Acute symptomatic hyponatremia complicating invasive cardiac procedures: a report of three patients.

Hyponatremic encephalopathy is a well-known complication of surgical procedures. This syndrome has not been described in the cardiology literature. We report three patients who developed acute hyponatremia with life-threatening encephalopathy following an invasive cardiac procedure. Diagnosis and treatment were delayed because of a lack of awareness for the syndrome among the cardiology staff. The diagnosis of hyponatremia should be suspected in any patient who develops behavioral or neurological manifestations following an invasive cardiac procedure. Prompt diagnosis and treatment are essential to avoid permanent neurological damage or death.