approach, for detection of vegetations and endocarditis related valvular destructions is high. In addition, echocardiographic findings may have some prognostic implications. The size and mobility of vegetations stratifies endocarditis patients into a high risk group for arterial embolism. In particular, mobile vegetations attached to the mitral valve with a maximal diameter > 10 mm may be prone to embolic events. Furthermore, increase in size of vegetations during antimicrobial treatment may identify patients with no, or at least a prolonged, healing process. Also, a lack of increase in the echo density of vegetations under adequate antibiotic treatment may indicate a poor healing process and may necessitate more aggressive management. The demonstration of paravalvular abscesses by echocardiography, particularly by transesophageal echocardiography, identifies a subgroup of patients who will need urgent cardiac surgery before widespread tissue destruction has occurred.

Value of transthoracic echocardiography in predicting embolic events in active infective endocarditis. Duke Endocarditis Service

The purpose of this study was twofold: (1) to determine interobserver variability of echocardiographic characteristics of vegetations in patients with infective endocarditis, and (2) to assess the value of these vegetation characteristics in predicting embolic events. Although echocardiography contributes to the diagnosis of patients with infective endocarditis, its prognostic role in predicting embolic events is controversial. The echocardiograms of 41 patients with infective endocarditis were independently reviewed by 4 echocardiographers blinded to the clinical data. If a vegetation was present, the following characteristics were analyzed: involved site, size, mobility, shape, and pedunculated or sessile attachment. Each echocardiographer also made a "gestalt" estimate of embolic risk based on these vegetation characteristics. Interobserver agreement on vegetation characteristics and their relation to embolic events was then determined using kappa statistics and logistic regression analysis. Interobserver agreement was 98% with regard to echocardiographic vegetation presence and 97% with regard to the involved site. Of the 30 patients in whom vegetations were observed, complete observer agreement was achieved with regard to size in 22 (73%), mobility in 17 (57%), shape in 11 (37%), and attachment in 12 (40%). Vegetations with a maximal diameter of > 10 mm were associated with a 50% incidence of embolic events, compared with a 42% incidence of emboli in patients with vegetations measuring < or = 10 mm. Interobserver variability was great with respect to vegetation shape, mobility, and attachment characteristics. Echocardiographic vegetation characteristics were not helpful in defining the risk of embolic complications in patients with endocarditis.

Application of transthoracic and transesophageal echocardiography in the diagnosis and management of infective endocarditis

Infective endocarditis continues to be a cause of significant cardiac morbidity and mortality. To improve the prognosis of patients with this disorder, early diagnosis is crucial but difficult to establish on the basis of clinical parameters alone. Echocardiography, both transthoracic and transesophageal techniques, has a major role in the detection of vegetations that are the hallmark of endocarditis. Valvular and perivalvular complications can also be well assessed by echocardiography. With the improved resolution provided by recent technologic advances in echocardiography, vegetations can be reliably detected in most patients with endocarditis. We propose that present diagnostic criteria for endocarditis be revised to include echocardiographic findings as a major parameter in the diagnosis. Finally, a diagnostic approach incorporating transthoracic and transesophageal echocardiography in these patients will be discussed taking into consideration the different degrees of clinical suspicion for the existence of the disease.

Transesophageal echocardiography in right-sided endocarditis

OBJECTIVES

Our aim was to determine the diagnostic value of transesophageal echocardiography in right-sided endocarditis.

BACKGROUND

Recent studies have demonstrated that transesophageal echocardiography is superior to transthoracic echocardiography in the detection of vegetations associated with left-sided endocarditis. Its diagnostic value in right-sided endocarditis has not been established.

METHODS

Transthoracic and transesophageal echocardiography were prospectively performed in 48 patients who met specific criteria for the suspicion of right-sided endocarditis. All were intravenous drug abusers.

RESULTS

Vegetations were found in 22 of 48 patients by both transthoracic and transesophageal echocardiography. The vegetations were more precisely characterized by transesophageal echocardiography in 14 (63%) of 22 patients. In the remaining 26 patients, no vegetations were found by either transthoracic or transesophageal echocardiography. No statistically significant differences were found between the two techniques in the assessment of tricuspid regurgitation, which was detected in 21 (44%) of 48 patients.

