CAUSES:
- CONGENITAL :
* ROMANO WARD SYNDROME( AUTOSOMAL DOMINANT)
* JERVELL LANGE-NIELSON SYNDROME
( AUTOSOMAL RECESSIVE
- ACQUIRED : DRUG INDUCED
* ANTIARRHYTHMICS - QUINIDINE, PROCAINAMIDE, DISOPYRAMIDE, FLECAINIDE, PROPAFENONE, SOTALOL, IBUTILIDE, DOFETILIDE, AMIODARONE
* ANTIMICROBIALS - ERYTHROMYCIN, CLARITHROMYCIN, TRIMETHOPRIM, KETOCONAZOLE, ITRACONAZOLE, CHLOROQUINE
* ANTIHISTAMINES - TERFENADINE
* OTHER DRUGS - AMITRIPTYLINE, FLUVOXAMINE, CHLORPROMAZINE, DOMPERIDONE, CISAPRIDE, GLIBENCLAMIDE
* ELECTROLYTE IMBALANCE - HYPOKALEMIA, HYPOMAGNESEMIA, HYPOCALCEMIA
* SEVERE BRADYCARDIA - COMPLETE HEART BLOCK, SINO ATRIAL NODE DISEASE, HYPOTHYROIDISM, HYPOTHERMIA