Torsades de pointes in 3 patients with leukemia treated with arsenic trioxide

Arsenic trioxide is used in clinical trials in the treatment of relapsed an d resistant cases of acute promyelocytic leukemia. Adverse effects from ars enic in these studies have been multisystemic. Arsenic is known to cause co rrected QT-interval prolongation and T-wave changes, but the potential for serious ventricular arrhythmias is less well understood. Torsades de pointe s, a form of ventricular tachycardia, has been reported with arsenic poison ing but not at therapeutic doses used in protocols for hematologic malignan cies. We describe 3 patients in whom this arrhythmia developed while they w ere treated with arsenic trioxide. Early recognition of the arrhythmia or c orrection of contributory factors is important because arsenic induced vent ricular arrhythmias are known to be resistant to most chemical methods and electrical cardioversion. (Blood, 2001; 97:1514-1516) (C) 2001 by The Ameri can Society of Hematology.