Atrial fibrillation, on Coumadin.
 Patient had elevated INR
(ROOT (FRAG (NP (JJ Atrial) (NN fibrillation)) (, ,) (PP (IN on) (NP (NNP Coumadin))) (. .)))
(ROOT (S (NP (NN Patient)) (VP (VBD had) (NP (JJ elevated) (NN INR)))))
( ( Atrial fibrillation ) ( , ( ( on Coumadin ) . ) ) )
( Patient ( had ( elevated INR ) ) )