非青色性先天性心疾患に於ける色素稀釈法の検討

On the dye dilution curve in acyanotic congenital heart diseases

　従来，色素稀釈法は心肺機能検査法の一つとして心搏出量，平均肺循環時間，肺血量等の測定に用いられて来たが，先天性心疾患に於いては心臓内或いは大血管の血液異常短絡を有するため色素濃度曲線は著しく変形し，而も右→左，左→右と云う2つの異つた短絡の様式により夫々特有な形を示すことから，本法を診断の一手段とする試みがなされて来た。即ちKnutson^1）（1950）は初めて先天性心疾患に色素法を適用し，右→左短絡を有する患者では色素出現時間の早い二峯性曲線を示すことに注目した。其後Nicholson^2），Swan^3），Wood^4）等により先天性心疾患の診断，短絡量測定のために，又Roe Arellano^5）により左→右短絡性疾患の肺血流量測定のため検索されて来た。著者等も数年来心カテーテル法と共に色素稀釈法を施行して来たが，本稿では動静脈性短絡を有する所謂非青色性先天性心疾患に就いて色素濃度曲線の特徴，短絡血流量との関係を検討し，合せて診断的価値について考察を加えた。

The dye dilution curve of acyanotic congenital heart disease with left to right shunt was studied in 12 patients who had atrial septal defect, ventricular septal defect or patent ductus arteriosus, and was comp-ared with that of 40 cases without the shunt.

The characteristic of the curve of acyanotic congenital heart disease was an increase of the ratio of dis-appearance time to build up time (D. T. /B. T.) and a decrease of peak concentration (P. C. ). D. T. /B. T. showed a significant positive correlation (r = O.801) with the ratio of left to right shunt, and P. C., though less significant than the former, also showed a negative correlation (r = -O.602) with the ratio of the shunt. D. T. /B. T. was less than 4.8 in all cases without the shunt, while in cases with the shunt D. T. /B. T. always exceeded 4.8 when the shunt showed over 40%. It was, consequently, concluded that D. T. /B. T. is valuable for diagnosis of the shunt and determination of its ratio in congenital heart disease with the shunt over 40%. P. C. showed a considerably large variation in cases without shunt, so that only in cases with the shunt over 60% P. C. had a diagnostic value.