A 56 year male with history of myocardial ischemia is posted for cholecystectomy. The most preferred opioid would be:
a. Morphine shifts blood from pulmonary to systemic circulation therapy decreasing the chances of left ventricular failure.
b. Rest of other agents like pethidine, pentazocine and butorphanol causes tachycardia so should not be used in patients of myocardial ischemia.