Apparatus and method for evaluating cardiac functions

An esophageal probe useful for invasively monitoring the cardiac output of a patient generally comprises a chassis with an electrical cable extending from the proximal end of the chassis and with the cable terminating at an electrical plug configured for connection to a cardiac output monitor. The probe includes an electrode assembly configured to generate and transmit electrical signals that are indicative of the impedance variation of the thorax. The probe further includes a deployment device attached to the chassis for stabilizing the probe within the esophagus. The probe may also be configured to include other sensing devices, for example, a temperature measuring device and an acoustic monitor.