It is interesting that she had cardiac surgery as an infant. It does remind me of the situation of an acquaintance where the patient had cardiac problems as an infant/toddler that were fixed and then essentially moved on until they suddenly dropped dead (while apparently fit and healthy) in their early twenties. One one hand you'd think gee, maybe if you had such a rough start they would follow you up with a super-duper checkup every few years or so. On the other hand, I guess when the invincibility of youth sets in, no apparently healthy person wants to go to the doctor and relive their past.
Edit: sorry - s/she/you, didn't realise the HN comment was by the original author.
I have had cardiac check-ups at least once a year for my whole life. In several instances, new problems were found at one of the check-ups and the wheels were set in motion to mend things. Further, when I was in hospital for the cardiac arrest, the bulge in my aorta was discovered by accident.
I live in the UK. Perhaps the NHS are more will to keep tabs on people than private health services in other countries.
It's customary to end an anecdote like this with a short "morsel of wisdom" summarising the above but shit, what can you say to that. Go to the doctor, folks. Checkup once every 2 years. Could save your life.