Within a normal physiologic range, an increase in left ventricular end-diastolic volume leads to:
A) an increased force of contraction.
B) a decrease in cardiac output.
C) an increase in heart rate.
D) heart failure.

Question

Quizplus · Accepted Answer

An increase in left ventricular end-diastolic volume (preload) stretches the myocardial fibers leading to an increase in the force of contraction (Frank-Starling mechanism), thus increasing the stroke volume and cardiac output. A decrease in preload can decrease the force of contraction leading to a decrease in cardiac output. An increase in heart rate can also increase cardiac output but is not solely dependent on preload. Heart failure is a pathological condition that occurs when the heart is unable to meet the body's demands for oxygen and nutrients.

Within a Normal Physiologic Range, an Increase in Left Ventricular