• QT prolongation can be seen in hereditary long QT syndrome (a channelopathy) and acquired long QT syndrome.
• Causes of acquired long QT syndrome include:
Drug-induced:
Antiarrhythmics (class I, III)
Antidepressants (TCA)
Antipsychotics
Antihistamines
Antiemetics
Antimicrobials (macrolides, -azoles)
Methadone
Metabolic:
Hypokalemia
Hypocalcemia
Hypomagnesemia
Other:
Intracranial hemorrhage
• It is important to identify prolonged QTc early to prevent progression to Torsades de pointes and fatal tachyarrhythmia.
