Cardiac Output Flashcards
What is cardiac output?
: Cardiac output is the amount of blood the heart pumps per minute.
What two factors determine cardiac output?
Stroke volume and heart rate
What is stroke volume (SV)?
Stroke volume is the amount of blood ejected from the ventricles with each contraction.
What are the three main factors that affect stroke volume?
Preload, contractility, and afterload.
What is preload?
Preload is the volume of blood in the ventricles at the end of diastole (before contraction), affecting the force of the next contraction.
What is contractility
Contractility is the strength of the heart’s contraction. Higher contractility increases stroke volume.
What is afterload?
Afterload is the resistance the ventricles must overcome to eject blood into the arteries. High afterload can reduce stroke volume.
What is heart rate (HR)
Heart rate is the number of times the heart beats per minute.
How is cardiac output calculated?
Cardiac output (CO) = Stroke volume (SV) × Heart rate (HR).
What factors can affect cardiac output?
A: Autonomic nervous system, blood volume, physical activity, and health conditions like heart failure or hypertension
