a. High blood pressure - During high blood pressure, more pressure is exerted in the artery walls which may cause the heart rate to increase, that decreases preload decreasing contraction and increasing afterload.
b. Massive bleeding - In massive bleeding, the body loses blood increasing heart rate thus decreases preload which decreases contraction and increases afterload.
c. the drug dopamine - The drug dopamine improves the heart's pumping strength which causes the heart rate to increase causing preload to decrease which decreases contraction and increases afterload.
d. Running a sprint - When running a sprint, the body from rest needs more oxygen than usual. This causes the heart rate to increase to accommodate for the oxygen needed by the body, and the muscles increase the stroke volume to send higher amounts of blood volume back to the lungs for oxygen.
e. Hyperthryoidism with increased secretion of thyroid hormones - Hyperthyroidism is the overactivity of the thyroid gland which increases heart rate that may decrease preload, decrease contraction and increase afterload which may result to heart failure.
f. Massive myocardial infarction (cardiac tissue death) - The cardiac tissue is important as it is found in the heart and this tissue could die due to a blockage in blood supply, when this occurs a heart attack may happen that causes heart rate to vary (too slow or fast) depending on the person. This causes lack of blood supply in the heart which makes it unable to pump thus lowering cardiac output.
g. Hypothermia - When one is experiencing hypothermia, the body temperature is lower than usual in which the heart rate slows causing an increase in the preload, increase in contraction, and decrease in afterload.
h. Emotional distress - Emotional distress decreases cardiac output which means the preload is decreased, the contraction is decreased, and the afterload is increased.