It might just be they they're actually being recognised as being a bit more serious

than just "ill"?

If you've got the Flu, you're ill, someone who is short of breath is ill too. You can be short of breath with the flu.

Chest pains? You can have them with indigestion, could be angina, could be a prelude to a heart attack. You still feel "ill" but exactly how ill are you?

Proper recognition in the first place that it's something different by the sufferer is perhaps a bit easier today? They then put their trust in someone who's supposed to know better?

Even after having an ECG someone could look at it and diagnose one thing. A specialist could diagnose the problem correctly.