A 55-year-old heroin addict presented to the emergency department, complaining of shaking chills and fevers for 2 weeks. On examination, there was a loud holosystolic murmur, maximally audible in the epigastric space, and a pulsatile liver. Subcutaneous nodular lesions were noted on his palms. Blood cultures grew Pseudomonas aeruginosa. After nearly completing a prolonged course of intravenous antibiotic therapy, the patient died in his washroom from an overdose of heroin. This sad tale, often tragically repeated, represents a continuing challenge to the medical community. The patients’ palm lesions noted were
Osler’s nodes, originally described in 1908 by Sir William Osler, considered by many the father of internal medicine. Osler was born in 1849 and died in 1919. He was an astute clinician and educator, with professorships at McGill University, University of Pennsylvania, Johns Hopkins University, and Oxford University. Osler defined “chronic” infectious endocarditis as an illness lasting longer than 3 months and characterized by low grade fevers. This syndrome was distinct from a “malignant” form, which resulted in early death. Blood cultures usually grew streptococci or, occasionally, staphylococci. Osler made a practice of following his patients to the autopsy table. Vegetations on valves from patients who died of the chronic form looked more like “warts,” and were neither ”ulcerating or very large.” Osler thought anti-streptococcal vaccines might be of some benefit. There was little else to offer. Regardless of the form, nearly all patients died.
In this review, I discuss current methods for the diagnosis and management of infective endocarditis. Cases seen in recent years will illustrate key points.
Case 1 A 39-year-old computer programmer complained of occipital headaches, migratory muscle pains, afternoon fevers, and a 15-pound weight loss for 2 months. He had previously enjoyed excellent health. On examination his temperature was 38.0°C. An apical systolic heart murmur was noted. A transthoracic echocardiogram (TTE) showed mitral regurgitation, with a probable vegetation on the mitral valve. Blood cultures were drawn and the patient was admitted to the hospital. The next day, a transesophageal echocardiogram (TEE) showed perforation of the posterior mitral leaflet. That evening, the patient developed severe right flank pain. CT scan showed infarcts in the right kidney and spleen. The next day the patient underwent urgent mitral valve repair and was dismissed 5 days later to complete a course of intravenous ceftriaxone. All blood cultures grew viridans streptococci, exquisitely susceptible to penicillin.
Comment: This patient represents classic “subacute” bacterial endocarditis with fever, weight loss, and a heart murmur. In most cases, he would be cured with medical therapy alone. However, a TEE showed a lesion that was not appreciated on the initial TTE, and he required urgent surgery to restore a failing mitral valve.
Although the patient had no identified skin or mucosal lesions, when present these suggest the diagnosis. The subconjunctivial sacs and soft palate should be examined for petechiae, the nail beds for splinter hemorrhages, and digits for Janeway lesions.
Osler’s definition of endocarditis included remittent fever, history of valvular heart disease, embolic features, skin lesions, and heart failure. These remain useful bedside observations, and positive blood cultures usually clinch the diagnosis. Perhaps the most important technical advance in recent years for diagnosis is the echocardiogram. The major Duke criteria, published in 1994, include a predictable bacterial organism in blood culture, multiple positive blood cultures with the same organism, or an echocardiogram with definite vegetation, abscess, or valve dehiscence. Any two of the above suffice for diagnosis of probable endocarditis. Accepted minor criteria consist of predisposing lesions, history of intravenous drug abuse, temperature higher than 38°C, vasculitis, skin lesions, or “suggestive” echocardiographic or microbiologic findings. Five of these, or three with one major criterion, support the diagnosis. Transesophageal is superior to transthoracic echocardiography and should be performed if the TTE is equivocal or non-diagnostic.