CONCLUSIONS

We conclude that transesophageal echocardiography does not improve the diagnostic accuracy of transthoracic echocardiography in the detection of vegetations associated with right-sided endocarditis in intravenous drug abusers. Transesophageal echocardiography may not be indicated as a routine procedure in patients suspected of having right-sided endocarditis.

Implication of negative results on a monoplane transesophageal echocardiographic study in patients with suspected infective endocarditis

OBJECTIVES

This study was conducted to determine the implications of negative findings on a transesophageal echocardiographic study in which neither a vegetation nor an abscess is identified in patients with clinically suspected infective endocarditis.

BACKGROUND

Echocardiography is the procedure of choice for evaluating suspected infective endocarditis in patients. Transesophageal echocardiography has been shown to be superior to transthoracic imaging. Although the importance of positive results or a diagnostic study is known, the significance of negative findings on a transesophageal study is not clear.

METHODS

All transesophageal echocardiographic studies performed over a 2-year period for suspected infective endocarditis were reviewed and the clinical course of patients with an initially negative study result was assessed to determine their final diagnosis.

RESULTS

Of the 105 patients identified, 65 had a negative transesophageal study result. In the majority of this group (56 of 65), an alternate diagnosis was made or there was no infective endocarditis on follow-up examination, or both. Of the remaining nine patients, four were treated for endocarditis without a definite diagnosis and five had infective endocarditis proved by either repeat transesophageal study (n = 3), pathologic findings (n = 1) or a diagnostic clinical course (n = 1). Gram-positive bacteremia and the presence of a prosthetic valve in the aortic position tended to be more common in the latter group.

CONCLUSIONS

A negative transesophageal study result reduces the likelihood that endocarditis is present. Repeat examination, however, should be considered in high risk patients, such as those with prosthetic valves or unexplained bacteremia, to avoid a missed diagnosis.

Infective endocarditis in children: profile in a developing country

With the object of studying the profile of infective endocarditis in Indian children younger than 16 years of age, a retrospective study of 37 patients with infective endocarditis admitted to this hospital between January 1984 and December 1990 was carried out. There were 26 boys and 11 girls (aged 2-16 years (mean (SD) 10.3 (3.8)). Eighteen (48.6%) patients had underlying congenital heart disease, 13 (35.1%) had associated rheumatic heart disease whilst the remaining six had no pre-existing heart disease. All six patients with a normal heart and infective endocarditis had preceding extra-cardiac bacterial illnesses (epididymitis and orchitis in one, pneumonia in five). Blood cultures were positive in only 16 (43.2%): Staphylococcus aureus was grown in nine, Streptococcus viridans in six and Candida albicans in one. Sixteen (43.2%) of the 37 patients died owing to worsening cardiovascular haemodynamics, uncontrolled septicaemia and our inability to offer emergency surgery. The profile of infective endocarditis in developing countries is different from that in Europe and the United States of America, and the disease carries a very high mortality.

Spontaneous echo contrast imaging in infective endocarditis: a predictor of complications?

Infective endocarditis is associated with significant morbidity and mortality. Valvular destruction and congestive heart failure are more common in patients with echocardiographically detectable vegetations. In addition, spontaneous platelet aggregation is increased when vegetations are present on cardiac valves. The aim of the study was to assess the prognostic value of spontaneous echo contrast (SEC) imaging, as SEC is supposed to reflect red blood cell aggregates stimulated by platelet activity. We studied 293 patients with clinical signs of infective endocarditis. Vegetations, attached to the aortic or mitral valve, were found in 130 patients (44.4%) who were followed for a mean period of 12 months. In 34 of these 130 patients (26.2%) SEC was imaged during the initial transesophageal echocardiographic examination. In these patients SEC indicated a prolonged healing of infective endocarditis with a specificity of 91.2%, a sensitivity of 77.3%, a positive accuracy of 77.3%, a negative accuracy of 74.3%. Multivariate analysis revealed that SEC is a risk factor for valve replacement (p less than 0.001) and for embolic events (p less than 0.001), less for mortality (p less than 0.01), and lowest for abscess formation (p less than 0.05). The dose of ADP to induce half-maximal platelet aggregation was significantly lower in patients with SEC (0.71 +/- 0.15 microliters) than without SEC (1.05 +/- 0.12 microliters; p less than 0.05), implying an increased spontaneous platelet aggregation in the presence of SEC. Our data provide evidence that systemically activated coagulation plays an important role in infective endocarditis. SEC, the echocardiographic implication of an increased platelet aggregation, predicts complications such as thromboembolic events and the need for surgery and is closely related to the prolonged healing period of infective endocarditis. In addition to demonstrating vegetations, transesophageal echocardiography provides information helpful in assigning patients to a high-risk subgroup. Transesophageal echocardiography may play an important role in assessing the clinical outcome of these patients.

Cardiac evaluation

Over the past decade there has been a dramatic, rapid development of new imaging modalities used in the evaluation of the cardiac patient. These newer techniques are frequently complex and specialized in their application and interpretation. Nonetheless, the prevalence of cardiac disease in the United States, and the wide application of these diagnostic tests, mandate that the well-rounded clinician has a basic understanding of the utility of these diagnostic modalities. Unfortunately, the burgeoning field of cardiac imaging seems at times to overshadow our most important basic diagnostic tools, namely, the history, physical exam, chest radiograph, and electrocardiogram (ECG). This review will attempt to impart a basic understanding of the newer cardiac diagnostic tests and their utility in various disease states. Emphasis on the importance of the basic clinical exam and the precise integration of specific diagnostic tests into the cardiac evaluation will be emphasized. The article will deliver a basic review of exercise treadmill testing, echocardiography, radionuclide imaging techniques, magnetic resonance imaging, and cardiac catheterization. It is hoped that this review will impart to the noncardiologist clinician a basic understanding of the cardiovascular diagnostic techniques so that an accurate, precise, cost-effective, efficient diagnostic plan for the patient with cardiovascular disease can be developed and applied.

Echocardiographic assessment of patients with infectious endocarditis: prediction of risk for complications

To enhance the echocardiographic identification of high risk lesions in patients with infectious endocarditis, the medical records and two-dimensional echocardiograms of 204 patients with this condition were analyzed. The occurrence of specific clinical complications was recorded and vegetations were assessed with respect to predetermined morphologic characteristics. The overall complication rates were roughly equivalent for patients with mitral (53%), aortic (62%), tricuspid (77%) and prosthetic valve (61%) vegetations, as well as for those with nonspecific valvular changes but no discrete vegetations (57%), although the distribution of specific complications varied considerably among these groups. There were significantly fewer complications in patients without discernible valvular abnormalities (27%). In native left-sided valve endocarditis, vegetation size, extent, mobility and consistency were all found to be significant univariate predictors of complications. In multivariate analysis, vegetation size, extent and mobility emerged as optimal predictors and an echocardiographic score based on these factors predicted the occurrence of complications with 70% sensitivity and 92% specificity in mitral valve endocarditis and with 76% sensitivity and 62% specificity in aortic valve endocarditis.

Group A streptococcus endocarditis: report of five cases and review of literature

Group A streptococcus is an uncommon cause of infective endocarditis. We report five probable cases during a 10-year period (1980-1989) from a 750-bed community-teaching hospital. None of the patients were drug abusers. Group A streptococcus is the cause of infective endocarditis in between 0 and 5% cases in reported series. Since the introduction of penicillin 69 cases of group A streptococcus endocarditis have been reported in the literature. Clinical details of 14 patients, none of whom were drug abusers, are available. Included are our five cases. Eight patients had no underlying valve lesions. The overall mortality was 21% but only 15% for patients treated approximately. Among the 25 reported IV drugs abusers with group A streptococcus endocarditis and known valve involvement, right-sided heart valves were involved in 19 and left sided in six. The overall mortality was 9%.

