Infective Endocarditis

Despite improvements in antibiotic regimens, patients with infective endocarditis (IE) have a high risk of valve replacement and death. Effective initial treatment depends on two steps: 1) diagnosis of the infecting organism, enabling specific antibiotic therapy, and 2) complete characterization of the anatomic extent of infection. Identification of the infecting organism requires culturing of blood prior to the initiation of antibiotics. Whenever possible, at least three sets of blood cultures should be obtained over 6 to 24 hours and held for 4 weeks if necessary to detect unusual or fastidious organisms. Transesophageal echocardiography (TEE) is usually necessary either to confirm the diagnosis or, most importantly, to identify the local complications of infection, many of which mandate surgery. Despite widespread availability, TEE remains under-used, both for the prevention of unnecessary antibiotic therapy in patients at very low risk for the disease and for the recognition of patients likely to benefit from early surgery. The selection of optimal antibiotic therapy depends on microbiologic data to establish the sensitivities of the specific causative organism. Short courses of antibiotic therapy and outpatient administration of intravenous antibiotics are useful in selected cases.

Deep venous thrombosis prophylaxis in patients with heart disease

Therapy to prevent deep venous thrombosis (DVT) and pulmonary embolism remains essential for inpatients, despite short periods of bedrest and hospitalization. Although most available data pertain to surgical patients, subgroups of medical patients are at moderate, high, and very high risk for DVT. These include patients admitted to the medical intensive care unit, those with the acute coronary syndromes, and those with congestive heart failure. Patients with unstable angina and acute myocardial infarction usually receive anticoagulation for other indications. However, for most patients with congestive heart failure (who will be at bedrest initially), DVT prophylaxis may be the only indication for anticoagulation. Recommended regimens are 5000 units of unfractionated heparin subcutaneously every 8 hours or enoxaparin 40 mg subcutaneously daily.

Transesophageal echocardiographic (TEE) evaluation of the aortic valve, left ventricular outflow tract, and pulmonic valve

The most important role of TEE in aortic valve disease is in the diagnosis of endocarditis and its complications. Examination of the annulus and subvalvular region is essential in any patient with possible aortic valve endocarditis. Assessment of the severity of aortic stenosis is a useful application of TEE when other data are either inconsistent or unavailable. TEE can provide a diagnosis of the origin of acute severe aortic insufficiency; this information may play a critical role in surgical planning. The diagnosis of a variety of aortic valve diseases can be made when TEE is performed to find an embolic source or to rule out dissection. In the case of mass lesions, such as papillary fibroelastomas and Libman-Sacks vegetations, the results of TEE carry major therapeutic implications. TEE offers generally excellent quality images of the LVOT and images of the RVOT and pulmonic valve that are superior to transthoracic echocardiography. The major clinical usefulness of TEE stems from its ability to identify pulmonic valve mass lesions and the causes of left and right ventricular outflow obstruction. TEE is also an important adjunct in the surgical management of left ventricular outflow obstruction.

Echocardiographic predictors of survival in low gradient aortic stenosis

Echocardiographic predictors of long-term survival for patients with low gradient aortic stenosis who undergo aortic valve replacement have not been previously reported. This study shows that patients with larger pre- and postoperative left ventricular volumes, a lower mean preoperative aortic pressure gradient, and failure of volumes to decrease and ejection fraction to increase postoperatively may have a poor prognosis.

Prevalence and diagnostic value of precordial murmurs for valvular regurgitation in obese patients treated with dexfenfluramine

Echocardiography is recommended for the detection of valvular regurgitation in asymptomatic users of anorexigens with a heart murmur. To determine the prevalence and diagnostic value of heart murmurs for valvular regurgitation, 223 patients receiving dexfenfluramine therapy for 6.9 months and 189 matched controls underwent history and cardiac auscultation by experienced noncardiologists unaware of echocardiography. Color Doppler echocardiograms were interpreted by 3 observers unaware of patients' clinical data. The frequency of at least mild regurgitation of any valve and abnormal regurgitation (moderate mitral or tricuspid or mild aortic regurgitation) were determined. Heart murmurs heard in 31 dexfenfluramine users (14%) and in 20 controls (11%) were all systolic and of grade I to II/VI intensity. Mild or worse regurgitation of any valve showed a trend in patients (18% vs 11.6% in controls, odds ratio [OR] 1.66, confidence interval [CI] 0.95 to 2.9, p = 0.08), but abnormal regurgitation (includes Food and Drug Administration grade regurgitation) was more common in patients (9% vs 3% in controls, OR 3.0, CI 1.18 to 7.65, p = 0.02). In dexfenfluramine users, heart murmurs were associated with at least mild or abnormal regurgitation (OR 3.1 and 3.05, 95% CI 1.34 to 7.13 and 1.1 to 8.67; p = 0.008 and 0.036, respectively), had a specificity of 89% and 88%, negative predictive value of 85% and 93%, but sensitivity of 37% and 30%, and positive predictive value of 35% and 19%, respectively. Most valves missed by cardiac auscultation had normal morphology and mild regurgitation. Finally, heart murmurs had better diagnostic value for either type of valvular regurgitation than heart murmurs and clinical variables or clinical variables alone. In summary, in dexfenfluramine users the prevalence of heart murmurs was low and their absence predicted absence of mild or worse regurgitation of any valve or abnormal valvular regurgitation. Therefore, cardiac auscultation should be the screening method of choice for detecting valvular regurgitation in users of anorexigens.

Prevalence and determinants of valvulopathy in patients treated with dexfenfluramine

BACKGROUND

Valve regurgitation has been associated with dexfenfluramine, but its prevalence and severity are uncertain. Additional factors that may contribute to valve regurgitation in patients exposed to this drug are poorly understood.

METHODS AND RESULTS

Echocardiography was performed on subjects recruited from 26 prescribing sites in 15 states. The total sample of 412 subjects included 172 dexfenfluramine patients and 172 unexposed controls matched for age, sex, and body mass index and 68 unmatched subjects meeting the same entry criteria (51 dexfenfluramine patients and 17 controls). Mean treatment duration was 6.9 months; mean interval from treatment discontinuation to echocardiogram was 8.5 months. Each echocardiogram was interpreted independently by 3 echocardiographers. FDA-grade regurgitation (at least mild aortic regurgitation or at least moderate mitral regurgitation) was significantly more frequent in dexfenfluramine patients (7.6% versus 2.1% for controls; P=0.01; odds ratio, 3.82). This difference was primarily due to more frequent mild aortic regurgitation in dexfenfluramine patients (6.3% versus 1.6% in controls; P<0.02; odds ratio, 4.15). No differences were found in sclerosis or mobility for either the aortic or mitral valve. Factors independently related to FDA-grade regurgitation or any grade of aortic regurgitation were older age, higher diastolic blood pressure at the time of echocardiography, and shorter time from drug discontinuation to echocardiogram.

CONCLUSIONS

Dexfenfluramine use is associated with an increase in the prevalence of abnormal valve regurgitation. Age and blood pressure may also affect the prevalence of regurgitation. Dexfenfluramine-related valve regurgitation may regress after drug discontinuation.

Flow dependence of valve area in aortic stenosis: relation to valve morphology

OBJECTIVES

We sought to develop an index of flow dependence of valve area in aortic valve (AoV) stenosis and to determine whether this index is related to structural characteristics of the diseased valve.

BACKGROUND

Many studies of AoV stenosis using Gorlin or continuity equation methods have demonstrated flow dependence (an increase in valve area with increased flow). Variation in flow dependence between patients despite similar flow rates remains unexplained.

METHODS

Dobutamine Doppler echocardiography was used to calculate flow rate and valve area by the continuity equation in 27 patients with aortic stenosis. For each patient the slope of the regression line of valve area to flow rate was determined (slope of flow dependence). Transesophageal echocardiography was used to evaluate features of valve morphology potentially related to the etiology of AoV stenosis and the mechanism of flow dependence.

