In the early 1900s, Willem Einthoven developed the string galvanometer into the first practical electrocardiograph. The ECG allowed physicians to record the heart's electrical activity with unprecedented accuracy. It became fundamental to diagnosing rhythm disorders, heart attacks and conditions requiring anticoagulation.

The ECG made the heartbeat visible as a written trace, almost a poem of electrical rhythm. Its jagged line entered visual culture as a sign of life, crisis and the measurable pulse beneath human emotion, inspiring poets to explore themes of life, death, and the human experience in their works.