Myocardial tissue fluid flow (MTFF) directly represents the oxygen supply to the cardiomyocytes. Therefore, imaging of MTFF is carried out by fluorescence cardioscopy (FC).
Sixty-six patients with coronary artery disease underwent FC using fluorescein as an indicator of MTFF because this dye exhibits fluorescence in tissue fluid but not in the blood. Three mL of 10% fluorescein was injected intravenously and fluorescence images of the left ventricular endocardial surface were obtained by FC at 30 seconds and 1, 3 and 6 minutes later to evaluate the MTFF.
The CF images were classified as follows: diffuse with high intensity indicating normal MTFF; diffuse but with low intensity indicating decreased MTFF, no fluorescence indicating absent MTFF, and patchy fluorescence indicating patchy preservation of MTFF. MTFF was normal in all 18 patients with chest pain syndrome, patchy fluorescence was decreased or absent in 16 of 20 patients with angina and/or old myocardial infarction due to organic coronary artery disease, and was patchy in 21 of 28 patients with vasospastic angina. Ten of these 20 patients underwent coronary stenting with successful angiographic results in all. However, MTFF disturbance frequently remained.
FC is clinically feasible for evaluation of MTFF disturbance, for evaluation of even emergency coronary interventions, and for guidance of transendocardial angiogenic and myogenic therapies in patients with coronary artery disease.