It suddenly started when I was around 45.
I've heard that happen to few people. Or atrial fibrillation suddenly starting. The risks increase as you get older.
I've had a lot of stress the past few years and have an autoimmune disease. I don't know if it's a reaction to medications I'm on, the stress or who knows what?
Heart problems don't run in my family on either side.
On the plus side - so far- mine seems completely postural. It only happens sometimes if I am bending down, but mostly when I lie down to go to sleep. My stomach needs to be completely empty to have any hope of not triggering it. Good for the diet!
My heart is normal according to MRI. I have lowish blood pressure and a good heart rate. They asked me if I'd been an athlete in my younger days (hahahah what a joke!). Turns out my smallish and troubled lungs have made my heart work overtime for years so it's as fit as a fiddle.
Confusing picture 