Final answer:
Hypocalcemia is a negative inotropic agent that lowers the strength of heart muscle contractions, which is the opposite effect of hypercalcemia, a positive inotropic agent.
Step-by-step explanation:
Hypocalcemia is a condition characterized by abnormally low levels of calcium in the blood. Having low calcium levels can have various negative effects on the body, including its impact on the heart's contractility. In terms of cardiac function, hypocalcemia would be considered a negative inotropic agent because it can decrease the strength of heart muscle contraction. This is in contrast to high calcium levels, or hypercalcemia, which acts as a positive inotropic agent by increasing heart contractility. Negative inotropic factors diminish the force of contraction, and besides hypocalcemia, they include other conditions such as hypoxia, hyperkalemia, and the use of certain drugs like beta blockers and calcium channel blockers.