Prediction of rapid versus prolonged healing of infective endocarditis by monitoring vegetation size

The diagnostic value of transesophageal echocardiography in monitoring the clinical course has been evaluated in 83 patients with echocardiographic evidence of infective endocarditis. A total of 103 vegetations attached to the aortic or mitral valves were detected by use of the transesophageal approach. The patients were monitored for a mean of 74 weeks and underwent a minimum of two consecutive transesophageal echocardiographic examinations. Group A included patients with increasing or remaining constant size of vegetation (8.2 +/- 1.5 to 11.2 mm, p less than 0.05) during 4 to 8 weeks of antimicrobial therapy, whereas group B was formed by patients with decreasing vegetation size (8.3 +/- 0.8 to 4.9 +/- 0.8 mm, p less than 0.05). The incidences of complications after diagnosis and onset of therapy was higher in group A than in group B: valve replacement (45% versus 2%, p less than 0.05), embolic events (45% versus 17%, p less than 0.05), perivalvular abscess formation (13% versus 2%, p less than 0.05), and mortality (10% versus 0%, respectively, p less than 0.05). Staphylococcus aureus was the most frequent organism isolated in group A (44% versus 11% in B, p less than 0.05) and Streptococcus viridans in group B (33% versus 18% in A, p less than 0.05). Blood cultures were negative in nearly 50% of the patients in each group. There was no difference in the incidences of complications in patients with positive or negative blood cultures. We conclude that an increase in vegetation size during antibiotic therapy predicts a prolonged healing phase of infective endocarditis. This prolonged healing period is associated with a significantly increased risk of complications, independent of blood culture results. Monitoring vegetation size contributes important information concerning prognosis and stage of risk, and it aids in the choice of patient management in infective endocarditis. Because embolic events after diagnosis and onset of treatment are less frequent in rapid-healing endocarditis, surgery cannot be recommended to prevent further events taking into account the high risk of surgery.

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.

The role of two-dimensional echocardiology in the diagnosis of infective endocarditis [corrected]

Two-dimensional echocardiography has had a significant impact on and is considered the technique of choice for the diagnosis and management of infective endocarditis. Over a thirty-six month period, 106 patients were evaluated by echocardiography for the possibility of endocarditis. The diagnosis of endocarditis was determined by strict clinical and laboratory criteria. All clinical histories, blood cultures, echocardiograms, and autopsy results were reviewed. Five echocardiograms were technically inadequate, resulting in a study population of 101 patients. The age of the patients ranged from forty-five days to eighty-eight years (mean fifty-seven years). The clinical manifestations of endocarditis included fever (83%), chills (60%), congestive heart failure (25%), and splenomegaly (18%). Twelve patients had preexisting valvular or congenital heart disease. Gram-positive cocci were the most common microorganisms. Complications included mitral regurgitation, subarachnoid hemorrhage, renal infarction, stroke, and a pulmonary embolus. The patients were divided into two groups: Group I consisted of 36 patients with definite vegetations by echocardiography, and Group II had 65 patients with no vegetations. In Group I, acute infective endocarditis was present in 35 patients, whereas only 4 patients had endocarditis in Group II. The sensitivity of two-dimensional echocardiography for detecting endocarditis was 90%. The specificity was 98%. The predictive accuracy for a positive test was 97%, and the predictive accuracy for a negative test was 94%. Thus, two-dimensional echocardiography appears to have a high sensitivity, specificity, and predictive value in the evaluation of patients with suspected endocarditis.

Improvement in the diagnosis of abscesses associated with endocarditis by transesophageal echocardiography

BACKGROUND

Echocardiography is recognized as the method of choice for the noninvasive detection of valvular vegetations in patients with infective endocarditis, with transesophageal echocardiography being more accurate than transthoracic echocardiography. The diagnosis of associated abscesses by transthoracic echocardiography is difficult or even impossible in many cases, however, and it is not known whether transesophageal echocardiography is any better.

METHODS

To determine the value of transesophageal echocardiography in the detection of abscesses associated with endocarditis, we studied prospectively by two-dimensional transthoracic and transesophageal echocardiography 118 consecutive patients with infective endocarditis of 137 native or prosthetic valves that was documented during surgery or at autopsy.

