questions 5

Endocarditis

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Topic updated on 02/08/17 7:46pm

Snap Shot
  • A 43-year-old man with a history of IV drug abuse reports fever, chills, cough, and pleuritic chest pain for several days. He has an episode of hemoptysis in the ER. Physical exam reveals a temp of 39 degrees Celsius, scattered rales, and a II/VI systolic murmur at the lower left sternal border that increases with inspiration. A lesion is found on the palm of his hand.
Introduction
  • Inflammation of the heart valve, usually secondary to infection
    • usually left-sided
      • unless patient has a history of IV drug use in which case it is usually
        • right-sided due to infected venous blood returning first to the right-heart
        • involving tricuspid valve
  • Types
    • Acute endocarditis
      • associated with fever and rapid degradation of heart tissue
      • caused by
        • Staphylococcus aureus
          • especially in IV drug users
          • can infect healthy or damaged valves (e.g. from mitral valve prolapse or rheumatic heart disease) 
          • mitral valve prolapse is the most common predisposing cardiac condition for infective endocarditis
    • Subacute bacterial endocarditis
      • slower onset of symptoms with less severe symptoms
      • caused by
        • Enterococcus
          • bacteremia most commonly caused by GI/GU interventions
          • growth in 6.5% NaCl differentiates it from S. viridans
        • Streptococcus viridans
          • bacteremia most commonly caused by oral interventions
        • Staphylococcus epidermidis
          • most commonly affects prosthetic valves
        • Streptococcus bovis
          • secondary to ulcerative colitis or colorectal cancer
    • Marantic endocarditis
      • paraneoplastic syndome
        • sterile vegetations on the valves as a result of ↑ coagulability secondary to ↑ mucin production
          • same process underlying Trousseau's sign of malignancy
        • primary cancers in GI tract
        • may produce emboli to periphery
      • note: "marantic" derives from "marasumus" wasting associated with cancer
    • Libman-Sacks endocarditis
      • caused by systemic lupus erythematous (SLE)
        • remember: SLE : LSE
      • usually asymptomatic but mitral regurgitation murmur can be heard
    • HACEK organisms (Hemophilus, Actinobacillus, Cardiobacterium, Eikenella, Kingella)
      • fastidious gram negative organisms
      • suspect with fever + murmur + negative blood cultures
  • Complications
    • chordae tendineae rupture
    • emboli
    • glomerulonephritis
    • suppurative pericarditis
  • Risk factors
    • history of RHD
    • valvular heart disease
    • IV drug use
    • immunosuppression
    • prosthetic heart valve
    • atrial/ventricular septal defect
Presentation
  • Symptoms
    • patients present with range of symptoms that may include
      • high fever that can last for weeks
        • common cause of "fever of unknown origin (FUO)"
      • cough
      • SOB
      • systemic symptoms (weakness, fever, and malaise)
  • Physical exam
    • heart auscultation
      • usually reveals a regurgitation murmur due to valvular damage
    • embolization of vegetations producing immune complex deposition and vasculitis
      • Osler's nodes 
        • small tender nodules on fingers and toes
        • Osler = OUCH
      • Janeway lesions
        • dark, non-tender macules on palms and soles 
      • Roth spots
        • retinal hemorrhage with pale white center
      • subungual petechiae
        • splinter hemorrhages
    • splenomegaly
    • intravascular infection that can spread to other organs 
      • must watch for signs of neurologic, joint, and lung manifestations
    • "FROM JANE" mnemonic
      • Fever, Roth spots, Osler's nodes, murmur, Janeway lesions, anemia, nail hemorrhages, and emboli
Evaluation
  • Diagnosis based on Duke criteria
    • Blood cultures
      • obtain three separated in time and location
      • if multiple positive cultures of the same organism then strong evidence for endocarditis
    • Echocardiography 
      • look for vegetations
      • negative echo does not rule out endocarditits
    • CXR
      • may reveal septic emboli in right-sided endocarditits
Treatment
  • Empiric prolonged antibiotic therapy
  • Surgical valve replacement 


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Qbank (4 Questions)

TAG
(M1.CV.44) A 58-year-old man presents to the doctor with recurring fevers, night sweats and malaise. On exam he is found to have a holosystolic murmur heard loudest over the apex. His dermatologic exam is notable for painless skin lesions shown in Figure 1. Which of the following heart conditions most likely predisposed him to his current condition? Topic Review Topic
FIGURES: A          

1. Bicuspid aortic valve
2. Aortic stenosis
3. Mitral stenosis
4. Mitral valve prolapse
5. Rheumatic heart disease

PREFERRED RESPONSE ▶
TAG
(M1.CV.45) A 32-year-old African American woman presents to her family physician complaining of fevers, fatigue, weight loss, night sweats and a rash on her face that extends over the bridge of her nose. She has no significant past medical history. She denies tobacco, alcohol, and illicit drug use. If she were found to have a cardiac lesion, what would be the most likely pathogenetic cause? Topic Review Topic

1. Bacteremia secondary to a recent dental procedure
2. Abberent flow causing platelet-fibrin thrombus formation secondary to hypercoagulability and maliganncy.
3. Bacteremia secondary to an acute infection from an indwelling catheter
4. Immune complex deposition and subsequent inflammation
5. Left atrial mass causing a ball valve-type outflow obstruction

PREFERRED RESPONSE ▶
TAG
(M1.CV.125) A 35-year-old woman with a medical history significant for asthma, hypertension, and occasional IV drug use comes to the emergency department with fever. On physical exam, there are findings depicted in figure A, for which the patient cannot account. What test will be most helpful to establish the diagnosis? Topic Review Topic
FIGURES: A          

1. Echocardiography
2. Chest X-ray
3. Pulmonary function tests
4. Electrocardiogram (EKG)
5. CT pulmonary angiography

PREFERRED RESPONSE ▶
TAG
(M1.CV.134) A 25-year-old man presents to the emergency room with shortness of breath. He has no past medical history and takes no medications. On physical exam, vital signs are temperature 38.1° C, heart rate 110/min, blood pressure 118/76 mm Hg, respiratory rate 22/min, and oxygen saturation 98% on room air. He appears malnourished and has poor dentition. Physical exam also reveals the markings along the cubital fossa as shown in Figure A and a low frequency pansystolic murmur best heard on the lower left sternal border. The murmur increases with inspiration and decreases with expiration and Valsalva maneuver. The patient is treated for his illness but later presents with hematuria, hypertension, and an elevated creatinine. What is the most likely cause of this patient's subsequent renal disease? Topic Review Topic
FIGURES: A          

1. Dilation and blunting of the renal calyces with cortical thinning
2. Immune complex deposition
3. Vascular damage to renal vessels secondary to benign nephrosclerosis
4. Hereditary nephritis caused by a mutation in glomerular basement membrane
5. Renal papillary necrosis secondary to infarctions of the medulla

PREFERRED RESPONSE ▶
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