This issue has to be discussed on a case-by-case basis. For example, transient ischaemia, transient myocardial ischaemia, such as stable angina, is possible with transient closure insufficiency, in which case mitral valve closure insufficiency due to papillary muscle ischaemia is not severe. However, if the patient has papillary muscle necrosis as a result of an acute myocardial infarction, then permanent mitral valve closure insufficiency will result at this point and the situation will be very serious.