No, the history of heart rate variability traces back to the Ancient Greeks who were the first to notice that the heartbeat changes. The Greek physician Galen wrote 18 papers on the heart rate, analyzing it to diagnose patients and predict how well they would cope with an illness.
German physician Carl Ludwig was the first to actually measure variability in 1847. He studied heart rate in dogs, noting that it speeds up on the inhale and slows down with the exhale.