Left ventricular mechanical limitations to stroke volume in healthy humans during incremental exercise.

@article{Sthr2011LeftVM,
  title={Left ventricular mechanical limitations to stroke volume in healthy humans during incremental exercise.},
  author={Eric J St{\"o}hr and Jos{\'e} Gonz{\'a}lez-Alonso and Rob E. Shave},
  journal={American journal of physiology. Heart and circulatory physiology},
  year={2011},
  volume={301 2},
  pages={
          H478-87
        }
}
During incremental exercise, stroke volume (SV) plateaus at 40-50% of maximal exercise capacity. In healthy individuals, left ventricular (LV) twist and untwisting ("LV twist mechanics") contribute to the generation of SV at rest, but whether the plateau in SV during incremental exercise is related to a blunting in LV twist mechanics remains unknown. To test this hypothesis, nine healthy young males performed continuous and discontinuous incremental supine cycling exercise up to 90% peak power… 
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It is demonstrated that EDV does not increase upon exercise at high altitude despite enhanced in vivo diastolic relaxation, and the increase in LV mechanics at rest may represent a mechanism by which SV is defended in the presence of a reduced EDV.
The Effects of Exercise Intensity vs. Metabolic State on the Variability and Magnitude of Left Ventricular Twist Mechanics during Exercise
TLDR
During exercise, the intra-individual variability of LV twist mechanics is smaller at the same relative exercise intensity compared with IAT, but the absolute magnitude (degrees) ofLV twist mechanics appears to be associated with the prevailing rate pressure product.
Maximal heart rate does not limit cardiovascular capacity in healthy humans: insight from right atrial pacing during maximal exercise
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Dehydration reduces stroke volume and cardiac output during exercise because of impaired cardiac filling and venous return, not left ventricular function
TLDR
The findings suggest that the decline in SV underpinning the blunted Q˙ with exercise‐induced dehydration is caused by compromised LV filling and venous return, but not intrinsic systolic or diastolic LV function.
Synergy in the heart: RV systolic function plays a key role in optimizing LV performance during exercise.
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This work provides mechanistic understanding of the pivotal role of the RV in optimizing LV SV during exercise and demonstrates why optimizing RV function needs to become a key part of therapeutic strategies in patients and training for athletes.
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