Normal rotational, torsion and untwisting data in children, adolescents and young adults.

Background: Left ventricular (LV) torsion and untwisting are important components of LV performance, but there is little information on the effect of age, particularly in younger populations.

Methods: LV rotation and LV rotation rate, torsion, recoiling, and untwisting were measured in normal subjects (n=111) aged 3 to 40 years (mean age, 19.3 years) using speckle-tracking imaging.

Results: LV torsion increased with age because of the augmentation of apical LV rotation, but this disappeared when normalized by LV length. Although peak LV torsion and apical LV rotation increased with age, the normalized peak torsion rate decreased. As well, the peak untwisting rate decreased with age and was enhanced when normalized by LV length. Younger hearts demonstrated greater untwisting and recoiling of the apex during isovolumic relaxation and early diastole. The time difference between apical and basal events decreased with advancing age.

Conclusion: The heart maintains a constant LV torsion and LV rotation profile when normalized by length and cardiac cycle. Younger hearts tend to twist, untwist, and deform faster.