TY - JOUR

T1 - Left ventricular mechanics in humans with high aerobic fitness

T2 - adaptation independent of structural remodelling, arterial haemodynamics and heart rate

AU - Stöhr, Eric J.

AU - McDonnell, Barry

AU - Thompson, Jane

AU - Stone, Keeron

AU - Bull, Tom

AU - Houston, Rory

AU - Cockcroft, John

AU - Shave, Rob

PY - 2012/5

Y1 - 2012/5

N2 - Individuals with high aerobic fitness have lower systolic left ventricular strain, rotation and twist ('left ventricular (LV) mechanics') at rest, suggesting a beneficial reduction in LV myofibre stress and more efficient systolic function. However, the mechanisms responsible for this functional adaptation are not known and the influence of aerobic fitness on LV mechanics during dynamic exercise has never been studied. We assessed LV mechanics, LV wall thickness and dimensions, central augmentation index (AIx), aortic pulse wave velocity (aPWV), blood pressure and heart rate in 28 males (age: 21 ± 2 years SD) with a consistent physical activity level (no change >6 months). Individuals were examined at rest and during exercise (40% peak exercise capacity) and separated post hoc into a moderate and high aerobic fitness group (: 49 ± 5 and 63 ± 7 ml kg -1 min -1, respectively, P < 0.0001). At rest and during exercise, there were no significant differences in gross LV structure, AIx, blood pressure or heart rate (P > 0.05). However, for the same AIx, the high group had significantly lower LV apical rotation (P= 0.002) and LV twist (P= 0.003) while basal rotation and strain indices did not differ between groups (P > 0.05). We conclude that young males with high aerobic fitness have lower LV apical rotation at rest and during submaximal exercise that can occur without changes in gross LV structure, arterial haemodynamics or heart rate. The findings suggest a previously unknown type of physiological adaptation of the left ventricle that may have important implications for exercise training in older individuals and patient populations in which exercise training has previously failed to show clear benefits for LV function.

AB - Individuals with high aerobic fitness have lower systolic left ventricular strain, rotation and twist ('left ventricular (LV) mechanics') at rest, suggesting a beneficial reduction in LV myofibre stress and more efficient systolic function. However, the mechanisms responsible for this functional adaptation are not known and the influence of aerobic fitness on LV mechanics during dynamic exercise has never been studied. We assessed LV mechanics, LV wall thickness and dimensions, central augmentation index (AIx), aortic pulse wave velocity (aPWV), blood pressure and heart rate in 28 males (age: 21 ± 2 years SD) with a consistent physical activity level (no change >6 months). Individuals were examined at rest and during exercise (40% peak exercise capacity) and separated post hoc into a moderate and high aerobic fitness group (: 49 ± 5 and 63 ± 7 ml kg -1 min -1, respectively, P < 0.0001). At rest and during exercise, there were no significant differences in gross LV structure, AIx, blood pressure or heart rate (P > 0.05). However, for the same AIx, the high group had significantly lower LV apical rotation (P= 0.002) and LV twist (P= 0.003) while basal rotation and strain indices did not differ between groups (P > 0.05). We conclude that young males with high aerobic fitness have lower LV apical rotation at rest and during submaximal exercise that can occur without changes in gross LV structure, arterial haemodynamics or heart rate. The findings suggest a previously unknown type of physiological adaptation of the left ventricle that may have important implications for exercise training in older individuals and patient populations in which exercise training has previously failed to show clear benefits for LV function.

UR - http://www.scopus.com/inward/record.url?scp=84860350183&partnerID=8YFLogxK

U2 - 10.1113/jphysiol.2012.227850

DO - 10.1113/jphysiol.2012.227850

M3 - Article

C2 - 22431336

AN - SCOPUS:84860350183

VL - 590

SP - 2107

EP - 2119

JO - Journal of Physiology

JF - Journal of Physiology

SN - 0022-3751

IS - 9

ER -