Systemic hemodynamics during cough induced and vasovagal syncope

Common faint and the so-called situational syncope are usually listed together in the category of “neurally mediated syncope”. Although vasovagal syncope has been subject of extensive research in the past years, its mechanism is not fully understood. Much less information is available about situational syncope. Numerous entities in this heterogeneous group are related to excessive straining (e.g. weight lifter's or trumpet player's syncope). Cough syncope is also associated with tremendous intrathoracic, intravascular, and even intracranial pressure fluctuations. Although reflex responses are certainly triggered during cough, their relative role, and their analogy with the classical vasovagal reaction are not clear. We report a case of vasovagal syncope and cough reaction occurring in the same subject during laboratory testing.