The nurse is assessing a patient who is receiving metoprolol 2 days after an acute coronary syndrome (ACS), Which physiological action of metoprolol supports the desired or therapeutic response?

A) Increases contractility: Metoprolol, a beta-blocker, actually decreases contractility. It reduces the force of contraction of the heart muscle, which can help reduce myocardial oxygen demand and improve outcomes after ACS. Increasing contractility would counteract the therapeutic goals of metoprolol in managing ACS. B) Increases preload: Preload refers to the volume of blood in the ventricles at the end of diastole. Metoprolol does not increase preload; rather, it reduces myocardial workload and oxygen demand, which does not directly affect preload but rather the heart's performance overall. C) Decreases afterload: Metoprolol reduces afterload indirectly by lowering blood pressure and decreasing heart rate, which helps reduce the workload on the heart. This reduction in afterload supports the therapeutic goals of metoprolol in managing ACS by decreasing the heart's work and improving cardiac efficiency. D) Decreases diastolic filling time: Metoprolol slows the heart rate, which can lead to increased diastolic filling time, not a decrease. Increased filling time can be beneficial as it allows the heart more time to fill with blood between beats, thereby improving cardiac output.