A Change in Preload Causes a Change in Myocardial Contractile

Question

A change in preload causes a change in myocardial contractile force.This response is known as (a)
A) (+) inotropic effect.
B) (+) dromotropic effect.
C) Starling's law of the heart.
D) (-) chronotropic effect.

Accepted Answer

Starling's law of the heart states that the greater the stretch of the cardiac muscle (due to an increase in preload), the greater the force of contraction. This is a fundamental concept behind the regulation of cardiac output and a key factor in the Frank-Starling mechanism. Choices A, B, and D refer to other aspects of cardiac physiology, but are not directly related to changes in preload.