CLINICAL MEDICINE

Detailed explanation-1: -There are three variables affecting stroke volume, which include contractility, preload, and afterload.

Detailed explanation-2: -The Frank–Starling law of the heart dictates that cardiac output is related to end-diastolic volume, a component of cardiac preload; for this reason adequate venous return is vital to ensuring appropriate perfusion.

Detailed explanation-3: -SV is the difference between end diastolic volume (EDV) and end systolic volume (ESV). Multiple factors can affect SV, eg. factors that change either EDV or ESV will change SV. The three primary factors that regulate SV are preload, afterload and contractility. Heart rate (HR) also affects SV.

Detailed explanation-4: -According to Starling’s law of the heart, a change in preload, approximated by the end diastolic volume and determined by the venous return of blood to the heart, directly results in a change in stroke volume, defining myocardial function.