Abstract: An apparatus and system for administering cardioplegic solution to a heart during open heart surgery. A source of solution is delivered to a control switch from a single tube source and the tube is divided at a "Y" connector into two tubes, one for antegrade delivery and one for retrograde delivery. The control switch has a prime position with both divided tubes open. Movement from prime position to an operative position is irreversible. In the operative position, there is an "off" position with both tubes closed, an antegrade position with the antegrade tube open and the retrograde tube closed, and a retrograde position with the retrograde tube open and the antegrade tube closed. Movement from one position to the other requires movement through the "off" position so there can be no cross-flow from antegrade to retrograde. Pressure monitoring tubes are incorporated into the switch to be opened and closed with the respective tubes.