title: 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.
authors.affiliation: Department of Anatomy with Radiology, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors.forename: Carissa G
authors.initials: CG
authors.lastname: Fonseca
authors.forename: Helen C
authors.initials: HC
authors.lastname: Oxenham
authors.forename: Brett R
authors.initials: BR
authors.lastname: Cowan
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Occleshaw
authors.forename: Alistair A
authors.initials: AA
authors.lastname: Young
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D003971:Diastole / Q000502:physiology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D013599:Systole / Q000502:physiology; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology