Do people in a medical induced coma have to be on a machine to circulate their blood?

Circulatory pump: Mechanical circulatory devices are used for temporary support of certain patients w/ severe heart problems; some machines which pump and oxygenate the blood may be used for treating severe lung diseases as well. Patients whose hearts and lungs are ok but who are deeply sedated may be supported with a mechanical ventilator to move air in & out of the lungs but would not generally need a heart pump.