Should the days of not fasting in Ramadan due to menstruation be made up, or is expiation sufficient, given the suffering from cardiac electricity that increases with fasting?

You are obligated to make up the days you missed, as much as you are able, even if in the short winter days and not consecutively. Expiation (kaffarah (definition)) is not sufficient for you, as it is for one who is unable to fast and whose inability is not expected to cease. You are also required to pay a fidyah (definition) for delaying the make-up, unless you were unaware of the ruling.