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