Atrial fibrillation, on Coumadin.
 Patient has NSR
(ROOT (FRAG (NP (JJ Atrial) (NN fibrillation)) (, ,) (PP (IN on) (NP (NNP Coumadin))) (. .)))
(ROOT (S (NP (NN Patient)) (VP (VBZ has) (NP (NN NSR)))))
( ( Atrial fibrillation ) ( , ( ( on Coumadin ) . ) ) )
( Patient ( has NSR ) )