RESULTS

During surgery or at autopsy, 44 patients (37.3 percent) had a total of 46 definite regions of abscess. Abscesses were more frequent in aortic-valve endocarditis than in infections of other valves, and the infecting organism was more often staphylococcus (52.3 percent of cases) in patients with abscesses than in those without abscesses (16.2 percent). The hospital mortality rate was 22.7 percent in patients with abscesses, as compared with 13.5 percent in patients without abscesses. Whereas transthoracic echocardiography identified only 13 of the 46 areas of abscess, the transesophageal approach allowed the detection of 40 regions (P less than 0.001). Sensitivity and specificity for the detection of abscesses associated with endocarditis were 28.3 and 98.6 percent, respectively, for transthoracic echocardiography and 87.0 and 94.6 percent for transesophageal echocardiography; positive and negative predictive values were 92.9 and 68.9 percent, respectively, for the transthoracic approach and 90.9 and 92.1 percent for the transesophageal approach. Variation between observers was 3.4 percent for transthoracic and 4.2 percent for transesophageal echocardiography.

CONCLUSIONS

The data indicate that transesophageal echocardiography leads to a significant improvement in the diagnosis of abscesses associated with endocarditis. The technique facilitates the identification of patients with endocarditis who have an increased risk of death and permits earlier treatment.

Eustachian valve endocarditis

M mode and cross sectional echocardiography showed a highly mobile globular pedunculated mass(3.0 cm long with a maximum diameter of i.5 cm) attached to the eustachian valve in a heroin addict with staphylococcal endocarditis.

Bacterial endocarditis at a small community hospital

Clinical features, microbiology, and predisposing factors are described in 56 patients with bacterial endocarditis (BE) treated over a 12-year period at a small community hospital in Hawaii. The average age of patients was 52.0 years. The mean duration of symptoms was 28.8 days (range 1 to 240 days). Streptococci was the most frequently identified causative organism, present in 61% of the cases. Gram-negative bacilli were isolated from six patients (11%). Fourteen patients (25%) required cardiac surgery; the most common condition leading to surgery was severe valvular insufficiency, followed by congestive heart failure and recurrent embolism. Eighty-two percent of the patients in the series survived. The leading causes of death were congestive heart failure and cerebrovascular accidents.

Nonenterococcal group D streptococcal septicemia: association with unrecognized endocarditis

68 patients presented to the Veterans General Hospital, Taipei with nonenterococcal group D streptococcal septicemia in the years 1985-1987. 36 patients (53%) had nonenterococci as part of a polymicrobial bacteremia. The large intestine was not examined in most patients. Five patients (7%) had associated colonic carcinoma, and 17 patients (25%) had colorectal diseases. Only 7/68 patients (10%) were clinically diagnosed as having infective endocarditis by the doctors in charge. The others were regarded as having septicemia. The charts of these patients were reviewed retrospectively to diagnose infective endocarditis based on strict definitions. One (1%) had definite endocarditis proved at autopsy. 16 patients (24%) had probable endocarditis due to the presence of either a new regurgitant murmur or both a predisposing heart disease and embolic phenomena; 39 (57%) had possible endocarditis based on evidence of having either a predisposing heart disease or embolic phenomena; and only 12 (18%) had no evidence of endocarditis. 27 patients (40%) had at least one predisposing heart disease associated with endocarditis. 51 patients (75%) had at least one lesion suggesting embolic phenomena. 30 patients (44%) had electrocardiographic abnormalities. This high incidence of arrhythmia in nonenterococcal septicemia is of particular interest and could be related to cardiac involvement in some patients. The overall mortality, 62% (42/68), was extremely high in our series, but in those who were clinically diagnosed and treated as infective endocarditis, the mortality was low, 14% (1/7). We suggest all patients with nonenterococcal septicemia associated with either heart disease or lesions of CNS, lung, heart, kidney or limbs suggesting embolic phenomena should be regarded as having possible or probable endocarditis. Treating such patients as having infective endocarditis may reduce the mortality in nonenterococcal septicemia.

Cardiac evaluation of the patient with stroke

Coronary artery disease and ischemic cerebrovascular disease are leading causes of morbidity and mortality in the United States. Coronary artery disease often coexists with asymptomatic carotid artery atherosclerosis, transient ischemic attacks, or ischemic stroke. Numerous studies have shown that mortality from all forms of ischemic cerebrovascular disease is primarily due to coronary artery disease. Thus, there is increasing interest in identifying coronary artery disease in patients with cerebrovascular disease, including those without clinical manifestations of heart disease. We review the use of current noninvasive techniques to detect coronary artery disease and present practical approaches to screen for ischemic heart disease. Current diagnostic imaging methods for potential cardioembolic sources of cerebral infarction are also discussed.