CardioNerds (Drs. Amit Goyal, Matthew Delfiner, and Tiffany Dong) discuss infective endocarditis with distinguished clinician-educator Dr. Michael Cullen. We dive into the nuances of infective endocarditis, including native valve endocarditis, prosthetic valve endocarditis, and right-sided endocarditis.
Notes were drafted by Dr. Tiffany Dong, and audio editing was performed by student Dr. Adriana Mares.
The CardioNerds Beyond the Boards Series was inspired by the Mayo Clinic Cardiovascular Board Review Course and designed in collaboration with the course directors Dr. Amy Pollak, Dr. Jeffrey Geske, and Dr. Michael Cullen.
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Pearls and Quotes
The physical exam is crucial in the evaluation of infective endocarditis and includes cardiac auscultation and a search for sequelae of endocarditis, such as immunologic and embolic phenomena.
The modified Duke Criteria categorizes the diagnosis of infective endocarditis into four different buckets: definite endocarditis by pathology, definite endocarditis by clinical criteria, possible endocarditis, and rejected.
The diagnosis of endocarditis may involve several different imaging modalities, including transthoracic echocardiogram, transesophageal echocardiogram, 4D CT, and nuclear imaging.
For left-sided endocarditis, indications to operate include endocarditis due to S. aureus or fungi, heart failure, evidence of perivalvular complications, persistent bacteremia, and large vegetations.
The management of endocarditis often involves multiple teams, including cardiology, infectious disease, addiction medicine, neurology, anesthesiology, and cardiothoracic surgery.
Notes
What signs/complications of endocarditis are apparent on physical exam and labs?
A new or worsening cardiac murmur with possible signs of volume overload.
Vascular phenomena encompass splinter hemorrhages, conjunctival hemorrhages, Janeway lesions, mycotic aneurysms, and TIA/strokes.
Immunologic phenomena include glomerulonephritis, Roth spots, and Osler nodes.
Positive blood cultures with 2-3 samples collected.
Elevated inflammatory markers.
How does the modified Duke criteria assist in the diagnosis of infective endocarditis?
The modified Duke criteria separate the diagnosis of endocarditis into four categories: definite endocarditis by pathology, definite endocarditis by clinical criteria, possible endocarditis, and rejected endocarditis.
Definitive endocarditis by pathology requires pathologic confirmation of “bugs under the microscope.”
Definitive endocarditis by clinical criteria requires two major criteria, one major and two minor criteria, or all five minor criteria.
Possible endocarditis requires one major and one minor or three minor criteria.
Major criteria:Positive blood culture for typical organism
Evidence of endocardial involvement (e.g., vegetation on echo)
Minor CriteriaPredisposing clinical factors (e.g., intravenous drug use, known valvulopathy)FeverImmunologic phenomenaVascular phenomena
Blood culture for atypical organism
What is the role of TTE compared to TEE in endocarditis?
TTE and TEE both have their roles in the workup for endocarditis.
TTE can provide a baseline screen and yield a better understanding of ventricular size and function than transesophageal.
The strength of TEE is the ability to visualize smaller vegetations along with perivalvular complications that may be missed on TTE.
If clinical suspicion is high for endocarditis, repeat echocardiography is warranted.
What are other tools to evaluate for endocarditis in prosthetic valves?
TTE and TEE remain important and should be commonly utilized for the diagnosis of endocarditis.