RESULTS

Mean slope of flow dependence was 0.28 cm2/100 ml per s (range -0.06 to 0.53); flow dependence was significantly >0 in 21 patients and was lower for bicuspid valves (slope 0.21 cm2/100 ml per s) than for tricuspid valves with <10% commissural fusion (slope 0.35, p < 0.01). Off-center/ovoid orifices demonstrated the least flow dependence (slope 0.19), whereas star-shaped orifices showed the most (slope 0.36, p < 0.01). Greater flow dependence was related to a lower percentage of commissural fusion (r = -0.46, p = 0.02) as well as diffuse sclerosis, primarily involving the cusp bodies, rather than localized sclerosis, with involvement of cusp margins.

CONCLUSIONS

The slope of flow dependence of valve area in AoV stenosis differs markedly between patients. More flow dependence was associated with tricuspid valves and the morphologic features characteristic of calcific AoV stenosis, whereas less flow dependence was associated with bicuspid valves and the features of rheumatic disease.

Valve excrescences: prevalence, evolution and risk for cardioembolism

OBJECTIVES

We sought to determine prospectively the prevalence, evolution and embolic risk of valve excrescences in normal subjects and patients with and without suspected cardioembolism.

BACKGROUND

Valve excrescences detected by transesophageal echocardiography (TEE) have been considered a cardioembolic substrate in selected patients.

METHODS

Ninety healthy volunteers (Group I) and 88 patients without suspected cardioembolism and a normal TEE (Group II) were studied and followed up clinically for 58 +/- 21 and 48 +/- 20 months, respectively. To assess the evolution of valve excrescences, 45 of these subjects underwent repeat TEE at 31 +/- 13 months. The findings in Groups I and II were compared with those of Group III--49 patients referred for TEE for suspected cardioembolism.

RESULTS

Valve excrescences were detected in 34 subjects (38%) in Group I and in 41 patients (47%) in Group II. In Group III, 20 patients (41%) had excrescences, but 85% of them had other potential cardiac or vascular sources of embolism. In all groups, mitral valve excrescences were predominant (68% to 76%), followed by aortic (38% to 50%) and right-sided valves (<10%). Excrescences were equally frequent in men and women and between all age groups studied. During follow-up in Groups I and II, excrescences persisted unchanged, and 1 (1.4%) of 74 patients with and 2 (2%) of 99 subjects without excrescences had cerebral ischemic events (80% power to detect a clinically meaningful difference of 4%).

CONCLUSIONS

Valve excrescences are common on the left-sided heart valves of normal subjects and patients regardless of gender and age; they persist unchanged over time and do not appear to be a primary source of cardioembolism.

An echocardiographic study of valvular heart disease associated with systemic lupus erythematosus

BACKGROUND

Valvular heart disease is the most important cardiac manifestation of systemic lupus erythematosus. We performed a study to determine the relation of valvular disease to other clinical features of lupus, whether or not the valve disease progresses, and the associated morbidity and mortality.

METHODS

We performed transesophageal echocardiography and rheumatologic evaluations in 69 patients with systemic lupus erythematosus. The echocardiographic findings were compared with those in 56 healthy volunteers. Fifty-eight patients (84 percent) had second evaluations a mean (+/-SD) period of 29 +/- 13 months later. The patients and controls were followed for 57 months.

