STUDIES OF CORONARY BLOOD FLOW BY MULTIPLE DYE DILUTION CURVES*

Abstract

The feasibility of identifying coronary blood flow by the indicator dilution technique was examined in 16 dogs (6 open chest and 9 closed chest experiments). One hundred seventy paired curves were obtained with densitometers from the coronary sinus (CS), pulmonary artery (PA), inferior vena cava (IVC), and the superior vena cava (SVC) in various combinations following left atrial (LA) or left ventricular (LV) injection. Paired curves were also obtained from the PA and LV following venous injection. Dye appeared 2.6 [plus or minus]0.3 (SEM) seconds earlier in the CS than in the IVC, and 6.8 [plus or minus] 0.8 seconds earlier in the CS than in the SVC. This information together with analysis of PA and LV primary and recirculation curves following venous injection makes it unlikely that indicator restricted to the coronary circulation can be isolated from that returning by other paths.