Infective endocarditis

A narrative review of echocardiography in infective endocarditis of the right heart

Infective endocarditis (IE) is characterized by bacterial or fungal masses that form in the cardiac chambers and valves, and in severe cases invade the endocardium or intra-cardiac vessels. Right-sided IE accounts for 5% to 10% of cases, with a low mortality cited at 6%. A history of intravenous drug abuse (IVDU) is present in 90% of isolated right-sided IE cases, with normal intra-cardiac anatomy prior to infection in approximately 80%. Nevertheless, up to 50% of patients require early surgical intervention which is associated with significant peri-operative morbidity. Echocardiography is the gold standard for diagnosis with a sensitivity of 80% for the transthoracic modality and 95% for transesophageal studies; it provides important clinical information regarding the severity of infection and development of secondary complications. This includes identification of active infective vegetations, healed IE, prosthetic valve IE, and abscess formation and rupture. Prompt clinical, microbiologic, and imaging assessment of patients with suspected left or right-sided IE is of paramount importance and is reflected in the modified Duke criteria, the well-validated algorithm for accurate and timely diagnosis of IE. Data suggests the criteria sensitivity may be decreased in right-sided IE only, and thus, care must be taken to perform skilled and detailed echocardiographic assessments of the right heart in suspected cases. Herein we provide a review of IE of the right heart, with a focus on pathophysiology and its echocardiographic presentation and characteristics.

Implantation of mitral, aortic, and tricuspid bioprostheses due to infective endocarditis with necessary reimplantation of the bioprosthetic aortic valve

The patient was admitted to the Department of Cardiac Surgery of the J. Struś City Hospital in Poznan due to infective endocarditis involving the aortic, mitral, and tricuspid valves. Implantation of three biological valve prostheses proceeded without complications. Starting on day 23, the patient's general condition deteriorated, with high fever. Despite postoperative antibiotic therapy, transesophageal echocardiography revealed the presence of vegetation on the bioprosthetic aortic valve. On the 46th day after the initial surgery, the patient required replacement of the aortic bioprosthesis, which exhibited the presence of numerous vegetations. The bioprosthetic mitral and tricuspid valves were not affected by the degenerative process. On the 12th day after the reimplantation of the bioprosthetic aortic valve, the patient was discharged from the hospital in good general condition.

Bacteremia after Endodontic Procedures in Patients with Heart Disease: Culture and Molecular Analyses

INTRODUCTION

Infective endocarditis (IE) is still associated with high mortality, and antibiotic prophylaxis strategies are under intense debate. We evaluated the incidence of bacteremia after root canal preparation in teeth with necrotic pulps and apical periodontitis.

METHODS

Blood samples were taken before and 5 and 30 minutes after endodontic treatment in teeth with apical periodontitis from individuals at high (n = 21) or no risk (n = 11) for IE. The former received prophylactic antibiotic therapy. Bacteriologic samples were taken from root canals before chemomechanical preparation to confirm pulp infection. Samples were subjected to aerobic and anaerobic culture and quantitative real-time polymerase chain reaction (qPCR), the latter to determine the total bacterial and streptococcal levels.

RESULTS

Culture revealed no bacteremia in all individuals. Analysis by qPCR showed that bacterial DNA occurred in all root canal samples. qPCR showed a similar incidence of bacteremia between patients who received or did not receive prophylactic antibiotic therapy (P > .05). In blood samples taken 5 minutes after endodontic procedures, bacteria were detected in 2 of 11 (18%) individuals not taking antibiotics and in 4 of 21 (19%) patients under prophylaxis. After 30 minutes, the incidence of bacteremia decreased to 2 of 21 (10%) in patients taking antibiotics and was undetectable in patients at no risk of IE. The incidence of bacteremia by streptococci was identical as that for total bacteria.

CONCLUSIONS

No detectable bacteremia was evident by culture after treatment of infected root canals. Molecular analysis revealed bacterial DNA and streptococci in blood from some patients without a significant difference between individuals receiving or not receiving antibiotic prophylaxis.

Advanced Echocardiographic Techniques in Detection of Cardiotoxicity

OPINION STATEMENT

As advancements are made in cancer treatment, there is an increasing recognition of the cardiotoxic potential of chemotherapies and the need to monitor for the development of cardiac dysfunction in survivors. Echocardiography is the cornerstone of cardiac imaging and provides a feasible and non-invasive method to assess cardiac dysfunction in patients with cancer. In recent years, there has been increasing research in echocardiographic techniques to improve diagnosis of cardiotoxicity, including a more accurate assessment of the left ventricular function and the detection of subclinical disease. These specialized techniques include stress and contrast echocardiography, three-dimensional echocardiography, diastolic dysfunction, tissue Doppler imaging, and strain parameters.

Pathophysiology of infective endocarditis

Infective endocarditis (IE) is an uncommon infection, occurring as a complication in varying percentages of bacteremic episodes. The ability of an organism to cause endocarditis is the result of an interplay between the predisposing structural abnormalities of the cardiac valve for bacterial adherence, the adhesion of circulating bacteria to the valvular surface, and the ability of the adherent bacteria to survive on the surface and propagate as vegetation or systemic emboli. Certain bacteria, if present in the bloodstream, may colonize the initially sterile vegetation composed of fibrin and platelets; bacterial growth enlarges the vegetation, further impeding blood flow and inciting inflammation that involves the vegetation and adjacent endothelium. The true incidence of endocarditis complicating each of the bacterial species causing IE is difficult to estimate. About 20 %-30 % of individuals with community-acquired staphylococcal bacteremia develop IE [1, 2].

