Abstract: A system for achieving cardioplegia, a protective cessation of the heart muscle activity during open heart surgery which includes providing a circulation system in parallel with the main life support system and deriving a blood source from the arterial reservoir of the main life support system, moving blood from said source through a cooling heat exchanger for selective discharge to the aorta of the heart patient or to a cardiotomy reservoir in the main life support system. The system includes a means for titration of medication to the blood and temperature control and monitoring equipment.

Abstract: A method and device for connecting a life support machine to the heart of a patient during open heart surgery which includes a two-stage venous return catheter having spaced inlet openings in the tip end and spaced from the tip end to insure proper connection to the various cavities of the heart and adequate return flow for a life support machine.

Abstract: A temperature probe and connector for extracorporeal monitoring of blood by-passed from a patient undergoing open heart surgery which includes a conductive connector unit interposed in the by-passed blood tube and a probe removably mountable on said connector unit having a sensing element for a telethermometer, said probe assembly being manually mountable and demountable on the connector unit and designed to cooperate with the connector unit to sheath the conductive connector tube to isolate it from ambient temperature.