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Background: Infective endocarditis in children is rare, and most reports describe the experience in referral centers. The purpose of our study was to assess the characteristics of children with infective endocarditis in a large national sample., Methods and Results: We analyzed hospital discharge records with International Classification of Diseases, ninth revision, codes indicating infective endocarditis among admissions of patients <21 years of age in the Kids' Inpatient Databases 2000 and 2003; analyses for the 2 years were combined. In 1588 hospitalizations, the age distribution was bimodal, with peaks in infancy and late adolescence. The organism was coded in 632 admissions; Staphylococcus aureus was most common (57%), followed by the viridans group of streptococci (20%). Preexisting heart disease was present in 662 patients admitted (42%), among whom 81% had congenital heart disease, 8% had prosthetic valve endocarditis, and 5% had rheumatic heart disease. In-hospital mortality occurred in 84 patients (5%), 38 with preexisting heart disease. Death occurred in 12 of 25 patients (48%) with tetralogy of Fallot and pulmonary atresia, and 4 of 54 (8%) with prosthetic valve endocarditis. Among 46 deaths without preexisting heart disease, S aureus was the causative organism in 13 of 14 patients (93%) beyond infancy; among 32 infants who died, 10 (31%) were premature., Conclusions: In 2000 and 2003, we found a continuing shift in the epidemiology of pediatric infective endocarditis toward a higher proportion of children without preexisting heart disease. Risk factors for mortality included some forms of congenital heart disease and, among patients without preexisting heart disease, premature/neonatal age and S aureus as an etiologic agent.

Background: The causes of aortic regurgitation (AR) severe enough to warrant aortic valve replacement (AVR) have received little attention in the last 20 years., Methods and Results: We analyzed the causes of pure AR in 268 patients > 20 years of age having isolated AVR at Baylor University Medical Center from 1993 to 2005 that was unassociated with mitral stenosis, mitral valve replacement, or a previous operation involving a cardiac valve or ascending aorta. In 122 patients (46%), the AR resulted from a problem with the aortic valve: congenital malformation unassociated with infective endocarditis, 66 patients (54%); infective endocarditis, 46 patients (38%; 15 with bicuspid valves); probable rheumatic heart disease, 8 patients (6%); and miscellaneous, 2 patients (2%). In the other 146 patients (54%), the AR was the consequence of a condition affecting the ascending aorta: dissection, 28 patients (19%); the Marfan syndrome or its forme fruste variety, 15 patients (10%); aortitis, 12 patients (8%), and in the remaining 91 patients (62%), the cause of the AR was not determined. This latter group was the oldest (mean age 66 years), 83 (91%) had hypertension, 26 (29%) had small calcific deposits in the valve cusps, and 46 (51%) had simultaneous coronary artery bypass grafting., Conclusions: The causes of pure AR severe enough to warrant isolated AVR are diverse. The most common category in this study was "cause unclear."

Background: The incidence of embolic events (EE) and death is still high in patients with infective endocarditis (IE), and data about predictors of these 2 major complications are conflicting. Moreover, the exact role of echocardiography in risk stratification is not well defined., Methods and Results: In a multicenter prospective European study, including 384 consecutive patients (aged 57+/-17 years) with definite IE according to Duke University criteria, we tested clinical, microbiological, and echocardiographic data as potential predictors of EE and 1-year mortality. Transesophageal echocardiography was performed in all patients. Embolism occurred before or after IE diagnosis (total-EE) in 131 patients (34.1%) and after initiation of antibiotic therapy (new-EE) in 28 patients (7.3%). Staphylococcus aureus and Streptococcus bovis were independently associated with total-EE, whereas vegetation length >10 mm and severe vegetation mobility were predictors of new-EE, even after adjustment for S aureus and S bovis. One-year mortality was 20.6%. In multivariable analysis, independently of the other predictors of death (age, female sex, creatinine serum >2 mg/L, moderate or severe congestive heart failure, and S aureus) and comorbidity, vegetation length >15 mm was a predictor of 1-year mortality (adjusted relative risk=1.8; 95% CI, 1.10 to 2.82; P=0.02)., Conclusions: In IE, vegetation length is a strong predictor of new-EE and mortality. In combination with clinical and microbiological findings, echocardiography may identify high-risk patients who will need a more aggressive therapeutic strategy.