Clinical presentations of unoperated and operated adults with congenital heart disease

The clinical presentation of adults with congenital heart disease (ACHD) is exceptionally diverse. Operated, unoperated acyanotic, and cyanotic patients often have similar physiologic characteristics, and thus shared clinical symptomatology. Five illustrative cases are included to highlight important considerations in the diagnosis and management of ACHD. This article focuses on epidemiology, natural history, clinical outcomes, and use of ancillary studies in commonly encountered cardiac defects.

Echocardiographic features of an unruptured mycotic aneurysm of the right aortic sinus of Valsalva

This report describes a 25-year-old man with a pierced tongue in whom Streptococcus constellatus endocarditis of the aortic valve developed. Bacterial endocarditis in this patient was complicated by the development of a mycotic aneurysm of the right aortic sinus of Valsalva. Transthoracic and transesophageal echocardiographic studies were useful for the diagnosis of this rare lesion. Findings were confirmed at operation.

[Infectious endocarditis: degree of discordance between clinical guidelines recommendations and clinical practice]

INTRODUCTION AND OBJECTIVES

The present study was made to investigate the degree of discordance between the recommendations of clinical guidelines and actual practice in the care of patients with infectious endocarditis.

MATERIAL AND METHODS

Data was gathered on 34 patients that were admitted to our hospital for native valve infection over a 4-year period. The degree of discordance (%) was obtained by comparing each clinical history with a catalog of 15 specific actions recommended in the clinical guidelines for four consecutive phases: pre-diagnosis, hospital diagnosis, antibiotic treatment, and surgical treatment. A system was constructed, scoring each phase with the greatest detected error (on a severity scale of 0 to 8 points) and adding together the scores for the four phases.

RESULTS

The mean degree of discordance was 30.5% (range, 0-66%). Scores of more than six points were clearly associated with an unfavourable evolution.

CONCLUSIONS

The recommendations of clinical guidelines for infectious endocarditis are inadequately followed in practice, which can affect the course of the disease. It is necessary to increase adherence to clinical guidelines in practice, in order to improve the care of patients with this serious disease.

Once-daily aminoglycosides in the treatment of gram-positive endocarditis

OBJECTIVE

To examine the role of once-daily aminoglycosides (ODA) in the treatment of gram-positive endocarditis.

DATA SOURCES

A MEDLINE search was conducted from January 1984 to August 1998, and a Current Contents search was performed from September 1998 to December 1998, using endocarditis or aminoglycoside as key words. In addition, relevant articles were cross-referenced to screen for additional information.

DATA EXTRACTION

Data published in English regarding the use of aminoglycosides in endocarditis are cited. Emphasis was placed on animal and human studies, but in vitro studies and review articles are also included.

DATA SYNTHESIS

Endocarditis and the pharmacology of aminoglycosides are briefly reviewed. ODA is an alternative to conventional dosing in the treatment of endocarditis. Extensive work in endocarditis has been done recently in animals and humans to add to our understanding. Limited clinical data exist to support the theoretical advantages of increased efficacy, reduced toxicity, and potential cost savings versus traditional synergistic aminoglycoside dosing. Optimal monitoring of ODA remains undefined.

CONCLUSIONS

Routine use of ODA for the treatment of endocarditis is not yet advocated. Promising supporting evidence and speculation of success of ODA in gram-positive endocarditis justify well-designed trials to further define its role in therapy.

Fatal Staphylococcus aureus infective endocarditis: the dental implications

Infective endocarditis remains an important and life-threatening infection despite improvements in diagnosis and management. There is currently a greater role for nosocomial acquisition of organisms and immunosuppression in the pathogenesis of this disease and emergence of a broader spectrum of infective organisms including those not commonly isolated from the mouth such as staphylococci. We report a case of infective endocarditis caused by Staphylococcus aureus in which the patient developed disseminated intravascular coagulation and multiple septic infarcts resulting in a frontal lobe brain abscess. Multiple dental extractions were complicated by delayed postextraction hemorrhage and the immediate cause of death was abdominal hemorrhage. The dental management in infective endocarditis should be planned in consultation with the attending physician, and should take into account both the causative organism and the presence of complications. When the oral cavity cannot be proven as the bacterial source for infective endocarditis, the immediate dental management should be directed toward improving the patient's oral hygiene and providing pain relief. Definitive long-term treatment, including any extractions, is ideally delayed until the patient has fully recovered from the infective endocarditis and its attendant complications.

Acute infective endocarditis. Diagnostic and therapeutic approach

Acute bacterial endocarditis (ABE) is clinically distinct from subacute bacterial endocarditis in terms of pathologic virulence, acuteness and severity of illness, complications, and prognosis. The term infectious endocarditis may be useful as a general term but conveys no meaningful clinical information. ABE presents as an acute, fulminant intracardiac infection with fevers (temperature > 102 degrees F) that are caused by highly virulent known pathogens. Septic embolic phenomena, valve dysfunction, and congestive heart failure are characteristic. Parenteral and oral antibiotic treatment regimens are discussed.