The prolonged QTc syndrome may be associated with a number of conditions. The risk for the patient increases when more than one condition is present.
Genetic causes include:
(1) Jervell and Lange-Nielsen Syndrome
(2) Timothy syndrome
(3) Andersen-Tawil syndrome
(4) Brugada syndrome
Acquired causes:
(1) electrolye abnormalities (hypocalcemia, hypokalemia, hypomagnesemia)
(2) malnutrition (including anorexia nervosa, refeeding syndrome)
(3) drugs
(4) cardiac disease (myocarditis, acute myocardial ischemia, cardiomyopathy)
(5) central nervous system disease (subarachnoid hemorrhage, other)
(6) autonomic nervous system dysfunction
