The Frank-Starling law of the heart is a physiological concept that states that the force of contraction of the cardiac muscle is proportionate to its starting length. The Frank-Starling law is also known as the Frank-Starling mechanism. It is the basic principle of cardiac performance.
The Frank-Starling law of the heart was named after Otto Frank and Ernest Starling. They were the first physiologists that described the concept. They proposed that the longer the cardiac muscle is stretched, the greater the muscle contraction. This means that the heart's diastolic expansion is directly proportional to the strength of the heart's systolic contraction. When there is an increase in the diastolic expansion, the systolic contraction will also increase.