Aging alters patterns of regional nonuniformity in LV strain relaxation: a 3-D MR tissue tagging study

Abstract

Although age-related impairment of diastolic function is well documented, patterns of regional tissue relaxation impairment with age have not been characterized. MRI tissue tagging with a regional three-dimensional (3-D) analysis was performed in 15 younger (age 19–26 yr) and 16 older (age 60–74 yr) normal, healthy volunteers. The peak rate of relaxation of circumferential strain (RC) was decreased in the older group (on average, 105 ± 28 vs. 163 ± 18 %/s for older vs. younger, mean ± SD, P < 0.001) to a greater extent in the lateral wall than in the septum ( P = 0.016) and to a greater extent in the apex than in the base ( P < 0.001). Peak rate of relaxation of longitudinal strain (RL) was also reduced with age (94 ± 27 vs. 155 ± 18 %/s, P < 0.001) to a greater extent in the apex than in the base ( P < 0.001). Both RC and RL were greater in the apex than in the base only in the younger subjects ( P < 0.001 for each). Peak rate of torsion reversal (RT) was reduced with age (74 ± 16 vs. 91 ± 15 degrees/s, P = 0.006) to a greater extent in the base than in the apex ( P = 0.035). An increase in regional asynchrony in time to RC and time to RL ( P < 0.001 for each), but not time to RT, occurred with age. Thus patterns of regional nonuniformity of myocardial relaxation are altered in a consistent fashion with aging.