New Approach to Circulatory Assist: Left Heart Bypass (LHB) and Synchronized Coronary Sinus Retroperfusion (SCSR)

Abstract

To evaluate the efficacy of the concomitant use of left heart bypass (LHB) and synchronized coronary sinus retroperfusion (SCSR), we carried out experimental studies in swine, comparing concomitant LHB and SCSR with the concomitant use of intra-aortic balloon pumping (IABP) and LHB as a conventional circulatory assist. A cardiogenic shock model was prepared by the left anterior descending coronary artery (LAD) ligation method. LHB was performed with a centrifugal pump. Arterial blood was pumped to the coronary sinus (CS) from the femoral artery by SCSR. The IABP was inserted from the femoral artery. The animals were supported by SCSR, LHB, IABP + LHB, and SCSR + LHB, and cardiac performance, infarcted area, and coronary flow were compared for each modality. Infarcted areas were evaluated by epicardial mapping electrocardiogram (e-ECG). Coronary blood flow and velocity were analyzed with an electromagnetic flow meter (EMF Nihon Kohden, Tokyo, Japan) and an ultrasonic pulsed Doppler velocimeter (UPD Triton, USA), respectively. In the SCSR + LHB group, the ischemic area was significantly reduced, by 12.5% of the shock level (from 181.1 to 22.7 mV). There were no significant differences in cardiac function between the IABP + LHB and SCSR + LHB groups. However, the reduction of the infarcted area was superior in the SCSR+LHB group. In both concomitant groups, the systolic reverse wave of LAD velocity, which had increased due to cardiogenic shock, was remarkably reduced. These results suggested that this new approach of SCSR and LHB is suitable for bringing about recovery from severe coronary artery disease in which antegrade coronary perfusion cannot be employed.