Final answer:
Halothane is a negative inotropic agent that reduces cardiac contractility and subsequently decreases the stroke volume of the heart.
Step-by-step explanation:
Halothane is an inhalational anesthetic known to have effects on the heart's contractility. Specifically, halothane acts as a negative inotropic agent, which means it reduces the force of the heart's contractions. This is in contrast to substances like epinephrine and NE (norepinephrine), which act as positive inotropic agents increasing the strength of heart contractions by stimulating the influx of calcium ions.
Similarly, drugs such as digitalis can increase the contractility by leading to higher intracellular calcium levels. However, in the case of halothane, the reduction in myocardial contractility can lead to a decrease in stroke volume, which is the amount of blood ejected by the heart in each beat.