Cardiomyopathy. That is variable so no time can be put on that also not all cardiomyopathies are reversible.
That varies. It depends on exactly what you mean. With medication, there can be improvement quickly. Most of the time there is not a cure, but the symptoms can be controlled. In certain unusual cases, the problem can completely resolve so that the problem does "correct itself." that usually occurs over a period of many weeks or months. It is a gradual process. Cardiomyopathy related to pregnancy can resolve.