A 58-year-old woman comes to the physician because of a two-week history of malaise, low-grade fevers, and poor appetite. She was hospitalized one month ago for a complicated urinary tract infection and underwent ureteroscopy due to a distal ureteral stone. Her other medical problems include hypertension, hepatitis C, and chronic lower back pain. Her current medications include hydrochlorothiazide and amlodipine.
Her temperature is 38.0 C (100.4 F), blood pressure is 120/70 mm Hg, pulse is 88/min, and respirations are 14/min. Physical examination reveals a soft, 2/6 decrescendo-type murmur at the left sternal border. A small petechial lesion is noted on her right big toe.
An EKG shows normal sinus rhythm. Transesophageal echocardiography (TEE) shows a 0.7 cm mobile mass attached to the non-coronary cusp of the aortic valve as well as mild-to-moderate aortic regurgitation. Blood cultures grow Enterococcus faecalis susceptible to ampicillin and gentamicin. Intravenous antibiotics are initiated.
On the fifth day of hospitalization, the patient still complains of malaise. Her temperature is 38.2 C (100.7 F). Physical examination shows a soft, 2/6 decrescendo-type murmur at the left sternal border, which is unchanged from admission. Repeat EKG is shown in this exhibit.
Which of the following is the most likely diagnosis?

Question

A 58-year-old woman comes to the physician because of a two-week history of malaise, low-grade fevers, and poor appetite.  She was hospitalized one month ago for a complicated urinary tract infection and underwent ureteroscopy due to a distal ureteral stone.  Her other medical problems include hypertension, hepatitis C, and chronic lower back pain.  Her current medications include hydrochlorothiazide and amlodipine.
Her temperature is 38.0 C (100.4 F), blood pressure is 120/70 mm Hg, pulse is 88/min, and respirations are 14/min.  Physical examination reveals a soft, 2/6 decrescendo-type murmur at the left sternal border.  A small petechial lesion is noted on her right big toe.
An EKG shows normal sinus rhythm.  Transesophageal echocardiography (TEE) shows a 0.7 cm mobile mass attached to the non-coronary cusp of the aortic valve as well as mild-to-moderate aortic regurgitation.  Blood cultures grow Enterococcus faecalis susceptible to ampicillin and gentamicin.  Intravenous antibiotics are initiated.
On the fifth day of hospitalization, the patient still complains of malaise.  Her temperature is 38.2 C (100.7 F).  Physical examination shows a soft, 2/6 decrescendo-type murmur at the left sternal border, which is unchanged from admission.  Repeat EKG is shown in this exhibit. 
Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec193a_9739_fc91_853d_b19d9b3d9b84_MD0002_00 This patient presents with aortic valve infective endocarditis (IE), likely due to bacteremia from her previous complicated urinary tract infection requiring ureteroscopy. The aortic valve and its annulus are more susceptible to abscess formation from IE; seen in up to 30-40% of patients in some studies. The abscess can extend from the aortic valve into the adjacent conduction tissue near the AV node and lead to various heart blocks. Less commonly, the abscess can extend into the ventricular septum and cause interventricular conduction delays. This patient's EKG reveals a new 1^st degree AV block, which is concerning for a perivalvular abscess. A repeat TEE is necessary to confirm the diagnosis. Surgery is indicated for a perivalvular abscess or fistula formation, valvular stenosis or regurgitation causing heart failure, fungal IE, and vegetations > 1 cm with or without embolic events. (Choice A) Ampicillin most commonly causes fever, rash, and sometimes bone marrow suppression. Gentamicin most frequently causes ototoxicity and nephrotoxicity. Neither drug is commonly associated with cardiac conduction defects. (Choice B) Coronary artery embolism with resultant myocardial infarction is a rare complication of IE, but an EKG would typically show findings of ischemia (e.g., ST elevation or depression, T wave inversions). (Choice C) Pericarditis is also a rare complication of IE and would have diffuse ST elevation with PR segment depression on EKG. (Choice E) Sinus node dysfunction is not usually a complication of IE. EKG findings of sinus node dysfunction would include severe bradycardia or sinus arrest (or exit block), which are not seen on this EKG. Educational objective: An EKG showing a new-onset prolonged PR interval in patients with aortic valve endocarditis suggests a perivalvular abscess causing heart block. Transesophageal echocardiography can confirm the diagnosis, and surgery is the definitive therapy. __________ References: Valve ring abscess in active infective endocarditis. Frequency, location, and clues to clinical diagnosis from the study of 95 necropsy patients. (http://www.ncbi.nlm.nih.gov/pubmed/1277418) Clinical features and outcome of non-drug-addicted patients with infective endocarditis and perivalvular abscess. (http://www.ncbi.nlm.nih.gov/pubmed/16359062) Early clinical course and long-term outcome of patients with infective endocarditis complicated by perivalvular abscess. (http://www.ncbi.nlm.nih.gov/pubmed/12137073)

A 58-Year-Old Woman Comes to the Physician Because of a Two-Week