New Murmur and Fever After Dental Work
A 45-year-old man presents with 10 days of fever, night sweats, and fatigue, and a new heart murmur noticed by his dentist 2 weeks after a dental extraction. He has a history of a bicuspid aortic valve diagnosed in childhood. Vitals: temperature 38.6 °C, BP 128/70 mmHg, HR 98/min. Exam: early diastolic decrescendo murmur at the left upper sternal border, bounding pulses, and splinter hemorrhages on the nail beds. Labs: leukocytosis, elevated CRP, creatinine 1.1 mg/dL. Blood cultures have been drawn but results are pending. ECG shows sinus tachycardia without conduction delay.
1. What is the most likely diagnosis and how would you confirm it and begin treatment?
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The presentation is infective endocarditis of the aortic valve in a patient with a bicuspid valve and recent dental procedure. Supporting features: fever, new regurgitant diastolic murmur, peripheral stigmata, and elevated inflammatory markers. The bicuspid valve is a predisposing lesion.
Confirmation and treatment:
- Obtain at least three sets of blood cultures from separate sites before antibiotics; if cultures are already drawn, do not delay antibiotics in an unstable or septic patient, but coordinate with microbiology.
- Transthoracic echocardiography first; if negative or nondiagnostic, transesophageal echocardiography to look for vegetations, abscess, or valve destruction.
- Start empiric IV antibiotics covering staphylococci, streptococci, and enterococci per local protocol, then tailor to culture results.
- Monitor for heart failure, embolic events, and conduction abnormalities; obtain a surgical consult if there is severe regurgitation, abscess, or persistent infection.
Do not attribute the murmur to a benign flow murmur without echocardiography.
2. What complications would you monitor for, and when would surgery be indicated?
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Complications to monitor:
- Heart failure from acute aortic regurgitation - watch for dyspnea, pulmonary edema, and worsening hemodynamics.
- Embolic events - stroke, splenic or renal infarcts, mycotic aneurysm.
- Perivalvular abscess or fistula - new conduction delay, persistent fever, or recurrent bacteremia.
- Sepsis and renal dysfunction.
Surgery is indicated for: severe aortic regurgitation with heart failure, valve obstruction, perivalvular abscess or fistula, persistent bacteremia despite appropriate antibiotics, large mobile vegetations with high embolic risk, or fungal/resistant organisms. Timing is urgent when hemodynamics deteriorate.
Escalate to cardiology and cardiac surgery early, and involve infectious disease for antibiotic duration and follow-up cultures.