It was the summer of 2011 and life was good. In anticipation of a late-season cycling trip to the Dolomites, I’d been steadily building fitness since January. One Saturday, bored of my local Cotswold rides, I drove down through Devon to run the spectacularly pretty but brutally hilly 24km Sidmouth to Beer coastal path. Despite the 2,000m of ascent, I remember gliding effortlessly along the cliff-tops that day with just the gulls for company, wheeling above me in a brilliant blue sky.
Back in Sidmouth, lounging in a cafe, I became aware of a strange sensation in my chest. It was as if an agitated finch was trapped in my upper ribcage. Still wearing my heart rate monitor, I watched my heart rate yo-yo between 70bpm and 280bpm. I ran 50m up the beach hoping it would reset. It didn’t. In fact, I was now feeling positively unusual. Fearing the worst, I walked back to the café and asked the waiter to call an ambulance. Two hours later I was lying in a hospital bed in Exeter, encircled by junior doctors taking turns to peer at me, then at the folds of
