You picked a great example to ask about. The question was closed because of the history. Also, it was a very early question, and on many sites where expectations are redefined, questions (and answers) accepted early on are quite different than newer questions.
In the closed question, the OP made it clear that he disagreed with his doctors and wanted the information to make his case in standing up to ED docs who wanted to use one drug/method above another, one of which he didn't like.
Giving information in order for someone to go against a doctor's advice in a situation as serious as ventricular tachycardia was not a precedent we felt comfortable in setting. The decision to close reflected that in this particular situation, the OP needs to discuss his options with the doctors terminating the rhythm, not get this information from us.
In the second example (the open question), there's no indication that the patient is symptomatic from his low blood pressure. While some of us would be unable to stand up with that BP (87/69), he doesn't present any medical problems with his question. The upvoted answer implies that the patient should modify his BP only if agreed upon whilst consulting with a physician, in other words, treat the patient, not the numbers. (My own BP was 90/60 for the greater part of my adult life, yet I never had a syncopal episode or experienced any limitations whatsoever in my activities. Alas, that number has changed.)
It's not uncommon that users need to post in meta to get a community to reopen a closed question. This is exactly what should be done.
As to what constitutes general medical advice, we're here to answer questions about health, so that's not the problem.
The problem is personal medical advice, e.g. "This is my EKG. My doctor wants me to have a catheterization; I don't want one. Should I have the proceedure?" One definition of personal medical advice is an answer that would help only the OP.
When a question seeking personal medical advice is edited to make it on topic (e.g. here), an answer which would be useful to more people, that's fine.
I agree that it's more on topic now. I've reopened this question.