Cardiac Output
Posted: Sunday, June 21st, 2020 | Updated: Monday, February 7th, 2022
Posted: Sunday, June 21st, 2020 | Updated: Monday, February 7th, 2022
The Definition of Cardiac Output
The amount of blood leaving the heart
Cardiac Output is Determined By
Stroke Volume:
The amount of blood ejected with each contraction of the heart
Heart Rate:
Rate of cardiac contractions
Equation for Determining Cardiac Output
Cardiac Output = Stroke Volume x Heart Rate
Scenarios
If your patient has a low blood pressure, the stroke volume is reduced. The heart rate must increase so the cardiac output is maintained. If your patient has a high blood pressure, the stoke volume is increased. The heart rate must then decrease to maintain the appropriate cardiac output. During the fight or flight response, the sympathetic nervous system releases epinephrine which increases the heart rate and stroke volume to prepare for the suspected cardiac output demand. General anesthesia often stimulates the parasympathetic nervous system releasing acetylcholine which decreases the heart rate and the stroke volume resulting in a lowered cardiac output
The amount of blood leaving the heart
Cardiac Output is Determined By
Stroke Volume:
The amount of blood ejected with each contraction of the heart
Heart Rate:
Rate of cardiac contractions
Equation for Determining Cardiac Output
Cardiac Output = Stroke Volume x Heart Rate
Scenarios
If your patient has a low blood pressure, the stroke volume is reduced. The heart rate must increase so the cardiac output is maintained. If your patient has a high blood pressure, the stoke volume is increased. The heart rate must then decrease to maintain the appropriate cardiac output. During the fight or flight response, the sympathetic nervous system releases epinephrine which increases the heart rate and stroke volume to prepare for the suspected cardiac output demand. General anesthesia often stimulates the parasympathetic nervous system releasing acetylcholine which decreases the heart rate and the stroke volume resulting in a lowered cardiac output
Sources:
Colville, Thomas, and Joanna M. Bassert. Clinical Anatomy and Physiology for Veterinary Technicians. 2nd ed. Mosby Elsevier, 2008.
Colville, Thomas, and Joanna M. Bassert. Clinical Anatomy and Physiology for Veterinary Technicians. 2nd ed. Mosby Elsevier, 2008.