Does the oxygen tension of coronary sinus blood reflect myocardial oxygen tension?

ABSTRACT

Coronary sinus blood oxygen tension (CSpO2) and myocardial oxygen tension (MpO2) were measured sismsultaneously during cardiac ischemia and reperfusion. Oxygen tension was measured using a decrease (56.5) ñ 10.1%; P < 0.001) in MpO2. Reperfusin induced a rapid but transient increase (35.9 ñ 4.3%; P < 0.001) in CSpO2 above the basal state while MpO2 returned gradually to the basal state. These results indicate that CSpO2 is of little value for the detection of changes in myocardial oxuigen metabolism during the initial phase (seconds) of cardiac reperfusin