Table 1

Electrocardiographic features assessed in children with LQTS and HCM

LQTSHCM
Abnormal T-wave morphology
Prolonged QTc
Evidence of atrial dilatation
Abnormal QRS axis
Presence of abnormal Q-waves
Evidence of left ventricular hypertrophy*
Evidence of bundle branch block
Repolarisation abnormalities (including ST-segment elevation/depression, abnormal T-wave inversion, abnormal T-wave morphology, prolonged QTc†)
  • *Defined as Sokolow-Lyon Score >35 mm, on the 12-lead ECG only.

  • †A prolonged QTc was defined as >450 ms in males and >460 ms in females.25

  • HCM, hypertrophic cardiomyopathy; LQTS, long QT syndrome; QTc, corrected QT interval.