Abstract:
Cardiac output is amount of blood pumped out of the heart each minute.
Cardiac output = Stroke volume x heart rate.
Because there is a correlation between resting cardiac output (COP) and surface area of the body, it is important to find some mean by which COP of different sized people can be compared with one another. The COP is frequently stated in term of the cardiac index (CI), which is the cardiac output /minute / m² of body surface. The normal average of cardiac index for adult is about 3.2 L.
COP depends on two major factors:
1-Heart rat.
2- Stroke volume.
Effect of volume and pressure over load:
Prolonged volume over load lead to eccentric hypertrophy. Left ventricle undergoes hypertrophy, entire chamber enlarges with a large increase in left ventricle volume, little increase in wall thickness with chronic ventricular dilatation, and stroke volume is triple.
Prolonged pressure over load will cause hypertrophy of ventricular wall (concentric hypertrophy). In concentric hypertrophy, there is an increase in thickness of ventricular wall, but ventricular end-diastolic volume remains unchanged.