When Damar Hamlin collapsed on a football field from a frightening but fascinating medical event called “commotio cordis” (disrupted heart), the name alone sent me off to read about it in Wikipedia.
I was fascinated to learn that the “window of vulnerability” is tiny, occurring during only 1–3% of the total heartbeat cycle, when the left ventricle is “repolarizing,” getting ready to go from systole to diastole, at the trailing edge of the last heartbeat. This delicate moment is when a heart, particularly a young heart, can, if thumped the wrong way, be sent into a paroxysm of arrhythmia and stop functioning as a highly coordinated pump. A ball or body part delivering, at that balancing moment, just enough force to the exact right location — left of the sternum, between the second and fourth ribs — deals a disorganizing death blow to the heart.
No one could read such a description without thinking of his own heart, and my attention was drawn to mine, which has been beating reliably for the better part of seven decades. I don’t often think about my chest, but focusing on that area brought back a long lost memory:
I’m a young boy, maybe in the 10–12 range. And I notice that my lowest ribs stick out at an angle. My chest could be a sort of ski jump; if you went hurtling down my ribs, the last one would launch you off into space, and you’d have an…
