New thermo-couple copper constantan catheter for measuring regional coronary blood flow and evaluating metabolism

A new thermodilution catheter with a thermo-couple copper constantan and la tex balloon in the tip has recently been developed. This device has two ori fices. The [eft anterior descending (LAD) and/or left circumflex (LCX) flow s were measured using a Doppler flow, wire. The correlation between the LAD and GCV flow as well as between the LCX and CS-GCV flow were studied in cl osed chest animals. The flow distributions were evaluated by colored micros pheres that were infused into the LAD and LCX. The regional lactate extract ion ratio was measured by GCV and/or CS blood sampling performed either wit h or without balloon inflation before and during pacing in either LAD or LC X occluded animals. The correlations between the LAD and GCV flow, as well as between the LCX and CS-GCV flow were significant (r=0.96, r=0.93, n=30, p <0.001). The flow distribution by color microspheres in the GCV was 75 +/ - 10% for the LAD, whereas in CS it was 70 +/- 12% for the LCX. By pacing, the lactate extraction ratio of the drained blood from the ischemic myocard ium was +10 +/- 3% in the GCV blood, whereas it was -10 +/- 4% (p <0.01) in the CS blood. Thus, this new thermodilution catheter with a balloon was fo und to be useful for measuring regional coronary hemodynamics and also for evaluating the regional myocardial metabolism.