RESULTS

Valvular abnormalities were common on the initial and the follow-up echocardiograms (in 61 and 53 percent of the patients, respectively). Valvular thickening was the predominant finding initially and on follow-up (in 51 and 52 percent of the patients, respectively), followed by vegetations (in 43 and 34 percent), valvular regurgitation (in 25 and 28 percent), and stenosis (in 4 and 3 percent). Valvular abnormalities frequently resolved, appeared for the first time, or persisted but changed in appearance or size between the two studies. Mild or moderate valvular regurgitation did not progress to become severe, and new stenoses did not develop. Neither the presence of valvular disease nor changes in the echocardiographic findings were temporally related to the duration, activity, or severity of lupus or to its treatment. The combined incidence of stroke, peripheral embolism, heart failure, infective endocarditis, and the need for valve replacement was 22 percent in the patients with valvular disease, but only 8 percent in those without it. A total of seven patients died during follow-up, in most cases as a result of valvular disease. Valvular abnormalities and complications were uncommon in the controls (occurring in 9 and 2 percent, respectively).

CONCLUSIONS

Valvular heart disease is common in patients with systemic lupus erythematosus, frequently changes over time, appears to be temporally unrelated to other clinical features of lupus, and is associated with substantial morbidity and mortality.

Value of the cardiovascular physical examination for detecting valvular heart disease in asymptomatic subjects

To determine the accuracy of the cardiovascular physical examination for the diagnosis of asymptomatic valvular heart disease (VHD), we prospectively studied 143 subjects, 68 apparent normal subjects and 75 patients with diseases known to produce VHD. All subjects underwent a complete physical examination with dynamic cardiac auscultation by a physician blinded to clinical data and compared with the results of transesophageal color Doppler echocardiography (TEE). By TEE, 33 subjects (23%), and by physical examination, 25 subjects (17%) had at least 1 form of VHD. Despite a high frequency of mild valve abnormalities and a 31% prevalence of functional murmurs, the physical examination showed a sensitivity of 70%, a specificity of 98% (confidence interval = 0.51 to 0.84, and 0.94 to 0.99, respectively), and a positive and negative predictive value of 92% for the diagnosis of VHD. Only 2 of the 10 patients with VHD by TEE, but not by physical examination, had clinically important VHD. We conclude that the physical examination is a sensitive and highly specific method of screening for VHD in subjects without cardiac symptoms. Therefore, its use should be encouraged rather than the routine application of echocardiography.

Regional left atrial stasis during atrial fibrillation and flutter: determinants and relation to stroke

OBJECTIVES

This study sought to 1) determine the location of left atrial stasis during atrial arrhythmia; 2) define the degree of stasis associated with significant risk of stroke; and 3) identify clinical or transthoracic echocardiographic data useful for predicting left atrial stasis.

BACKGROUND

Prior studies suggest that stroke during atrial arrhythmia is related to stasis in either the body of the left atrium or the appendage. Recent data indicate that appendage stasis is associated with appendage thrombus formation, but stroke during atrial arrhythmia occurs frequently in the absence of appendage stasis.

METHODS

Blood flow velocity was measured in multiple sites in the body of the left atrium and in the appendage by transesophageal pulsed wave Doppler echocardiography in 89 patients with atrial fibrillation or flutter. Regional velocities were related to the frequency of probable embolic stroke and to clinical and transthoracic echocardiographic variables.

RESULTS

The lowest velocity region was either the posterior left atrium or the appendage. Stroke frequency increased progressively and steeply with velocity < 15 cm/s in either region; this cutoff value had an 87% sensitivity and 40% specificity for stroke. Factors related to stasis were low left atrial ejection fraction, mitral regurgitation < 3+, fibrillation (vs. type I flutter), left ventricular dilation and mitral valve area < 2.0 cm2.

CONCLUSIONS

Posterior left atrial stasis appears to be as important as appendage stasis for the risk of stroke, which increases steeply with lower blood flow velocity in either region. Patients likely to have severe stasis during atrial arrhythmia are those with left ventricular dilation and low atrial ejection fraction accompanying left atrial dilation. Direct measurement of atrial velocity by transesophageal echocardiography appears to be useful for the identification of patients at risk for stroke during atrial arrhythmia.

