Final answer:
Cocaine prevents nerve cells from taking up dopamine, leading to vasoconstriction, increased blood pressure, and the risk of heart problems.
Step-by-step explanation:
The reason why cocaine has such extreme effects on the heart is due to its ability to prevent nerve cells from taking up dopamine from the synapse. By preventing the reuptake of dopamine, cocaine increases the levels of this neurotransmitter in the brain, which stimulates the pleasure centers and creates a euphoric effect. However, this excessive dopamine action can lead to vasoconstriction, which narrows the blood vessels and reduces blood flow to the heart.
This vasoconstriction can increase the workload on the heart and cause an increase in blood pressure. Additionally, cocaine use can also lead to arrhythmias and increase the risk of stroke, heart attack, and sudden cardiac death.