Effects of Injection Site on the Accuracy of Thermal Washout: Discussion (2)
However, by analyzing thermal washout curves obtained in patients, we observed that successive EFs increased in RA injection and that EF3 was small in RV injection. A similar phenomenon was observed in the model experiment when the indicator was injected just above the inflow valve (above the tricuspid valve); EF2 was the largest and closest to the mechanically predetermined value. When injection into the chamber (ventricle) was performed directly, EF1 or EF2 was the largest and closest to the mechanically predetermined value and the successive decrease was apparent with a preset EF/stroke of 0.62/60 (Table 3). proventil inhaler
With a preset EF of 0.62, the residual cold energy in the chamber after the first and second ejections was small. A small temperature change could be possibly affected by the cooled chamber, and thereby the resultant temperature change might be falsely exaggerated and EFs would be successively underestimated. However, this phenomenon could not be detected in EFs of 0.40 and 0.44, in either of the inflow circuit or chamber injections, possibly because the residual temperature change may have been relatively large compared with the small temperature change caused by potential cooling of the chamber wall. This may be the reason why this phenomenon has been overlooked by researchers.