title: Ibutilide-induced long QT syndrome and torsade de pointes.
abstract: Ibutilide is a class III antiarrhythmic agent used for the termination of atrial fibrillation and atrial flutter. It mainly affects membrane potassium currents and prolongs the cardiac action potential. This effect is reflected as QT interval prolongation on the surface electrocardiogram. Like other drugs that affect potassium currents, ibutilide is prone to induce a malignant ventricular tachycardia, torsade de pointes. We report four cases of torsade de pointes after administration of ibutilide for pharmacologic cardioversion of atrial fibrillation and atrial flutter; three of these cases required direct current cardioversion for termination of torsade de pointes. All four patients were female. We discuss the risk factors for development of ibutilide-induced torsade de pointes.
authors.affiliation: Division of Cardiology, Long Island College Hospital, Brooklyn, NY, USA.
authors.forename: Ramesh M
authors.initials: RM
authors.lastname: Gowda
authors.forename: Gopikrishna
authors.initials: G
authors.lastname: Punukollu
authors.forename: Ijaz A
authors.initials: IA
authors.lastname: Khan
authors.forename: Raghotham R
authors.initials: RR
authors.lastname: Patlola
authors.forename: Furqan H
authors.initials: FH
authors.lastname: Tejani
authors.forename: Braulio F
authors.initials: BF
authors.lastname: Cosme-Thormann
authors.forename: Balendu C
authors.initials: BC
authors.lastname: Vasavada
authors.forename: Terrence J
authors.initials: TJ
authors.lastname: Sacchi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000889:Anti-Arrhythmia Agents / Q000009:adverse effects*; D004554:Electric Countershock; D005260:Female; D006801:Humans; D008133:Long QT Syndrome / Q000139:chemically induced*; D008875:Middle Aged; D013449:Sulfonamides / Q000009:adverse effects*; D016171:Torsades de Pointes / Q000139:chemically induced*
chemical_list: D000889:Anti-Arrhythmia Agents; D013449:Sulfonamides; C067192:ibutilide