Final answer:
During pregnancy, anticipated changes in heart function include increased heart rate, stroke volume, cardiac output, and blood volume to support the growing fetus. Cardiac output is determined by the heart rate and the stroke volume, which can be influenced by various factors including preload and contractility.
Step-by-step explanation:
The anticipated change in heart function during pregnancy is an increase in several key areas: heart rate, stroke volume, cardiac output (CO), and blood volume. Blood volume increases substantially, by approximately 30 percent or 1-2 liters, to meet the demands of fetal nourishment and waste removal. This expansion in blood volume can lead to a moderate rise in both pulse and blood pressure during pregnancy.
Cardiac output is the volume of blood the heart pumps in one minute and is a product of heart rate multiplied by stroke volume. Factors that affect stroke volume include preload, contractility, and the difference between end-diastolic volume (EDV) and end-systolic volume (ESV). Positive factors that affect heart contractility and thereby increase CO include increased sympathetic stimulation, while negative factors include hypoxia and acidosis.
During pregnancy, the cardiac response to changes in blood flow and pressure includes an increase in heart rate and stroke volume to accommodate the greater circulatory demands. The heart adapts to ensure that the growing fetus receives sufficient oxygen and nutrients while also managing the increased total blood volume.