Long QT syndrome

Question 1

Long QT syndrome (LQTS) is an inherited condition associated with delayed

Answer 1

repolarization of the ventricles

Question 2

delayed depolarisation of ventricles occur due to

Answer 2

loss of function/ blockage of potassium channels

Question 3

congenital cause of long QT ?

Answer 3

Jervell-Lange-Nielsen syndrome (includes deafness and is due to an abnormal potassium channel)

Romano-Ward syndrome (no deafness)

Question 4

drugs prolonging QT ?

Answer 4

amiodarone,
sotalol, class 1a antiarrhythmic drugs
tricyclic antidepressants,
selective serotonin reuptake inhibitors (especially citalopram)
methadone
chloroquine
terfenadine**
erythromycin
haloperidol
ondanestron

Question 5

electrolyte abnormalities with prolonged QT ?

Answer 5

hypocalcaemia,
hypokalaemia,
hypomagnesaemia

Question 6

cardiac causes of prolonged QT ?

Answer 6

acute myocardial infarction
myocarditis
hypothermia
subarachnoid haemorrhage