When the conductor leaves the orchestra, the musicians keep playing from memory for a while. But without a unified rhythm, each one starts to speed up or slow down on their own, and the harmonious symphony turns into disjointed noise. According to new research, the brain and heart behave much the same way in the last hours of a person's life.
Scientists took recordings of electrical activity from the brain and heart — electroencephalograms (brain wave traces) and cardiograms (heartbeat traces)—from patients in the terminal stage. Using a mathematical method that captures signal complexity (multifractal spectrum analysis), they saw that the brain and heart diverge in opposite directions. Brain activity loses its richness of patterns and shrinks to simple, repetitive rhythms, as if all the music were reduced to a single note. The heart, in contrast, begins to produce chaotic, unpredictable fluctuations, like a musician who, in a panic, speeds up the tempo and loses the beat.
The most interesting part is the link between these two processes. When the complexity of brain signals drops, the instability of the heart rises, and vice versa. This suggests that the central regulator, the brain, can no longer restrain and guide the body's work. The periphery, left without control, begins to live its own feverish life. Dying, therefore, turns out to be not a smooth fading but a dramatic severing of connections, where each system moves toward its own finale in its own way.
The heart can keep beating even after the brain has stopped sending signals: it has its own pacemakers. But without brain control, this rhythm becomes wild and unpredictable, like a drummer who has lost the sheet music.