<prompt> Which of the following is most cardio depressantHalothaneIsofluraneSevofluraneDesflurane  <response>: Halothane is direct myocardial depressant, decreases SA node activity and decreases hea rate. Also sensitizes the hea to the arrhythmogenic effectsof epinephrine and hence is contraindicated in pheochromocytoma. Isoflurane , sevoflurane and desflurane at required MAC does not cause much cardiac depression. They dilate the blood vessels and decreases the mean aerial pressure . 