Attenuation of atrial natriuretic peptide response to sodium loading after cardiac operation

The effect of the maze procedure on the secretion of arginine-vasopressin and aldosterone

BACKGROUND

Excessive fluid retention is a serious complication after the maze procedure that cannot be totally explained by changes in levels of atrial natriuretic peptide. We therefore measured circulating levels of arginine vasopressin and aldosterone in patients undergoing the maze procedure to study their possible role in this postoperative complication.

METHODS

Serial arginine vasopressin and aldosterone levels were monitored for 72 hours in 11 patients after coronary artery bypass grafting and in 13 patients after the maze procedure. Hemodynamic data, urine output, fluid balance, and complications were recorded prospectively during the same period of time.

RESULTS

Plasma levels of arginine vasopressin and aldosterone were significantly higher in patients after the maze procedure when compared with patients after coronary artery bypass grafting.

CONCLUSIONS

This study documents that the maze procedure results in increased plasma arginine vasopressin and aldosterone levels and indicates that they, rather than atrial natriuretic peptide alone, participate in the excessive postoperative fluid retention that follows the maze procedure. We believe that these hormone elevations are most likely secondary to a temporary lack of response of the atrial baroreceptors. These results may explain the effectiveness of spironolactone therapy after the maze procedure.

Effect of the maze procedure for atrial fibrillation on atrial and brain natriuretic peptide

We studied plasma levels of atrial and brain natriuretic peptides at rest and after exercise before and after intracardiac surgery with and without the maze procedure in patients with chronic heart failure secondary to valvular heart disease. The present study found that an increased response of both cardiac natriuretic peptides is attenuated with resulting water retention after the maze procedure.