All of the following cause myocardial depression except:

B i.e. Etomidate - Etomidate causes adreno - coical suppressionQ by inhibiting enzymes 11/3 hydroxylase (mainly) & 17 a hydroxylase involved in coisol and aldosterone (mineralocoicoid) productionQ. Vit C supplimentation restores coisol level. - Etomidate and midazolam provide cardiovascular stabilityQ. But etomidate is most cardiostable agentQ that causes the least hemodynamic disturbance of any of the intravenous anesthetic agents. So it is intravenous anesthetic agent of choice for patients with cardiac disease and aneurysm surgeryQ. - Direct myocardial depression is caused by halothane (severe), nitrous oxide (moderate), iso/sevo/des-flurane (mild), thiopental (marked), propofol (dose dependent) and ketamineQ (but this is masked by cardiotonic sympathetic stimulatory action). Etomidate > midazolem are most cardiostable agentsQ.