Final answer:
The purpose of the beta blocker for heart failure is to prevent stimulation of the heart by catecholamines.
Step-by-step explanation:
The purpose of the beta blocker for a patient with heart failure is to prevent stimulation of the heart by catecholamines. Beta blockers work by blocking beta receptors in the heart, which reduces the heart's response to catecholamines such as norepinephrine and epinephrine. This helps to decrease the workload on the heart and improve its function.