Background: Despite advances in medical, surgical, and critical care interventions, infective endocarditis remains a disease that is associated with considerable morbidity and mortality. The continuing evolution of antimicrobial resistance among common pathogens that cause infective endocarditis creates additional therapeutic issues for physicians to manage in this potentially life-threatening illness., Methods and Results: This work represents the third iteration of an infective endocarditis "treatment" document developed by the American Heart Association under the auspices of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease of the Young. It updates recommendations for diagnosis, treatment, and management of complications of infective endocarditis. A multidisciplinary committee of experts drafted this document to assist physicians in the evolving care of patients with infective endocarditis in the new millennium. This extensive document is accompanied by an executive summary that covers the key points of the diagnosis, antimicrobial therapy, and management of infective endocarditis. For the first time, an evidence-based scoring system that is used by the American College of Cardiology and the American Heart Association was applied to treatment recommendations. Tables also have been included that provide input on the use of echocardiography during diagnosis and treatment of infective endocarditis, evaluation and treatment of culture-negative endocarditis, and short-term and long-term management of patients during and after completion of antimicrobial treatment. To assist physicians who care for children, pediatric dosing was added to each treatment regimen., Conclusions: The recommendations outlined in this update should assist physicians in all aspects of patient care in the diagnosis, medical and surgical treatment, and follow-up of infective endocarditis, as well as management of associated complications. Clinical variability and complexity in infective endocarditis, however, dictate that these guidelines be used to support and not supplant physician-directed decisions in individual patient management.

Background: Mammalian platelets contain small, cationic, staphylocidal peptides, termed thrombin-induced platelet-microbicidal proteins (tPMPs). Evidence suggests that tPMPs play a key role in host defense against endovascular infections, such as infective endocarditis (IE). In the present study, we evaluated the influence of differences in staphylococcal tPMP-susceptibility profiles in vitro on disease severity in experimental IE., Methods and Results: Experimental IE was induced in rabbits with either a tPMP-susceptible or an isogenic tPMP-resistant Staphylococcus aureus strain. Vegetation size, left ventricular fractional shortening, and onset of aortic valvular regurgitation were serially assessed by echocardiography over an 11-day postinfection period. In addition, blood cultures were performed daily. Parameters delineated at autopsy included vegetation weights; bacterial densities in vegetations, myocardium, and kidneys; extent of valvular and perivalvular tissue damage; and renal embolization. The following significant differences were observed in animals infected with the tPMP-susceptible versus the tPMP-resistant S aureus strain: substantially lower bacteremia rates (P=0.02); reduced vegetation growth (P<0.001) and weight (P<0.001); a later onset of aortic valvular regurgitation (P=0.0039); increased preservation of left ventricular function (P<0.001); reduced valvular tissue damage (P=0.01) and perivalvular inflammation (P=0.015); and reduced bacterial densities in vegetations (P<0.001) and kidneys (P<0.01)., Conclusions: The in vitro tPMP-susceptibility profile in S aureus substantially affects a number of well-defined cardiac and microbiological parameters related to disease severity and prognosis in IE. These findings underscore the likelihood that platelets mitigate the pathogenesis of endovascular infections via local secretion of antimicrobial peptides.

