Gold medalist Nathan Cohen retires from rowing

London gold medalist Nathan Cohen retires from rowing after heart ailment

WELLINGTON, New Zealand (AP) -- London Olympic gold medalist and two-time world champion Nathan Cohen has retired from rowing after being diagnosed with a serious heart ailment.

Cohen teamed with Joseph Sullivan to win gold in the double sculls at the London games after they had twice combined to win world championships.

But Cohen was diagnosed before this year's world championships, in August, with supraventricular tachycardia, an illness which effects heart rhythm.

He said he began to lose power during races until "it feels like you're dragging something behind the boat."

He missed the world championships and was dropped from New Zealand elite squad.