Abstract
A 46-year-old female treated with typical antipsychotic drugs for schizophrenia was transported by ambulance to the emergency department (ED) due to altered mental status. Her mental status was Glasgow Coma Scale score of 7 on arrival and the blood chemistry examination revealed severe hyponatremia (101.5mEq/l). Hypertonic saline was infused for the correction of hyponatremia. After the insertion of a Foley catheter in ED, copious diluted urine (total 9800 ml) was collected. Two hours after arrival, QT interval was further prolonged to 620 msec. Incessant PVCs were observed and developed to polymorphic ventricular tachycardia of torsade de pointes (TdP), leading to ventricular fibrillation (VF). Resuscitation was performed, and VF and TdP were terminated successfully with cardiac defibrillation and magnesium sulphate infusion. Additional predisposing factors for cardiac arrhythmia were electrolyte loss in urine with subsequent hypocalcemia, hypokalemia and hypomagnesemia. The QT interval was normalized on the fourth hospital day with the correction of electrolytes imbalance and cessation of typical antipsychotic drugs. The present case may alert emergency physicians for the development of TdP/VF during the treatment of water intoxication with concomitant drug-induced QT prolongation and electrolyte imbalance.
