Edmund Goodwyn and the first description of diving bradycardia.

Diving bradycardia is a primordial oxygen-conserving reflex by which the heart rate of air-breathing vertebrates, including humans, slows down in response to water immersion. Its discovery is attributed to Paul Bert, whose seminal observation was published in 1870 as part of a series of experiments that examined physiological adaptations to asphyxia in ducks and other animals. However, Edmund Goodwyn, a British physician who studied medicine at the University of Edinburgh, had already described this reflex in his doctoral thesis, which was originally published in Latin in 1786 and again in English in 1788. Ironically, even though Goodwyn's work has yet to be recognized in the diving physiology literature, it was referenced in the very publication that contains Bert's original observation. Thus this article brings Goodwyn's work and its historical context to light and argues that he should be credited with the first description of diving bradycardia.