Heraldo Russell, 72, a retired researcher, lives in London

I wasn’t conscious of a seismic shift in my well being. I used to be simply discovering it tougher and tougher to do the only of issues. I might stroll half a mile and really feel exhausted and wanting breath or climb the steps and be gasping for air.

It was so irritating as I’d at all times been actually match – I used to jog loads and go to the fitness center. However one evening, in 2017, I used to be mendacity in mattress and my respiration felt prefer it was utilizing little pockets of air, fairly than the traditional fluid inhalation, and I felt one thing in my chest go “pop”.

It prompted me to go to the GP, who referred me to a specialist. I used to be instructed that I had a leaky aortic valve and a quickly increasing coronary heart, which was life threatening. It was horrible to listen to – I believed, “oh my god, I’m hanging by a really skinny thread right here; I might have died at any second”.