Husband passed out several times. Doctors can’t find cause.

Hi All, I am new to this page, to be honest I’ve been reading so much on a lot of different conditions in the hope of being able to help my husband. On 2nd January my husband (39M) passed out, it was terrifying. He felt sick/clammy then was out. I phoned an ambulance & after a week in hospital & ECG’s, Bloods, Monitoring etc - he was told he had low blood pressure but that’s not uncommon as he is fit & active. They couldn’t find a reason this happened from the tests. He’s since been discharged while we wait for an appointment to have a loop fitted. Since then, he’s passed out twice. I have raised his legs until he comes to at which point he is a bit confused for a few seconds. I suppose I just wanted to hear if other people have experienced this? It’s scary not knowing whats happening & waiting for the loop appointment. I wanted to phone an ambulance when it happened again, but when he came to he refused.