Memory difficulties are one of the most common and distressing effects of cardiac arrest, and they are a normal consequence of how cardiac arrest affects the brain.
During cardiac arrest, the brain is deprived of oxygen. The hippocampus — the brain structure most important for forming and retaining new memories — is particularly vulnerable to oxygen deprivation. Even a relatively brief period of hypoxia can result in lasting changes to memory function.
Common memory difficulties after cardiac arrest include trouble retaining new information, forgetting things shortly after being told them, losing track of conversations, difficulty remembering names, and problems with prospective memory (remembering to do things). Some survivors also have a gap in memory around the time of the arrest itself — they have no recollection of collapsing or of their time in ICU. This memory gap is normal and is not the same as ongoing memory impairment.
The good news is that memory often improves significantly over the first year of recovery, as the brain heals and adapts. Strategies such as writing things down, using calendars and reminders, reducing cognitive load, and being patient with yourself can all help in the meantime.
If memory difficulties are significantly affecting your daily life or your ability to work, ask your GP for a referral to a neuropsychologist or cognitive rehabilitation service.