Osteogenesis imperfecta and cardiovascular diseases

Aortic and mitral valvular insufficiency in patients with osteogenesis imperfecta result from an underlying defect in connective tissue formation. The surgical cases reported in the literature have included mechanical and bioprosthetic valve replacement as well as attempts at repair and reconstruction. Despite complications related to bleeding and tissue friability, acceptable results have been obtained. In this report, we describe aortic regurgitation secondary to osteogenesis imperfecta treated with homograft replacement. The unique cardiovascular complications of osteogenesis imperfecta and the available therapeutic options are discussed in light of the literature review.

Transesophageal echocardiography in endocarditis

TEE plays a central role in the diagnosis and management of infective endocarditis. In experienced hands this technique is probably over 90% sensitive and specific for the detection of intracardiac lesions associated with endocarditis. TEE should be performed as soon as possible once endocarditis is suspected. A technically adequate negative study almost always means a low probability of endocarditis. Transesophageal imaging appears to be an accurate method of detecting leaflet perforation as well as abscess and fistula formation.

Pulmonary vein thrombosis

Pulmonary vein thrombosis is difficult to diagnose clinically and requires a combination of conventional diagnostic modalities. Transesophageal echocardiography was used in the present case to readily diagnose this entity and follow thrombus regression on anticoagulant therapy. This limited experience suggests that transesophageal echocardiography may be the initial diagnostic study of choice for pulmonary vein thrombosis.

Transesophageal echocardiography in the diagnosis of aortic disease

Transesophageal echocardiography (TEE) has recently become a major diagnostic tool in aortic disease. By far the most important role of TEE is in the rapid diagnosis of acute aortic dissection. In this disease the sensitivity and specificity of TEE are both well more than 90%, patient risk is minimal, and the test can (and should) be done in the emergency department. Limitations of TEE include, in some cases, difficulty delineating involvement of the proximal arch, major branch vessels, and abdominal aorta. Another emergency department application of TEE is the assessment of patients suspected of traumatic aortic rupture. TEE also is being applied to the diagnosis of aortic protruding atheromas, thought to have significant embolic potential.

Systemic lupus erythematosus valve disease by transesophageal echocardiography and the role of antiphospholipid antibodies

OBJECTIVES

The aims of this study were to better characterize valve disease in systemic lupus erythematosus and to determine its association with antiphospholipid antibodies.

BACKGROUND

Estimates of the prevalence of valve disease in systemic lupus erythematosus have been higher in autopsy series than in clinical studies using transthoracic echocardiography. Antiphospholipid antibodies have been suggested to be a primary pathogenetic factor.

METHODS

Transesophageal echocardiography was performed on 1) 54 patients with lupus erythematosus, 22 of them with (group I) and 32 without (group II) antiphospholipid antibody; 2) on 10 patients with antiphospholipid syndrome (group III); and 3) on 35 normal subjects (group IV).

RESULTS

Patients in groups I and III had similar types and concentrations of antibodies. Leaflet thickening was found in 50% of group I, 47% of group II, 10% of group III and 9% of group IV patients (group I or II vs. group III or IV, p < 0.03). Leaflet thickening in patients with lupus erythematosus was diffuse; it usually involved the mitral and aortic valves and was associated with valve regurgitation (73%) or valve masses (50%). Valve masses were observed in 41% of group I, 25% of group II, 10% of group III and in none of group IV patients (group I or II vs. group IV, p < 0.002). Most valve masses in patients with lupus erythematosus were located near the base on the atrial side of the mitral valve or on the vessel side of the aortic valve, had variable size (0.2 to 0.85 cm2), shape and echodensity. Valve regurgitation was observed in 64% of group I, 59% of group II, 10% of group III and 20% of group IV patients (group I or II vs. group III or IV, p < 0.006). Moderate or severe regurgitant lesions were noted in 27% of group I and 25% of group II patients.

CONCLUSIONS

Lupus erythematosus valve disease is frequent (74%) regardless of the presence or absence of antiphospholipid antibodies. Therefore antiphospholipid antibodies may not be a primary pathogenetic factor. The characteristic appearance of leaflet thickening and masses in patients with lupus erythematosus may be unique.

