platypnea

Etymology
, from and.

Pronunciation
See full workup of the variants at Wikipedia > Shortness of breath > Collation of -pnea transcriptions.

Noun

 * 1)  Shortness of breath that occurs when the patient is upright, that is, sufficient breathing only when lying flat.

Antonyms

 * orthopnea
 * orthopnoea
 * orthopnœa