Age, Gender and Hypertension-Related Remodeling Influences Left Ventricular Torsion Assessed by Tagged Cardiac Magnetic Resonance in Asymptomatic Individuals: The Multi-Ethnic Study of Atherosclerosis
Background—The aim of the present study was to evaluate how torsion is influenced by left ventricular (LV) remodeling associated with age, gender and hypertension in a large community-based population.
Methods and Results—Myocardial shortening and torsion were assessed by tagged cardiac magnetic resonance (CMR) in 1478 participants without clinically apparent cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis (MESA). Torsion was defined as the difference between apical and basal rotation, divided by slice distance. In multivariable linear regression models, older age was associated with lower stroke volume (-3.6 ml/decade, p<0.001) and higher LV mass-to-volume ratio (0.03 g/ml/decade, p<0.001) along with lower circumferential shortening (-0.17%/decade, p<0.05). Torsion, however, was greater at older ages (0.14 °/decade, p<0.001) and in women (0.37°/cm vs. men, p<0.001). Hypertensive participants had higher LV mass and LV mass-to-volume ratio (15.5g and 0.07 g/ml, respectively, p<0.001 for both). Circumferential shortening was lower in hypertensive (-0.42%, p<0.01), whereas torsion was higher after adjustment for age and gender (0.17°/cm, p<0.05).
Conclusions—Older age is associated with lower LV volumes and greater relative wall thickness, and accompanied by lower circumferential myocardial shortening, whereas torsion is greater with older age. Hypertensive individuals have greater LV volumes and relative wall thickness and lower circumferential shortening. Torsion, however, is greater in hypertension independent of age and gender. Torsion may therefore represent a compensatory mechanism to maintain an adequate stroke volume and cardiac output in the face of progressively reduced LV volumes and myocardial shortening associated with hypertension and aging.
- Received January 16, 2012.
- Accepted September 17, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited