BLOOD CARDIOPLEGIA INFUSION USING A RECIRCULATION TYPE CIRCUIT GENERATES BRADYKININ IN SIGNIFICANT AMOUNTS DURING OPEN-HEART-SURGERY

The single pass type (SP) of blood cardioplegia is commonly used in No rth America during open heart surgery. However the recirculation type (RC) of blood cardioplegia is still widely used in other areas includi ng Japan. Infusion blood cardioplegia using the latter technique often decreases the perfusion pressure. To determine the cause for this, bl ood levels of bradykinin (BK) were measured in cardiopulmonary bypass (CPB) and the 2 types of blood cardioplegic circuits. As the BK levels in the RC cardioplegia (>3,000 pg/ml) rose, the perfusion pressure de creased abruptly with the increase of the BK levels in the CPB circuit . With SP cardioplegia, the BK level was not increased either during c ardioplegia (p < 0.009) or CPB (p < 0.009), and the perfusion pressure was not decreased (p < 0.02). We concluded that the SP circuit is sup erior to the RC one because of the lesser production of BK and thus le sser fluctuation of perfusion pressure.