RESUMEN
<p><b>AIM</b>To introduce a new device and catheter to be determining cardiac output through cor sinistrum with thermodilution.</p><p><b>METHODS</b>Own control was introduced in eight dogs. A pulmonary thermodilution catheter was used through the cor dextrum of the dogs; The new-design catheter was used through artery, and there were two situs to fix:its ahead in left atrium and the ahead near to aortic root. Determine cardiac output (CO) under four circumstances: controlled respiration, apnoea, in controlled hypotension, after controlled hypotension.</p><p><b>RESULTS</b>There was no significant difference among the parameters (CO and cardiac index) of all circumstances. The CO determined by the pulmonary thermodilution catheter and those by the new-design catheter in two situs were positive correlation, and the gamma were 0.986, 0.989; likewise, the cardiac index (CI) was positive correlation, and the gamma were 0.983, 0.985. The CO and CI by the new-design catheter between two situs were positive, and the gamma were 0.992, 0.988.</p><p><b>CONCLUSION</b>The parameters by the new-design catheter and those by the pulmonary thermodilution catheter were concordant. In comparison with the pulmonary thermodilution catheter, the new-design catheter had simple device and could be easily operated.</p>