Last night, he began having chest pain at rest.
 patient has an acute MI
(ROOT (S (NP (JJ Last) (NN night)) (, ,) (NP (PRP he)) (VP (VBD began) (S (VP (VBG having) (NP (NN chest) (NN pain)) (PP (IN at) (NP (NN rest)))))) (. .)))
(ROOT (S (NP (NN patient)) (VP (VBZ has) (NP (DT an) (JJ acute) (NNP MI)))))
( ( Last night ) ( , ( he ( ( began ( ( having ( chest pain ) ) ( at rest ) ) ) . ) ) ) )
( patient ( has ( an ( acute MI ) ) ) )