A patient meets Duke criteria for definite infective endocarditis. Echocardiography shows severe aortic regurgitation with a 12 mm vegetation and new PR interval prolongation on ECG. What does the PR prolongation signify and what action should be taken?
- A Drug toxicity from aminoglycosides; stop gentamicin
- B Perivalvular extension with aortic root abscess; urgent surgical consultation ✓
- C High vagal tone in sepsis; atropine and observe
- D Ischaemic AV node disease; temporary pacing
Correct answer: B. Perivalvular extension with aortic root abscess; urgent surgical consultation
Explanation
New or progressive PR prolongation (first-degree or higher AV block) in aortic valve endocarditis is a sign of perivalvular extension and abscess formation involving the aortic root and the adjacent AV node/His bundle. This is an absolute surgical indication. Aortic root abscess is confirmed by TEE (sensitivity >85%) and requires emergency surgery. Mortality with perivalvular abscess is high without surgery. Aminoglycoside toxicity causes renal impairment and ototoxicity, not PR prolongation.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.