Final answer:
Carvedilol is a beta-blocker that decreases the heart rate and the strength of heart's contractions, reducing the heart's workload after an acute myocardial infarction, thus helping in the heart's recovery.
Step-by-step explanation:
The nurse should explain that carvedilol is a type of medication known as a beta-blocker, which serves the purpose of reducing the workload on the heart after an acute myocardial infarction. Beta-blockers function by blocking the beta-1 receptors in the heart muscle, which are binding sites for neurotransmitters like norepinephrine (NE) that would typically increase the heart rate and force of contraction. By blocking these receptors, beta-blockers decrease the heart rate and the strength of the heart's contractions, leading to a reduction in the heart's oxygen demand and an overall decrease in the workload on the heart. This helps the heart to work more efficiently and can aid in preventing further heart damage. Therefore, the correct response to the client's question is option D: 'This drug will decrease the workload on your heart'.