Background: The literature on infective endocarditis in hypertrophic cardiomyopathy (HCM) is virtually confined to case reports. Consequently, the risk of endocarditis in HCM remains undefined., Methods and Results: We assessed the occurrence of endocarditis in 810 HCM patients evaluated between 1970 and 1997. Endocarditis was diagnosed in 10 patients, 2 of whom were excluded from analysis of prevalence and incidence because they were referred for acute endocarditis. At first evaluation, echocardiographic features consistent with prior endocarditis were identified in 3 of 808 patients, a prevalence of 3.7 per 1000 patients (95% CI, 0.8 to 11). Of 681 patients who were followed, 5 developed endocarditis, an incidence of 1.4 per 1000 person-years (95% CI, 0.5 to 3.2); outflow obstruction was present in each of these 5 patients and was associated with the risk of endocarditis (P=0.006). In the 224 obstructive patients, incidence of endocarditis was 3.8 per 1000 person-years (95% CI, 1.6 to 8.9) and probability of endocarditis 4. 3% at 10 years. Left atrial size was also associated with the risk of endocarditis (P=0.007). In patients with both obstruction and atrial dilatation (>/=50 mm), incidence of endocarditis increased to 9.2 per 1000 person-years (95% CI, 2.5 to 23.5). Analysis of all 10 patients with endocarditis identified outflow obstruction in each and atrial dilatation in 7., Conclusions: Endocarditis in HCM is virtually confined to patients with outflow obstruction and is more common in those with both obstruction and atrial dilatation. These results indicate that antibiotic prophylaxis is required only in patients with obstructive HCM.

Background: Secondary involvement of the mitral-aortic intervalvular fibrosa and the anterior mitral leaflet (subaortic structures) can occur in patients with aortic valve endocarditis. The secondary involvement of these structures occurs as a result of direct extension of the infection from the aortic valve or as a result of an infected aortic regurgitant jet striking the ventricular surfaces of the mitral-aortic intervalvular fibrosa and the anterior mitral leaflet. The abscess of mitral-aortic intervalvular fibrosa can expand to form an aneurysm. Subsequently, this mitral-aortic intervalvular fibrosa aneurysm can develop a perforation and communicate with the left atrium, resulting in the systolic regurgitation of blood from the left ventricular outflow tract into the left atrium. Secondary infection can also occur on the ventricular surface of the anterior mitral leaflet and result in the formation of an aneurysm or perforation of anterior mitral leaflet., Methods and Results: This study examines the utility of transesophageal echocardiography in the detection of these subaortic complications in 55 consecutive patients with aortic valve endocarditis. A total of 24 patients (44%) had involvement of subaortic structures, including four with an abscess in the mitral-aortic intervalvular fibrosa, four with mitral-aortic intervalvular fibrosa aneurysm, seven with perforation of the mitral-aortic intervalvular fibrosa with communication into the left atrium, two with an aneurysm of the anterior mitral leaflet, and seven with perforation of the anterior mitral leaflet. The transesophageal echocardiographic findings were confirmed at surgery in 20 patients and at necropsy in two. By comparison, transthoracic echocardiography visualized these lesions in five of 24 patients (21%), including none of four with mitral-aortic intervalvular fibrosa abscesses, two of four with mitral-aortic intervalvular fibrosa aneurysms, one of seven with mitral-aortic intervalvular fibrosa perforations, one of two with anterior mitral leaflet aneurysms, and one of seven anterior mitral leaflet perforations. Eccentric mitral regurgitation-type systolic jets were noted in eight additional patients by transthoracic color flow imaging, and this finding suggested the possibility of these unusual subaortic complications. If these patients are included, then transthoracic echocardiography suggested the presence of these subaortic complications in 13 of 24 patients (54%)., Conclusions: The results indicate that 1) involvement of the subaortic structures in patients with aortic valve endocarditis may be more common than previously recognized, 2) patients with aortic valve endocarditis and eccentric jets of mitral regurgitation on transthoracic echocardiography should undergo further evaluation by transesophageal echocardiography to exclude these unusual complications, 3) precise recognition of these complications is of value in the optimal medical and surgical management of these patients, and 4) these complications may be responsible for unexplained congestive heart failure and hemodynamic deterioration in some patients with aortic valve endocarditis.

