Seeing the Heart's Flicker in Two Mirrors at Once
The heart doesn't beat like a metronome but like a jazz drummer: sometimes it stumbles, skips beats, or races. Atrial fibrillation is one of the most insidious glitches: the atria quiver instead of contracting, and blood can pool, forming clots. Doctors catch this glitch on an ECG — a recording of the heart's electrical signals.