Medical devices incorporating sensors, systems, and related methods

A method of determining cardiac output of a patient, the method comprising:

• inserting a flexible, elongated member into a vein of a patient;
• locating a distal end of the flexible, elongate member near a cavoatrial junction of the patient;
• passing a fluid through a lumen of the flexible, elongated member and through an exit port of the flexible, elongated member;
• determining a temperature of the fluid using a first sensor associated with the flexible, elongated member;
• measuring a time period that it takes for a second sensor associated with the flexible, elongated member to record a temperature that correlates with the determined temperature of the fluid;
• determining a flow characteristic based on a known distance between the first sensor and the second sensor and the measured time period.

A system comprising:

• a medical device comprising:
• a flexible, elongated member configured for insertion within a body such that a distal end may be positioned at or near a cavoatrial junction of a patient, the flexible, elongated member having a proximal end, and at least one lumen extending along a length of the flexible, elongated member;
• at least one sensor coupled disposed at the distal end of the flexible, elongated member;
• an external device in wireless communication with the medical device and configured to receive data from the at least one sensor.