The significance of septic emboli to the spleen is inferred by the frequency of septic emboli in general seen in patients with left-sided infective endocarditis who are referred for valve replacement. To determine the proper management of splenic infarcts and abscess due to septic emboli, we retrospectively reviewed the records of 108 patients with left-sided endocarditis who underwent valvular surgery at the University of Illinois Hospital from 1980 through 1988. Intravenous drug abuse was the etiology in 68% (n = 73). The incidence of splenic infarcts and abscess was 19% (n = 20), but an incidental finding of splenic infarcts was found in 38% (n = 11) of 29 asymptomatic patients who had computed tomograms. Streptococci and staphylococci were the causative organisms in 85% (n = 17). Localized findings were absent in 90% of splenic infarcts and abscesses. Abdominal computed tomograms were diagnostic of the sequelae of splenic septic emboli in 100%. No patient had intra-abdominal bleeding complications associated with cardiopulmonary bypass. Splenectomy was performed in 50% (n = 10) of patients 3-24 days (mean, 11.2 days) after valve replacement. Indications for splenectomy included persistent sepsis in 60% (n = 6), large (greater than 2 cm) and peripheral lesions in 30% (n = 3), and splenic rupture in 10% (n = 1). Perioperative mortality of patients who underwent splenectomy was 30% (n = 3). The following conclusions can be drawn: 1) Splenic septic embolus is common in endocarditis. 2) Abdominal computed tomography should be performed for all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

In order to assess the reliability of the echocardiogram in detecting valvular vegetations in patients with mitral valve prolapse (MVP), echocardiograms from 85 consecutive patients with mitral valve prolapse were reviewed. Eleven patients had thick shaggy echoes confined to the anterior mitral leaflet; eighteen patients had shaggy echoes on the posterior leaflet; and five had abnormal echoes on both the anterior and posterior leaflets. Only one patient had clinical evidence of infective endocarditis. Redundant leaflets which present multiple surfaces for the production of echoes may explain the abnormal echoes that were observed. Patients with echographic features suggesting mild prolapse less commonly exhibited shaggy leaflet echoes than those with more severe prolapse. Because a significant proportion (40%) of patients with MVP had shaggy echoes which closely resembled those seen in valvular vegetations, we feel that the echocardiogram is of limited value in diagnosing infective endocarditis in patients with mitral valve prolapse.

We present the apparently unique M-mode and two-dimensional echocardiographic features of a surgically confirmed pseudoaneurysm of the left ventricular outflow tract, which probably developed as a result of perforation of the mitral-aortic intervalvular fibrosa. Echocardiographic studies revealed an aneurysmal sac situated between the aortic root and the left atrium. The aneurysm expanded in systole and collapsed or emptied in diastole, suggesting direct communication with the left ventricle. Such an aneurysm must be differentiated from various pathologic findings of the aortic root. The location and characteristic motion during the cardiac cycle should alert the clinician to the correct diagnosis of such an aneurysm.

We studied the clinical and echocardiographic features of eight patients with infective pulmonary valve endocarditis. In two patients, the vegetation was limited to the pulmonary valve; in the six other patients, infective lesions were also present on the mitral or aortic valves. None of the patients were addicted to narcotics. Seven of the eight patients had underlying congenital heart disease. In six patients the organism responsible for the infective endocarditis was Streptococcus viridans. Two-dimensional echocardiography performed using a wide-angle sector scanner was more useful than M-mode echocardiography for evaluating patients with pulmonary valve endocarditis.

Controversy persists concerning the role of early surgical intervention in severe infective endocarditis (IE). We therefore reviewed 163 episodes of well-documented IE in which 32 cardiac operations were performed during the active phase of IE. Congestive heart failure (CHF) was the principal indication for surgery in 88% (28/32); systemic emboli, 1/32; and persisting sepsis, 3/32. Staphylococcus and enterococcus were the most common infecting organisms in the operative group (44% and 16% respectively). Surgical mortality (11/32,37%) did not differ (p greater than 0.05) from medical mortality (26/131,20%). All 11 operative deaths occurred in patients moribund prior to surgery, including three with preoperative cardiac arrest. Surgical patients undergoing preoperative cardiac catheterization demonstrated marked CHF: a mean left ventricular end-diastolic pressure of 25.3 mm Hg. The mean cardiac index in 8/11 surgical deaths was lower (p less than 0.05) vs surgical survivors: 2.21/min/m2 vs. 3.21/min/m2. Postoperative complications were rare in the 21 surgical survivors. There were no episodes of continued infection, prosthetic dehiscence, or advanced heart block; only one paravalvular leak; and one systemic embolus. These findings emphasize the high medical and surgical mortality in patients with IE, suggest that delayed operative intervention may be a major causative factor resulting in a high surgical mortality, and justify an aggressive surgical approach in patients with valve dysfunction and heart failure. These data indicate that survivors of surgical intervention during active IE have eradication of infection and few postoperative complications.

