Progressive Dyspnea in a Man With Recently Treated Presumed Endocarditis: The Usual Onset of Valvular Incompetence or More Complex Pathology?

A 51-year-old, 85-kg, 170-cm man with coronary artery disease, essential hypertension, hyperlipidemia, tobacco abuse, and obstructive sleep apnea was transferred to the authors' institution for evaluation of a 2-month history of recurrent fevers, chills, malaise, weakness, myalgia, and generalized arthralgias. The patient denied chest pain, dyspnea at rest or during exercise, palpitations, nausea, vomiting, and urinary symptoms. Two sets of blood cultures were positive for Streptococcus anginosus, but transthoracic echocardiography did not show vegetations. The patient was treated empirically for presumed infective endocarditis, initially with intravenous cefazolin and vancomycin, and subsequently with a 4-week course of intravenous ceftriaxone. He returned to the hospital shortly after completing antibiotic therapy complaining of a new 1-week histoiy of intermittent chest pressure, progressive dyspnea, first on exertion then at rest, orthopnea, and paroxysmal nocturnal dyspnea. The physical examination revealed a harsh grade IV of VI systolic murmur heard best over the cardiac apex. Rales were heard in the lower lung fields. A dental examination indicated the presence of multiple caries with oral fistulae. A chest radiograph demonstrated prominent pulmonary vasculature and interstitial edema consistent with mild congestive heart failure (not shown). The patient was treated with furosemide, which improved his symptoms. Transesophageal echocardiography (TEE) was performed as part of the diagnostic evaluation and revealed the following images (Figs 1-4; Videos clips 1-4). What is the diagnosis?