Edward P. Sharpey-Schafer was right: evidence for systemic vasodilatation as a mechanism of hypotension in cough syncope.

Cough syncope typically occurs in middle aged and senior, muscularly built males with a history of chronic obstructive lung disease. Originally, cough syncope was thought to be a form of epilepsy and only in the 1940s it was recognized to be of syncopal nature. The circulatory pathophysiology is, however, still not fully understood. We present data on two cough syncope patients in whom we documented the beat-to-beat changes in cardiac output and total peripheral resistance during cough syncope using pulse wave analysis. Our results give support to Edward P. Sharpey-Schafer's hypothesis that a decrease of total peripheral resistance plays a pivotal role in the pathophysiology of cough syncope. Systematic studies are needed to confirm this mechanism in larger series of patients.