What does a negative ionotropic agent do to the heart?

A negative inotropic agent is a substance that decreases the force and strength of heart muscle contractions. This means that when such an agent is present, the heart’s ability to contract with strong force is reduced, leading to fewer effective contractions with every heartbeat. As a result, the heart does not pump blood as efficiently, which can affect overall cardiac output and might lead to various physiological changes in the body.

The other choices do not align with the effects of negative inotropic agents. For instance, a negative inotropic agent would not increase heart rate or stroke volume, as its primary function is to weaken the contractility of the heart muscle. An increase in blood pressure typically arises from enhanced cardiac output or resistance, factors not associated with a decrease in contraction strength. Thus, understanding the role of negative inotropic agents is essential for comprehending how different substances can influence heart function and overall cardiovascular health.