Saline-induced coronary hyperemia with continuous intracoronary thermodilution is mediated by intravascular hemolysis

Abstract Objectives To test whether local hemolysis is a potential mechanism of saline-induced coronary hyperemia. Background Absolute flow can be measured by intracoronary continuous thermodilution saline through the lateral side holes dedicated infusion cathete. A rate at 15–20 mL/min induces an immediate, steady-state, maximal microvascular vasodilation. The this hyperemic response remains unclear. Methods Twelve patients undergoing left and right catheterization were included. artery sinus selectively cannulated. resting thermodilution. Arterial venous samples collected from in five phases: baseline (BL); measurement (Rest, 10 mL/min); hyperemia (Hyperemia,saline 20 post-hyperemia (Post-Hyperemia, two minutes after cessation infusion); control phase (Control, during guide catheter 30 mL/min). Results Hemolysis was visually detected only centrifugated blood Hyperemia phase. As compared to Rest, both LDH (131.50±21.89 U/dL [Rest] 258.33±57.40 [Hyperemia], p<0.001) plasma free hemoglobin (PFHb, 4.92±3.82 mg/dL 108.42±46.58 significantly increased sinus. percentage higher (0.04±0.02% vs 0.89±0.34% p<0.001). Conclusions Saline-induced associated with hemolysis. Vasodilatory compounds released locally, like ATP, are likely ultimately responsible for localized Funding Acknowledgement Type funding sources: None.