My local GP was near by so I went there first, described what was happening to the receptionist... they said 'Call 111' (NHS non-emergency triage, for non-Brits) and shoo'd me off; I loitered around and Googled symptoms and yea... 'possible heart attack, go to A&E NOW' was the general gist. Called 111 from within view of the receptionist in case I collapsed, 15 minutes later I'm still on hold - I figured all they'd do would put me through to 999 after spending 10 mins asking questions.
Got an Uber to A&E, and had an EKG within about 20 minutes of arriving. They said it's not a heart attack, probably isn't myocarditis or pericarditis, then the weird question 'do you suffer from anxiety or any mental health problems?'...
I'm 100% sure it wasn't psychosomatic or an anxiety attack. But that was the point where their concern ended and I was discharged with no follow up from GP or any idea of what had happened. Turns out, it was acute pancreatitis caused by a gall stone - I had to pay privately to find that out because repeated GP appointments they couldn't care less.
Either way, it's an absolute clusterfuck, and this same pattern of systemic dysfunction has been repeated with pretty much every interaction I've had with NHS funded services (both hospitals and GPs), and I'm fairly sure - like in a_c's friends case - if it had've been a heart attack it would've required me to drop dead in the GPs reception for them to do anything more than just pass the buck.