Bacterial endocarditis developed in 24 patients during follow-up in the Natural History Study. It occurred significantly more often in patients with ventricular septal defect (1.5/1000 patient-years) and aortic stenosis (1.8/1000 patient-years) than in those with pulmonary stenosis (0.2/1000 patient-years). Complications, especially emboli and aortic regurgitation, occurred in 50% of the patients. Overall mortality was 25%. Incidence rates were significantly greater for males than for females and greater for patients over 20 years of age than for younger patients. Patients who had had ventricular septal defect treated surgically had a lower incidence of endocarditis than non-surgical patients, whereas surgery did not reduce the incidence in patients with aortic stenosis. The estimated risk of contracting bacterial endocarditis prior to 30 years of age in a patient with medically-treated ventricular septal defect is 9.7%; the risk estimate for surgical patients in 2.0%. Although data regarding the use of prophylactic antibiotics were not available for patients in the Natural History Study, these results certainly suggest that continued antibiotic prophylaxis for dental and certain surgical procedures is mandatory for patients with aortic stenosis, even after successful cardiac surgery. It is the authors opinion that prophylaxis is probably less necessary for patients who have pulmonary stenosis, whether surgically treated or not, and for patients with documented complete closure of VSD.

This report describes the echocardiographic features seen in a case of bacterial endocarditis in which the aortic valve leaflets had been partially destroyed. The endocardiogram demonstrated unusual, disorganized echo patterns in the outflow tract of the left ventricle near the anterior leaflet of the mitral valve in diastole. These were shown to be continuous with similar disorganized echo patterns demonstrated in the aortic root in diastole. These echocardiographic abnormalities were no longer present after aortic valve replacement.

Echocardiographic features of a patient with sinus of Valsalva aneurysm rupture into the right atrium are described. The aneurysm presented as a dense echo-producing mass in the right atrium which descended into the tricuspid orifice during diastole and withdrew back into the atrium during ventricular systole. Pulmonic valve exho motion demonstrated early diastolic pulmonic valve opening indicating an early right ventricular diastolic pressure rise exceeding simultaneous pulmonary artery pressure. Since the aorta is the only source of early diastolic pressure in excess of pulmonary artery pressure available to the right heart, this finding of early diastolic pulmonic valve opening indicated the presence of a fistula between the aorta and right heart. Other interesting echocardiographic features of this case are also presented.

A significant number of patients with infective aortic valve endocarditis develop aortic annular abscess. Although antibiotics may occasionally sterilize an aortic root abscess, most patients require surgical intervention. A review of our experience with 21 consecutive patients surgically treated for aortic root abscess disclosed that 13 patients had prosthetic valve and eight had native aortic valve endocarditis. The predominant microorganism was Staphylococcus aureus, particularly in those patients with native aortic valve endocarditis. The abscess was limited to the aortic annulus in 10 patients and was either multiple or had perforated the left ventricular outflow tract in 11 patients. Most patients were desperately ill at the time of operation. Repair was accomplished by aggressive debridement of all apparently infected tissue and reconstruction of the left ventricular outflow tract with autologous pericardium. Although postoperative complications were common, only one patient died in hospital. Operative survivors have been followed up from 3 to 68 months (mean, 29 months). One patient died of complications of repair of a thoracoabdominal aneurysm 34 months after surgery; his prosthetic aortic valve and patch were intact at autopsy. No patient has experienced recurrent infection, pericardial patch aneurysm, or prosthetic valve dehiscence.

Severe aortic insufficiency may accelerate mitral valve closure. We noted this echocardiographic finding in several patients with the acute onset of severe aortic insufficiency. Accordingly, we examined our total echocardiographic series retrospectively for early closure of the mitral valve (ECMV) in the setting of aortic insufficiency and found it in 11 of 53 patients with confirmed aortic insufficiency. During our study ECMV was fortuitously found in two other patients without aortic insufficiency, ECMV occurred in late diastole following the echocardiographic "A" wave, often associated with s suppressed "A" wave (type "B" ECMV). ECMV presence and subtype, along with other clinical parameters, appeared to be useful in the serial evaluation of the patient with severe aortic insufficiency. Additionally, the analysis of ECMV type helped to clarify the mechanism and significance of the Austin Flint murmur. Analysis of 17 patients with and without ECMV, with severe aortic insufficiency judged clinically (NYHA functional class III or IV) and angiographically (3+), indicated that only ECMV patients had acute aortic insufficiency and demonstrated diminished left ventricular size following successful aortic valve replacement. Although due primarily to aortic insufficiency, ECMV could be influenced by rhythm or conducted abnormalities, co-existent cardiac lesions, and pharmacologic interventions. Exclusive of these factors, ECMV was an excellent sign of acute, torrential aortic insufficiency, and a simple noninvasive indicator of the patient requiring immediate aortic valve replacement.

Aortic valve rupture, secondary to aortic valve endocarditis, was diagnosed echocardiographically and closely followed preoperatively. The ruptured left coronary cusp of the aortic valve was seen as dense irregular echoes, located anteriorly during ventricular diastole, and protruding into the left ventricular outflow tract in an otherwise normally appearing aortic valve. These echocardiographic findings, when correlated with changes in the clinical status of the patient, prompted immediate cardiac catheterization and aortic valve replacement. Early echocardiographic detection of abnormal aortic cusps and variation from normal aortic root echo features should alert the physician to proceed to cardiac catheterization, and aortic valve replacement if necessary.

The results of surgical and non-surgical treatment of active infective endocarditis in 182 patients over a 10-year period were analyzed. Heart failure, annular and myocardial abscesses, heart block, and coronary embolism, seen most frequently with staphylococcal and fungal endocarditis, were the primary causes of death in both native valve endocarditis (NVE) and prosthetic valve endocarditis (PVE). In NVE, surgery significantly improved the survival in patients with moderate or severe heart failure (P less than 0.05) and in all patients with staphylococcal endocarditis (P less than 0.03). In PVE, surgery significantly influenced survival in patients with moderate or severe heart failure (P less than 0.05) and in the entire group with late PVE (P less than 0.01). Early surgery is recommended for patients with native valve endocarditis and moderate or severe heart failure; those patients with staphylococcal NVE, regardless of hemodynamic state, should undergo early valve replacement. Early surgery is recommended for PVE patients with moderate or severe heart failure. We also recommend early valve replacement for early and late staphylococcal PVE.

Infective endocarditis (IE) continues to be one of the most serious complications following cardiovascular surgery, particularly that for replacement of valves. In order to define more clearly the clinical course and the role of surgical therapy, clinical and necropsy data were reviewed in 16 adult patients with prosthetic aortic valvular endocarditis (PAVE) and compared with the experience cited in the literature. Positive blood cultures were obtained in each of the patients with bacterial endocarditis. Gram positive bacteria predominate and the onset of infection is usually later than 25 days postoperatively. In 11 of 16 patients, aortic insufficiency was recognized. Autopsy material demonstrated large perivalvular abscesses which loosened the attachment of the prosthetic valve in each case and which made successful operation unlikely. Aortic insufficiency appears to be of prognostic importance, since patients who developed aortic insufficiency early in the course of PAVE died. Survivors included patients who made an excellent response to medical therapy and who either did not develop aortic insufficiency or developed aortic insufficiency either late in the course or even after cure of PAVE, Poor response to medical therapy and progressive aortic insufficiency even in the absence of left ventricular failure appear to be indications for prompt surgical replacement of the prosthetic aortic valve.