Abstract: The left ventricular catheter is adapted to be inserted into the heart and has an upstream heater winding near the distal catheter tip. Pulses of regulated electrical energy triggered by the R-wave of an electrocardiogram are supplied to the heater winding on the catheter so that successive heat energy is generated and dissipated in the blood volume of the left ventricle during successive diastoles. A resistance thermometer is mounted downstream from the heater winding to measure successive temperature increases as the heart beats over a 5-10 second measuring period, whereby a exponential temperature rise is recorded. To cancel deviation of temperature readings caused by heat dissipation from the lead wire conductors bypassing the thermometer to the catheter heater, lead wire conductors are provided to an external dummy load heater winding for bypassing the thermometer.

Abstract: A thermodilution catheter having a proximal high frequency heating coil of fine wires, heat measuring thermocouples, and a distal resistance thermometer, all wound externally on a catheter for measuring arterial blood flow. The device also incorporates electrodes for electrocardiogram tracing.

Abstract: A thermodilution catheter having a distal high frequency heating coil of fine wires, heat measuring thermocouples, and a proximal resistance thermometer, all wound externally on a catheter for measuring blood flow in either the jugular vein or the left ventricle of the heart. The device also incorporates electrodes for electrocardiogram tracings.