Within normal limits, an increase in preload leads to
A) an increase in cardiac output and force of left ventricular contraction.
B) a decrease in cardiac output and force of left ventricular contraction.
C) an increase in cardiac output and a decrease in the force of left ventricular contraction.
D) a decrease in cardiac output and an increase in the force of left ventricular contraction.
E) a decrease in stroke volume and heart rate.

Question

Quizplus · Accepted Answer

According to the Frank-Starling law of the heart, within physiological limits, an increase in preload (the end-diastolic volume or pressure that stretches the ventricles of the heart) leads to an increase in cardiac output and force of left ventricular contraction. This is because the myocardial fibers are stretched to a more optimal length for force generation.

Within Normal Limits, an Increase in Preload Leads to