“The heart is simply a muscle” and first description of the tetralogy of “Fallot”. Early contributions to cardiac anatomy and pathology by bishop and anatomist Niels Stensen (1638–1686)

BackgroundMany are familiar with the parotid duct and the Danish physician/anatomist's name associated with it. However, most are unaware of Niels Stensen's life and his significant contributions to the early study of the heart. For example, he found that the heart is simply muscle and was the first to describe what we now refer to as the tetralogy of Fallot.MethodsA review of germane literature regarding this pioneer of cardiac anatomy was performed.ConclusionsThis physician of the Medici court was clearly ahead of his time and found errors in the publications of such giants as Varolius and Willis. The tetralogy of Fallot should rightfully, be termed the tetralogy of Stensen. The present review discusses the life of this 17th century anatomist, physician and priest/bishop and highlights his contributions to cardiac anatomy and pathology.