Traditionally , vegetations are sine qua- non for diagnosing Infective endocarditis.
The following are major criteria to diagnose IE
- Evidence for endocardial involvement in the form of visible vegetation or New onset regurgitant murmur.
- Positive blood culture
There are six minor criteria .
To diagnose IE we need
- Two major or
- One major and 3 minor or
- 5 minor criteria alone
Now ,we realise IE do occur in the absence of visible vegetation.This happens because, vegetation can appear late, it is too small and missed , burroughs inside tissue plane instead of entering cavity , may form micro abscess or vegetation growth is prevented by prompt empirical antibiotics.
Final message
Vegetation is still a prime sign to diagnosis of IE. However , please do not insist on it .There can be significant endocardial infection without formation of vegetation.The current criteria allows us to make a diagnosis of IE without documenting a clear cut visible vegetation.
Dr.S.Venkatesan MD 