how does this grammar function? ~다면서요?
Here's an example: 환자가 응급실에서 죽었다면서요?

I heard that the patient passed away at the emergency room?

Question

how does this grammar function? ~다면서요?
Here's an example: 환자가 응급실에서 죽었다면서요?

I heard that the patient passed away at the emergency room?

Answer

It's equivalent to "I heard that...." and you're asking if it is true/correct.

Adj / (Verb + ㄴ/는) + 다면서요

e.g.
아팠다면서요? = I heard you were hurt (is it true?)
전화 한다면서요? = I thought you said you will call (is it true?)
하교에 갔었다면서요? = I heard you went to school (is it true?)

You can drop the 요 for informal speech.

Answer

I've heard that~~ 
people says that ~~

it's utilised when we borrow other's words.

Answer

If you say ~다면서요?, you mean you ask someone again something you have heard.