Prosthetic valve endocarditis

Viridans streptococcal (Streptococcus mitis) biosynthetic aortic prosthetic valve endocarditis (PVE) complicated by complete heart block and paravalvular abscess

Prosthetic valve endocarditis (PVE) may be classified clinically as early (<60 days) or late (>60 days) post-valve replacement PVE. The pathogens of early versus late PVE differ in type and virulence. Early PVE pathogens are virulent, for example, Pseudomonas aeruginosa and Staphylococcus aureus. Late PVE pathogens resemble those of subacute bacterial endocarditis and are due to relatively avirulent and noninvasive organisms, for example, viridans streptococci. Viridans streptococci vary in their invasiveness and abscess potential. Myocardial abscess and complete heart block are rare complications of late PVE due to viridans streptococci. We present an unusual case of Streptococcus mitis late aortic PVE complicated by aortic root abscess, myocardial abscess, and complete heart block.

Pseudoaneurysm of mitral-aortic intervalvular fibrosa

Pseudoaneurysm of the mitral-aortic intervalvular fibrosa (MAIVF) is one of the rare complications of infective endocarditis. Echocardiography plays an important role in the diagnosis of this condition. Transesophageal echocardiography (TEE) is generally superior to the transthoracic approach in the evaluation of the complications resulting from infective endocarditis. In this report, we discuss a case of infective endocarditis complicated by the development of a pseudoaneurysm of the MAIVF. The anatomic relationship of structures contiguous to the MAIVF and the salient echocardiographic findings of this clinical condition are presented. At surgery the diagnosis was confirmed and appropriate treatment instituted. The postoperative course was uncomplicated.

Closure of prosthetic paravalvular mitral regurgitation with the Gianturco-Grifka vascular occlusion device

Paravalvular regurgitation associated with prothetic mitral valves is often a consequence of infectious endocarditis. The condition is usually treated with debridement and repeat surgical valve replacement. However, repeated operations are associated with high risk. This report describes a case of successful transcatheter treatment of severe paravalvular mitral regurgitation and pulmonary edema in a patient in whom repeat mitral valve replacement was not believed possible.

Vegetative infection of transjugular intrahepatic portosystemic shunts

BACKGROUND & AIMS

The occurrence of and the clinical picture of infection of transjugular intrahepatic portosystemic shunts (TIPS) has not been described previously. We describe the clinical features, associated pathogens, results of treatment of a previously unreported complication of TIPS, and primary infection of TIPS occurring after formation of the neointima.

METHODS

Patients with TIPS and fever were evaluated to exclude other sources of infection. The diagnosis was based on the occurrence of fever with positive blood cultures and either a thrombus or vegetations on the stent or persistent bacteremia in a patient with a TIPS and no other detectable source of infection despite an extensive search.

RESULTS

Eight patients met diagnostic criteria. Two of 8 cases occurred within 10 days of TIPS manipulation despite antibiotic administration before the procedure. The clinical features included fever (8 patients), tender hepatomegaly (5 of 8), hypoxemia (2 of 8), septic pulmonary emboli (1 of 8), septic shock (2 of 8), neutrophilia (5 of 8), and subsequent development of necrotizing fasciitis (1 of 8). Blood cultures were positive in all cases. The organisms included oral and enteric aerobic gram-negative bacteria in 7 of 8 patients and Candida in 1 patient. All 8 responded to administration of antibiotics. Two patients died of myocardial infarction and alcoholic hepatitis, respectively.

CONCLUSIONS

Infective endotipsitis is an uncommon complication of TIPS. Recognition of its clinical features will facilitate diagnosis. Most patients responded to antibiotic therapy.

Echocardiography and Doppler assessment of prosthetic heart valves with transesophageal echocardiography

This article examines the use of transesophageal echocardiography (TEE) in the assessment of prosthetic heart valves. A summary of the commonly used artificial valves and their physiologic regurgitant flow patterns, as identified by color Doppler imaging, is presented. The hemodynamic evaluation of prosthetic valve stenosis using Doppler techniques is reviewed, and the diagnostic utility of TEE in identifying the complications of cardiac prostheses is discussed.

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.

An emergency physician's guide to prosthetic heart valves: valve-related complications

Serious valve-related complications that occur in patients with prosthetic valves have been discussed. The emergency physician's role primarily is to recognize the high probability that one of these serious complications exists and hospitalize the patient so that rapid definitive diagnoses and therapeutic decisions are not delayed.

Legionella prosthetic-valve endocarditis

Since 1982 seven patients at Stanford University Medical Center have been shown to have prosthetic-valve endocarditis caused by Legionella pneumophila or L. dumoffii. We studied the clinical features of legionella endocarditis at the time of diagnosis and performed a case-control study to analyze risk factors for the infection. All patients with endocarditis had a chronic course (3 to 19 months after surgery) of fever, night sweats, weight loss, and anemia, but no embolic events or immune-complex deposition disease. Five patients required surgical replacement of their infected prosthetic valves. The case-control study revealed that during the early postoperative period, patients who later contracted legionella endocarditis were more likely to have had symptoms and signs attributable to postcardiomyotomy syndrome than were patients who did not contract endocarditis (P less than 0.013). Examination of the legionella isolates by means of molecular techniques demonstrated that the Stanford L. pneumophila isolates were genotypically identical to isolates from the hospital drinking water. L. dumoffii isolates from patients with endocarditis were derived from a single strain apparently unique to this medical center. We conclude that legionella infection was nosocomially acquired in the perioperative period. These cases demonstrate an expanding spectrum of illness caused by legionella species and emphasize the need to consider legionella as a cause of "culture-negative" endocarditis.

Infections in prosthetic devices

Infection in prosthetic devices is a rare but potentially serious complication of prosthesis implant surgery. Infections associated with a variety of permanently implanted devices are reviewed in the context of recent knowledge of the host-prosthesis interaction.