The two-view radionuclide ventriculogram. Advantages of the LPO view

This report is a prospective study of 33 male patients who underwent both contrast ventriculography (CVG) and radionuclide ventriculography (RVG) within a 24-hour period. Expert, blinded observers graded the left ventricle's regional wall motion (RWM) in the left anterior descending (LAD), left circumflex (LCx), and posterior descending arterial (PDA) distributions on right anterior oblique (RAO), and left anterior oblique (LAO) CVGs, and on anterior (ANT), LAO, 70 degrees left anterior oblique (LAO70), and left posterior oblique (LPO) RVGs. When statistically compared with CVG RWM standard data, RVG studies composed of LAO and LPO views were equal to the RVG studies composed of ANT, LAO, and LAO70 views in assessment of the LAD and LCx distributions. The RVG with LAO and LPO views was superior to the RVG with ANT, LAO, LAO70 in the detection of the posterior descending artery RWM. The authors conclude that accurate assessment of RWM is efficiently performed with the RVG composed of LAO and LPO views.

Diagnostic value of transesophageal compared with transthoracic echocardiography in infective endocarditis

To compare the diagnostic value of transesophageal and transthoracic echocardiography in infective endocarditis, paired transesophageal and transthoracic echocardiograms were obtained prospectively for 66 episodes of suspected endocarditis in 62 patients. Echocardiographic results were compared with the presence or absence of endocarditis determined by pathologic or nonechocardiographic data from the subsequent clinical course. All echocardiograms were interpreted by an observer told only that the studies were from patients in whom the diagnosis of endocarditis was suspected. The diagnosis of endocarditis was eventually made in 16 of the 66 episodes of suspected endocarditis (14 by pathologic and 2 by clinical criteria). In 7 of 16 transthoracic and 15 of 16 transesophageal echocardiograms, endocarditis was diagnosed at a probability level of "almost certain," giving a sensitivity of 44% and 94%, respectively (p less than 0.01). For the remaining episodes, 49 of 50 transthoracic and all transesophageal studies yielded normal results, giving a specificity of 98% and 100%, respectively. This study suggests that transesophageal echocardiography is highly sensitive and specific for the diagnosis of infective endocarditis and significantly more sensitive than transthoracic echocardiography. Although echocardiography cannot rule out endocarditis, the high diagnostic sensitivity of transesophageal echocardiography results in a low probability of the disease when the study yields negative results in a patient with an intermediate likelihood of the disease.

Anomalous papillary muscle producing dynamic left ventricular outflow tract obstruction

A patient with a dynamic left ventricular outflow murmur was shown to have an anomalous anterolateral papillary muscle by transthoracic and transesophageal two-dimensional Doppler echocardiography. High late systolic outflow velocity and systolic anterior motion were demonstrated in the lateral outflow tract near the anomalous muscle, suggesting a role for the Venturi effect. This is the first confirmation by Doppler echocardiography of an anomalous papillary muscle contributing to abnormal left ventricular hemodynamics.

Echocardiography in valvular heart disease

In 1990, echocardiography continued to develop rapidly, with new applications in the operating room and new solutions to common problems in the management of valvular heart disease. The newly published experiences with transesophageal and epicardial intraoperative echocardiography from Duke and the Cleveland Clinic illustrate the utility of these methods. Refinement of our concepts of mitral valve prolapse has occurred, along with echo Doppler support for awaiting symptoms prior to valve replacement in aortic stenosis.

Transesophageal echocardiography in the assessment of aortic pathology

Transesophageal echocardiography is an excellent method for diagnosing aortic pathology, especially dissection, and has replaced transthoracic echocardiography for this purpose. Advantages of the transesophageal method are its speed, portability, and accuracy. Disadvantages are the requirements of operator skill and patient sedation, as well as poor visualization of the distal 2-3 cm of the ascending aorta. Transesophageal echocardiography may become the initial diagnostic procedure of choice when acute dissection is suspected.