Chinese wuxia (and derivative Western) fiction describes the touch of death, a single blow that can kill an opponent. Surprisingly, this is actually possible.
Wuxia is a genre of Chinese novels, comics, games, television shows, and films set in a fantasy version of ancient China. The most common form is that of martial artists walking the land, fighting, righting wrongs, and (suspiciously often) avenging the death of their master. To Western audiences the most familiar wuxia is probably the film Crouching Tiger, Hidden Dragon, but the genre has been around for centuries.
One of the core elements of wuxia is dianxue. This is the ability to attack opponents by hitting acupuncture pressure points on their body – strike in the right place and you can stun, paralyse, or even kill them. The touch of death, the ability to kill someone with a single hit, has been adopted wholeheartedly by Western pop culture. If you’ve seen Kill Bill Part 2 you know what I’m talking about here. However, and this may come as a surprise, the touch of death is actually possible – and several people die every year because of it.
When you see a heartbeat on an electrocardiogram, you’re seeing a specific rhythm that describes just how the various parts of the heart are polarising and depolarising (which in turn control how the heart pushes blood through itself). For most of us, that’s the standard sinus rhythm – that classic heartbeat shape. But if you have heart troubles the electrocardiogram will show various arrhythmias. Some of these irregular rhythms aren’t super-serious, but if your heart gets into a bad rhythm then death can follow soon after.
If your chest is hit in exactly the right place at exactly the right time, a normal cardiac rhythm can be pushed into a lethal one almost instantly. The right place? On the left side of the body, between the second and fourth ribs from the top. The right time? At a point in the heart rhythm called the T wave, the point at which the ventricles are repolarising. On an electrocardiogram, it’s the last upwards bump in the rhythm:
A strike in that place at that time can send your heart into ventricular fibrillation. On a monitor this looks like a chaotic mess; inside the body, the heart muscles are twitching and flexing, but are not coordinated and definitely not pumping blood. It’s usually fatal.
And yes, this condition – its formal name is commotio cordis – happens in real life. No, a secret cadre of lethal martial artists are not roaming the Earth (that I know of). Getting the timing right (within a few milliseconds) is near-impossible. Instead, commotio cordis happens accidentally during sporting events: people are hit by a baseball or football, or are punched or kicked at just the wrong time, and they drop dead. It’s rare but kills a few people every year.