<prompt> Which of the following would cause a decrease in stroke volume, when compared with the normal resting value?Reduction in afterloadAn increase in end-diastolic pressureStimulation of the vagus nervesElectrical pacing to a hea rateof 200 beatsmin  <response>: Electrical pacing to a hea rate of 200 beatsmin would decrease the time for filling and reduce end-diastolic volume.A reduction in afterload would make it easier for the ventricle to eject blood and would raise stroke volume.An increase in end-diastolic pressure will increase end-diastolic fiber length and increase the force of contraction and stroke volume.Stimulation of the vagus nerves slows the hea, increases the time for ventricular filling, and increases stroke volume.Stimulation of sympathetic nerves to the hea increases hea rate and contractility.Despite the decreased filling accompanying an increase in hea rate, stroke volume will stay the same or increase because of the increased contractility 