Written by the Fiveable Content Team • Last updated August 2025
Written by the Fiveable Content Team • Last updated August 2025
Definition
Preload is the degree of stretch of the cardiac muscle fibers at the end of diastole, just before contraction. It directly influences the force of myocardial contraction according to Frank-Starling law.
The sequence of mechanical and electrical events that repeat with every heartbeat, including diastole and systole phases.
Frank: Starling Law - A principle stating that the stroke volume of the heart increases in response to an increase in volume of blood filling the heart (the end diastolic volume), when all other factors remain constant.