A shunt (see patent foramen ovale and atrial septal defect) between the two systems will ensue if possible to reestablish the equilibrium.
[5] Men, on average, have higher stroke volumes than women due to the larger size of their hearts.
Corresponding to the oxygen uptake, women's need for blood flow does not decrease and a higher cardiac frequency makes up for their smaller stroke volume.
[7] Prolonged aerobic exercise training may also increase stroke volume, which frequently results in a lower (resting) heart rate.
Reduced heart rate prolongs ventricular diastole (filling), increasing end-diastolic volume, and ultimately allowing more blood to be ejected.
[8] Stroke volume is intrinsically controlled by preload (the degree to which the ventricles are stretched prior to contracting).