Tthe force of contraction depends on the length of muscle fibers of the heart wall.
The greater the stretch of cardiac muscle, the greater the force of contraction. This means that when there is an unusual increase in volume of blood entering the heart, the ventricular wall stretches causing the cardiac muscle to contract more forcefully. Since there is an increase of the load experienced by each muscle fiber the result is greater heart contraction and beat.
Word origin: named after the two physiologists, Otto Frank and Ernest Starling who first described it.
Also called: law of the heart, Starling’s law, Frank-Starling mechanism.