Table 1.

Causes of acquired long QT syndrome.

1. Drugs

-Antiarrhythmic drugs (class I and class III)

-Antimicrobials (fluoroquinolones, macrolides, imidazole antifungals, antimalarials, HIV protease inhibitors)

-Antihistamines (histamine H1-receptor antagonists)

-Psychoactive agents (antidepressants, antipsychotics, lithium, methadone)

-Motility and antiemetic drugs (cisapride, domperidone, serotonin 5-HT3-receptor antagonists)

-Anticancer drugs (arsenic trioxide, tamoxifen)

-Diuretics (indapamide)

-Inotropics (phosphodiesterase III inhibitors)

-Immunosuppressants (tacrolimus)

2. Electrolyte imbalances

-Hypokalemia, hypocalcemia, hypomagnesemia

3. Structural heart diseases

-Ischemic heart disease, left ventricular hypertrophy, heart failure, Takotsubo cardiomyopathy

4. Bradyarrhythmias

-Complete atrioventricular block (or any bradyarrhythmia, even transient)

5. Endocrine disorders

-Hypothyroidism, corticosteroid insufficiency, diabetes mellitus, pheocrhromocytoma

6. Inflammatory diseases

-Inflammatory heart diseases (myocarditis, Chagas’s disease, rheumatic heart disease)

-Systemic inflammatory diseases (rheumatoid arthritis, connective tissue diseases)

7. Autoimmunity

-Anti-Ro/SSA antibodies

-Other autoantibodies (anti−β1-adrenergic receptor, anti-Kv1.4 potassium channel)

8. End-stage liver disease

9. Nervous system injuries

-Subarachnoid hemorrhage, thalamic hematoma, right neck dissection, autonomic neuropathy

10. HIV infection

11. Starvation

-Anorexia nervosa, “liquid protein” diets, gastroplasty and ileojejunal bypass, celiac disease

12. Hypothermia

13. Toxins

-Cocaine, arsenic, organophosphates (insecticides, nerve gas)