Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
breathless [ˈbrɛθlɪs] adj (from exertion) запыха́вшийся; (after illness) с затруднённым дыха́нием
he was breathless with excitement у него́ перехвати́ло дыха́ние от волне́ния
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: