Which statement is true regarding negative inotropes?

Negative inotropes are agents that decrease the force of myocardial contractions. Therefore, the statement that they decrease the heart's workload is accurate. By reducing the strength of each heartbeat, negative inotropes effectively lower the overall myocardial oxygen demand and energy expenditure. This can be particularly beneficial in conditions where the heart is under stress or in cases of heart failure, where excessive workload can exacerbate the patient's condition.

In contrast, stating that negative inotropes increase the heart's contraction force, are used to treat cardiogenic shock, or enhance calcium influx into heart muscle cells misrepresents their pharmacological effects. Negative inotropes typically work by reducing intracellular calcium levels or blocking calcium entry, thereby diminishing the contractility. This makes them useful in specific clinical contexts but not for increasing cardiac output or treating conditions like cardiogenic shock, where improved contractility is often necessary.