Feeling tired

Hi all, some of you may have seen my previous post. I have been diagnosed with Brugada's syndrome and Prinzmetals angina. Had an ICD fitted 9 days ago but am feeling very tired still. Is this normal. Had to spend 5 hours in hospital on Wednesday as I had severe chest pains but the results showed that I had not had a heart attack. This followed some gentle walking, so is atypical of Prinzmetals. Has anyone else experienced this. Thanks. Pete.