| Snapshot |
| A 50-year-old man presents to the emergency room for a fever that has persisted for several days. He denies any history of intravenous drug use or any congenital heart disease. Physical exam reveals nailbed splinter hemorrhages, Osler nodes on his fingers, and Janeway lesions on his palms and soles. Heart auscultation reveals a new murmur. An echocardiogram shows vegetations on the mitral valve, and blood cultures that were drawn 12 hours apart were positive for Streptococcus bovis. Antibiotic therapy is started and he is scheduled for a colonoscopy. |
| Introduction |
| Clinical definitioninflammation of the heart valve, typically secondary to infectionEpidemiologylocationmitral valve > tricuspid valvetricuspid valve disease is associated with intravenous (IV) drug use Staphylococcus aureus, Pseudomonas, Candidarisk factors rheumatic heart diseaseIV drug useimmunosuppressionprosthetic heart valvecongenital heart diseaseEtiologyacute endocarditisStreptococcus pneumoniaeStreptococcus pyogenesNeisseria gonorrheaStaphylococcus aureus IV drug users large vegetations seen on valvessubacute bacterial endocarditis is characterized by slower onset and less severe symptomsStreptococcus bovis (gallolyticus) in the setting of colon cancerEnterococcusin the setting of gastrointestinal/genitourinary proceduresStreptococcus viridansoften a complication of dental proceduresmakes dextrans, which binds to fibrin-platelet aggregates on the heart valvesStaphylococcus epidermidisoften in the setting of prosthetic valvesCandida albicansIV drug usersnon-infectious endocarditisLibman-Sacks endocarditis from systemic lupus erythematosusmitral or aortic valve involvementmarantic endocarditisfrom metastatic cancer seeding to the valvesvery poor prognosisPathogenesisendothelial damage on the surface of the cardiac valve can cause a thrombus to formfactors include turbulent blood flow that can damage endothelium, or deposition of fibrin-platelet aggregate on damaged endotheliumbacteria can then adhere to thrombusvegetations are caused by further depositions of fibrin and plateletsPrognosisoften presents as fever of unknown originendocarditis prophylaxis may be required before dental procedures |
| Presentation |
| Symptomspersistent fevers (the most common symptom)shortness of breathsystemic symptomsweaknessfevermalaisePhysical examnew murmur on auscultationfrom emboliRoth spots retinal hemorrhages on funduscopyJaneway lesions erythematous and nontender macules on palms or solesnail bed splinter hemorrhages from immune complex depositionOsler nodes tender nodules on fingers or toesglomerulonephritis |
| Imaging |
| Echocardiography indicationfor all patientsfindingsvegetations on valves |
| Evaluation |
| Labs positive blood cultures drawn at least 12 hours apart or multiple positive cultures (at least 3 of 4) with the first and last drawn at least 1 hour apartcomplete blood countanemiaserum creatinineto evaluate renal function (glomerulonephritis)Making the diagnosisbased on clinical presentation and Duke criteria pathologic criteriaculture of organismhistologic evidence of endocarditis from vegetation or intracardiac abscessclinical criteria: 1 of the following2 major criteria1 major and 3 minor criteria5 minor criteriaif blood cultures are negative but echocardiography shows endocarditis, consider 1 of the causes of Culture-Negative Endocardidtis (CNE)Coxiella burnetiiBartonella sppHACEK organismsHaemophilusAggregatibacterCardiobacteriumEikenellaKingella |
| Major | Minor |
| Positive blood cultures from 2 separate blood cultures drawn > 12 hours apart, or 3 out of 4 blood cultures that are positive, with first and last samples drawn 1 hour apartAbnormal echocardiogram with vegetation, abscess ,or partial dehiscence of prosthetic valve | FeverPresence of risk factors, including intravenous drug use, structural heart disease, prosthetic heart valve, dental procedures, or history of endocarditisVascular phenomena, including Janeway lesions, emboli, mycotic aneurysm, and conjunctival hemorrhageImmunologic phenomena, including glomerulonephritis, Osler nodes, and Roth spotsPositive blood cultures not meeting major criterionEchocardiographic findings consistent with endocarditis but not meeting major criterion |
| Differential |
| Osteomyelitisdistinguishing factoralthough this can present as fever of unknown origin, it typically lacks other findings of endocarditis and will not have vegetations on echocardiography |
| Treatment |
| Management approachchoice of antibiotics ultimately depend on causative agent and susceptibility as well as the presence of prosthetic material in the heartall antibiotics should be given intravenouslyMedicalvancomycin plus ceftriaxone or gentamicinindicationsfor patients with no prosthetic valveempiric antibiotic therapyvancomycin plus gentamicin and rifampinindicationsfor patients with prosthetic valveempiric antibiotic therapyOperativesurgical valve replacementindicationsheart failurepatients who are refractory to medical therapyabscess formationconduction disturbance |
| Complications |
| Cardiac complication sperivalvular abscessar rhythmiasheart failure Neurologic complications stroke |