Which anaesthetics are noted to cause myocardial depression?

Myocardial depression refers to the reduction in the heart's ability to contract effectively, which can lead to decreased cardiac output and potential hemodynamic instability. Among the anesthetics listed, propofol and sodium thiopentone are particularly noted for their myocardial depressant effects.

Propofol is known for inducing sedation and is commonly used for induction and maintenance of anesthesia. It causes vasodilation, leading to a decrease in systemic vascular resistance, which can subsequently lower blood pressure and result in myocardial depression. Sodium thiopentone, a barbiturate, also has a similar profile; it can cause cardiovascular depression by decreasing myocardial contractility and causing vasodilation.

While etomidate has minimal cardiovascular effects, making it less likely to cause myocardial depression, and ketamine is generally considered to have a more stimulating effect on the cardiovascular system (often increasing heart rate and blood pressure), they do not play a significant role in myocardial depression compared to the aforementioned agents. Therefore, the focus on the myocardial depressant properties of propofol and sodium thiopentone justifies the selection of this option.