Euthanasia is (usually) defined as taking steps to help a person end their life. It can also be choosing not to take steps -- in other words holding back on treatment. This can be done when the health care providers and patient have discussed things, and they all agree that the benefits of treatment with be temporary, or result in a lesser quality of life than the patient wants. Most of the time in this country, terms like "euthanasia" and "assisted suicide" are used to mean the same thing -- depending on which side of the argument a person is on, they might choose to use a different term.
What you describe is not that. I think when you say "reanimation" you mean "resuscitation" -- for instance helping a heart attack patient come back to a stable heart rhythm using drugs and difibrillation. You describe a situation where the resources are scarce or expensive, and are not used for those reasons, not because it's a decision made by, or in cooperation with, the patient. So, in that case, no. That would not be euthanasia. That would just be a lack of resources, or a lack of adequate care.
