Prolonged QT

METABOLIC ABNORMALITIES
  • Hypokalemia
  • Hypocalcemia
  • Hypomagnesemia
  • Alkalosis
  • Liver failure
DRUG EFFECTS
  • Antiarrhythmics (potassium-channel blockers):
    • quinidine, procainamide, disopyramide, sotalol, amiodarone, dofetilide, ibutilide
  • Psychotropic agents (phenothiazines, haloperidol, TCAs, SSRIs)
  • Antibiotics (microlides, quinolones, azoles)
  • Antihistamines
  • Cocaine
  • Many others, especially in combination
ACUTE CNS DISORDERS
  • Subarachnoid hemorrhage
  • CVA, especially thalamic stroke
  • Brain tumor
  • Closed head injury
  • Status epilepticus
ACUTE MYOCARDIAL INJURY AND/OR CATECHOLAMINE EFFECT
  • Ischemia
  • Pulmonary edema (usually ~24 hrs after resolution)
  • Stress-induced cardiomyopathy (including Tako-Tsubo syndrome)
  • Massive PE
  • Adrenergic agonists (inotropes, inhalers)
  • Pheochromocytoma
  • Cocaine
​CONGENITAL LONG QT SYNDROME