“One dark morning last May, I wrecked my body giving 10 minutes of CPR. My 34-year-old husband, Will, had been lying peacefully next to me, both of us fast asleep. I woke up suddenly to a loud noise I will never forget.

At first, I thought he was snoring. I groggily nudged him, but he just continued making the horrible sound. I shook his shoulder, but he didn’t respond. As reality set in, I realized that the sound had an urgent, panicked quality to it. It wasn’t rhythmic or soft. His torso didn’t gently rise and fall as I had watched it move so many times before. I had never heard of agonal breathing.”