Measurement of coronary sinus flow using transesophageal echocardiography undergoing coronary artery bypass grafting

Abstract

S237 INTRODUCTION: Transesophageal echocardiography (TEE) has been used during cardiac surgery worldwide. We hypothesized that the coronary sinus flow (CSF) increased after coronary artery bypass grafting. CSF calculation was performed with the use of TEE at rest patients [1]. We performed this study to assess the feasibility of measuring CSF and estimating changes in coronary sinus flow during coronary artery bypass grafting (CABG) by TEE. METHODS: After obtaining approval from the Protection of Human Subjects Committee of Jikei University Hospital and informed consent from each patient, 25 adult patients (ASA physical status 3 or 4) were enrolled as subjects of the study. After the induction of general anesthesia, the TEE probe was inserted into the patient's esophagus. Before the cardiopulmonary bypass (CPB) [control] and after CPB, we measured CSF using TEE and hemodynamic variables. RESULTS: 1) CSF was measured in 24 control subjects completely (96%, 24/25 patients; after CPB: 92%, 23/25 patients). 2) All velocities and velocity time integrals of CSF at systolic and diastolic increased significantly after CABG. 3) Heart rate (HR) and cardiac index (CI) increased and blood pressure decreased significantly after CABG. Coronary sinus diameter (CSD) and diastolic pulmonary artery pressure (PAD) were not changed significantly (Table 1).Table 1DISCUSSION: 1) CSF was measured completely in 96% of the subjects during CABG. However, it was difficult to position the sample volume adequately, because of the cyclic cardiac movement associated with positional changes of coronary sinus in the high HR case especially. 2) CSF increased significantly after CABG, which was probably due to increased coronary blood flow after CABG. The results of this study indicate the feasibility of this new perioperative method of CABG evaluation.