Do it one more time but be calm. No worry it's just a medical test.
In my view and conversations with the medics on the panel, hypertension itself is not an issue. Its not a drain on Canada's resources to treat you for hypertnesion (if that is the case).
The issue is if hypertension has gone untreated for some time and has led to complications, e.g. damage to your heart or other organs, which would require costly treatment in Canada, e.g. an organ transplant. This is the issue of concern, when the medical cost to Canada will be on the high end of the spectrum. In this scenario, they can disqualify you on medical grounds.
So dont worry about the hypertension on its own. Its the complications that, if they exist, will bar you from entry.
(and even in that scenario, there are immigration lawyers who can take on the case and increase your chances. I stumbled on to one guys website and he has had success with getting PR for people with serious and expensive medical conditions).