2025 – PAGE 139 – CARDIOLOGY

PROSTHETIC VALVE ENDOCARDITIS

Treat prosthetic valve endocarditis with IV antibiotics for 6 weeks

• ACUTE: Considered to be within 2 months of the valve being placed. Treat with emergent surgery!
• SUBACUTE: > 2 months since the valve was placed. The most likely etiology is Staph epidermidis, although Staph aureus is also in the differential.
  • If known MRSA or MRSE, give THREE antibiotics (Vancomycin + Gent + Rifampin). The extra medications are for synergy.
  • If known to be regular Staph aureus, use TWO agents: Gentamicin + Cefazolin, Oxacillin, or Nafcillin

PROPHYLAXIS FOR SUBACUTE BACTERIAL ENDOCARDITIS (SBE)

When a cardiac procedure, such as a VSD closure, uses prosthetic “material” (artificial material) for the procedure, the general expectation is that the material will end up being covered with endothelium (become endothelialized) after several months. After that, no prophylaxis is needed to prevent endocarditis in that area. Therefore, such patients generally only get prophylaxis for 6 months. However, when a VALVE is repaired with prosthetic material, endothelialization will not occur in that area. Therefore, such repairs require lifelong prophylaxis. Also, if a repair is done with prosthetic material and a residual defect remains, such as a leak after a VSD repair, then it’s assumed that complete endothelialization will not happen, and therefore prophylaxis should continue. Finally, anyone with a prosthetic valve requires lifelong prophylaxis. With these key points in mind, here are some additional PEARLS!

• ASK THE EXPERT WEBINAR DISCUSSION ON SBE: pbrlinks.com/SBE-CHAT
• MEDICATION: Use Amoxicillin as prophylaxis 1 hour before high-risk procedures, including most dental procedures (including cleanings), respiratory procedures (bronchoscopy), and procedures involving infected skin.
• GI/GU PROCEDURES: Prophylaxis for GI/GU procedures is NOT recommended in those with CHD.
• LIFELONG prophylaxis is indicated if:
  • There is a prior history of endocarditis
  • Any prosthetic valve OR prosthetic material was used for valve repair
  • There is a residual defect after surgical repair of CHD
  • There is unrepaired CYANOTIC CHD (not to be confused with acyanotic CHD like simple ASD’s, VSD’s, etc.).
• SIX MONTHS of prophylaxis is indicated if there are no lifelong prophylaxis indications, but there was placement of ANY prosthetic material in the heart for any reason.

MISCELLANEOUS CARDIOLOGY

PULSUS PARADOXUS

Pulsus paradoxus is defined as a drop in the systolic blood pressure by > 10 mm during inspiration (4–5 is normal) and can happen anytime something compresses the heart. It’s a medical emergency! Seen in:

• Severe Asthma attack
• Myocarditis
• Pericardial Effusion with TAMPONADE

PERICARDITIS

In simple pericarditis, there are no signs of CHF since there is no effusion/tamponade. Findings may include a friction rub, a low-grade fever, muffled heart sounds, and chest pain that is worse when supine, better when sitting up and leaning forward. CXR may show an enlarged heart. EKG may demonstrate ST segment elevations and nonspecific ST changes. The likely causes include a recent viral URI or possibly a rheumatologic issue. Obtain a CXR to look for cardiomegaly and then consider doing an echocardiogram and obtaining fluid for cultures and serologies. Treat with NSAIDS.