This poem is written in pretty free free verse, so there's no rhyme or meter to keep it chugging along. There's almost no punctuation in the poem either, so reading it out loud might make you lose your breath. It certainly sounds like the speaker has lost his!
The only moments of punctuation in the poem are the exclamation points in the lines that tell us "Lana Turner has collapsed!" While the rest of the poem moves pretty quickly and mimics the speaker trotting along the city street, the exclamation points make us pause and add emphasis to these lines. And when O'Hara capitalizes "LANA TURNER HAS COLLAPSED!" you might get the feeling that he is yelling. Go with this feeling. Climb to your rooftop and yell: LANA TURNER HAS COLLAPSED! It will feel good – we promise.