Which of the following factor is determined by preload?
End systolic volume
End diastolic volume
Peripheral resistance
Stroke volume
Preload is the initial stretching of the cardiac myocytes prior to contraction; therefore, it is related to the sarcomere length at the end of diastole. Sarcomere length cannot be determined in the intact hea so indirect indices of preload, such as ventricular end-diastolic volume or pressure, must be used. Ref: Cardiovascular Physiology Concepts By Richard E. Klabunde, 2005, Page 69; Guyton's physiology 22nd edition, Page 111.