a. High blood pressure
Increased blood pressure means increased heart rate. There is also an increase in contractile responses and preload as well as an increase in the afterload in the left ventricle of the heart, increasing cardiac output.
b. Massive bleeding
Loss of blood results in a lesser amount of ventricular filling, reducing the preload. However, this would urge the heart to compensate for the blood loss through increasing heart rate and contractility.
c. The drug dopamine
There is an increase in the cardiac output as dopamine results in an increase in heart rate and contractility. Additionally, more doses of the said drug can increase afterload.
d. Running a sprint
When running, the heart rate increases along with the contractility that will result in an increased cardiac output.
e. Hyperthryoidism with increased secretion of thyroid hormones
Hyperthyroidism can result in an increase in cardiac output. The increased secretion of thyroid hormones can increase heart rate and contractility.
f. Massive myocardial infarction (cardiac tissue death)
Myocardial infarction reduces cardiac output. There is a decrease in the preload and afterload.
g. Hypothermia
During low temperatures, heart rate will increase and contractility therefore increases cardiac output to fight off the decrease in temperature.
h. Emotional distress
Stress increases the body’s demand for oxygen. This leads to an increase in heart rate and contractility, elevating cardiac output.
References
Tortora, G. J., & Derrickson, B. (2017). Principles of anatomy and physiology (14th ed.). Wiley Custom Learning Solutions
Vincent, J.-L. (2008). Understanding cardiac output. Critical care. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2575587/