Normal Rotational, Torsion and Untwisting Data in Children, Adolescents and Young Adults
published online 25 January 2010.
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.
aDepartment of Pediatrics, Division of Pediatric Cardiology, University of Alberta and Stollery Children's Hospital, Edmonton, Alberta, Canada
bDepartment of Biomedical Engineering, University of Alberta and Stollery Children's Hospital, Edmonton, AB, Canada
Reprint requests: Jeffrey F. Smallhorn, MBBS, University of Alberta Hospital, Room 4C2, Walter C. Mackenzie Health Sciences Centre, Edmonton, Alberta T6G 2B7, Canada.
ABSTRACT