Cardiac Output and Venous Return Quiz

Cardiac Output

• Factors that can affect cardiac output include various physiological and pathological conditions.
• The equation for cardiac index is: Cardiac Index (CI) = Cardiac Output (CO) / Body Surface Area (BSA)

Determinants of Cardiac Output

• Under normal conditions, heart rate is the most important determinant of cardiac output.
• The equation for cardiac output is: Cardiac Output (CO) = Heart Rate (HR) x Stroke Volume (SV)
• Heart rate is primarily controlled by the autonomic nervous system, particularly the sympathetic nervous system.

Effects of Total Peripheral Resistance on Cardiac Output

• A decrease in total peripheral resistance (TPR) leads to an increase in cardiac output.

Effects of Sympathetic Activation and Cardiac Hypertrophy

• Sympathetic activation and cardiac hypertrophy increase cardiac output.

Regulation of Coronary Blood Flow

• Myocardial oxygen demand is the major regulator of coronary blood flow.

Indicator Dilution Method

• The equation to calculate cardiac output using the indicator dilution method is: Cardiac Output (CO) = Quantity of Indicator / (A - V) x (t2 - t1)

Venous Return

• The principal factors that affect venous return are: venous tone, blood volume, and pumping action of the skeletal muscles.
• The equation to calculate venous return is: Venous Return (VR) = (Right Atrial Pressure - Mean Circulatory Pressure) / Resistance to Venous Return