ATRIAL-NATRIURETIC-PEPTIDE SECRETION AND BODY-FLUID BALANCE AFTER BILATERAL ATRIAL APPENDECTOMY BY THE MAZE PROCEDURE

Objectives: One of the earliest recognized postoperative complications of the maze procedure was the fluid retention in the immediate postop erative period. Routine postoperative administration of diuretics mark edly reduces the frequency and severity of the fluid retention. Howeve r, the cause of the abnormal fluid balance is still uncertain. Methods : We evaluated 24 patients: 15 patients underwent the maze procedure ( maze group) and 9 patients did not (nonmaze group). Blood samples were obtained before and in the time course after operation for atrial nat riuretic peptide measurement. To evaluate the influence of atrial natr iuretic peptide on the body fluid balance, we also measured the amount of body fluid balance and the total doses of furosemide and dopamine administered after operation. To examine the effect of the maze proced ure on atrial natriuretic peptide secretion in chronic phase, we measu red plasma atrial natriuretic peptide levels during dynamic exercise i n 21 patients who had undergone cardiac operations 2 years before, Res ults: Plasma atrial natriuretic peptide levels in the nonmaze group si gnificantly increased after operation. In contrast, plasma atrial natr iuretic peptide levels in the maze group did not increase, and these l evels were significantly lower than in the nonmaze group, Although sig nificantly greater doses of furosemide and dopamine were administered to the maze group than to the nonmaze group, the body fluid balance in the maze group was comparable with that in the nonmaze group in the e arly postoperative period. The response of atrial natriuretic peptide secretion by exercise was significantly attenuated in the maze group ( n = 12) compared with the nonmaze group (n = 9) even 2 years after sur gery, although there were no significant differences in heart rate or blood pressure during exercise between two groups, Conclusions: These results suggest that the maze procedure attenuates atrial natriuretic peptide secretion in the early postoperative period and persists in ch ronic phase. This attenuated atrial natriuretic peptide secretion may reduce the ability of the kidneys to handle fluid load early after sur gery.