EFFECT OF PARTIAL ATRIAL APPENDECTOMY ON CIRCULATING ANF LEVELS AND RENAL SODIUM AND WATER-EXCRETION IN PATIENTS UNDERGOING AORTOCORONARY BYPASS-GRAFTING

Human ANF is produced predominantly in the appendage of the right atri um. The hormone is released by atrial stretching. ANF release results in an increase in renal filtration and blood flow. Sodium excretion is exaggerated and sodium reabsorption is inhibited. Consequently, there is an increase in diuresis.The question of this study was whether ven ous canulation through the right atrial appendage with partial removal of it during aortocoronary bypass operation results in a significant reduction of serum ANF with a subsequently reduced natriuresis and diu resis. Therefore, 20 patients undergoing aortocoronary bypass grafting (normal left ventricular function, normal renal function) with (n = 1 0) and without (n = 10) partial atrial appendectomy were examined conc erning h-ANF plasma levels, the content of h-ANF in the removed atrial appendage, renal sodium and water excretion. Samples were taken at th ree different times: before, during and 3 h after cardiopulmonary bypa ss. There was no significant difference between the two groups concern ing all parameters investigated. Although there was a tendency for an increased urine and sodium excretion in the group without atrial appen dectomy during cardiopulmonary bypass (not significant), these differe nces disappeared in the early postoperative phase. It is concluded tha t partial atrial appendectomy during aortocoronary bypass grafting has no influence on sodium and water regulation in the early postoperativ e phase.