Cardiac Output Flashcards
What is cardiac output (CO)?
The volume of blood pumped by the heart per minute.
What is the formula for CO?
CO = Stroke Volume (SV) × Heart Rate (HR).
What are the normal values of CO?
~5 L/min at rest, increases with exercise.
What are the primary factors affecting CO?
End-Diastolic Volume (EDV), Peripheral Resistance, and Myocardial Contractility.
What is End-Diastolic Volume (EDV)?
The volume of blood in the ventricles at the end of diastole (filling phase).
How does EDV affect CO?
Higher EDV increases stroke volume (SV) via the Frank-Starling mechanism.
What are the factors affecting EDV?
Venous return, filling time (HR), atrial contraction, and ventricular compliance.
How does venous return affect EDV?
More venous return → higher EDV → increased CO.
How does heart rate affect EDV?
Very high HR reduces filling time → lowers EDV → decreases CO.
What is peripheral resistance?
The resistance blood faces as it flows through vessels.
How does peripheral resistance affect CO?
Higher resistance increases afterload → reduces CO.
What factors increase peripheral resistance?
Vasoconstriction, increased blood viscosity, and plaque formation.
What factors decrease peripheral resistance?
Vasodilation and lower blood viscosity.
