Autonomic dysfunction in end-stage liver disease manifested as defecation syncope: Impact of orthotopic liver transplantation

Patients with end-stage liver disease (ESLD) may be at increased risk for s yncopal episodes based on their circulatory physiological state, Although a definitive cause for this is not known, several mechanisms have been propo sed. In patients with ESLD, defecation syncope may result from a failure of short-term neurocirculatory adaptation to the Valsalva maneuver in the fac e of a hyperdynamic circulatory state and a decreased effective intravascul ar volume. We describe 2 patients with ESLD who had repeated episodes of de fecation syncope before orthotopic liver transplantation (OLT), The most ef fective treatment of these syn-copal episodes appears to be fluid administr ation and the use of a pressor agent, such as dopamine, to help maintain bo th an effective heart rate and intravascular volume. Correction of this alt ered circulatory physiological state through OLT prevented further syncopal episodes in both patients. A search of the literature failed to show previ ous reports associating ESLD and defecation syncope, Possible mechanisms fa voring this association are reviewed. Copyright (C) 1999 by the American As sociation for the Study of Liver Diseases.