a) High blood pressure
- High blood pressure damages the arteries, causing it to become less elastic. In return, blood and oxygen flow to the heart is decreased, increasing heart workload.
b) Massive bleeding
- Excessive bleeding causes a decrease in blood volume, therefore reducing cardiac output.
c) the drug dopamine
- The myocardium responds favorably to dopamine's chronotropic and inotropic effects, increasing cardiac contractility and heart rate.
d. Running a sprint
- Engaging in high-intensity workouts, such as running a sprint, heart rate and stroke volume increases as the body requires more oxygen, which also increases cardiac output.
e. Hyperthryoidism with increased secretion of thyroid hormones
- Hyperthryoidism causes serious complications, such as an increased heart rate (tachycardia), causing increased cardiac output. Excessive thyroxine produced can also alters the heart's hemodynamics increasing preload and contractility.
f. Massive myocardial infarction (cardiac tissue death)
- A heart attack, or massive myocardial infarction occurs when blood muscles do not receive oxygenated blood caused by factors such as blockages in the arteries. This results in decreased cardiac output because of decreased blood flow.
g. Hypothermia
- Prolonged exposure to freezing temperatures can cause hypothermia, reducing core temperature. This leads to a decreasing heart rate, and a decreased cardiac output.
h. Emotional distress
- Emotional distress prompts the release of hormones such as cortisol and adrenaline, causing an increase in heart rate and cardiac output.