Effect of right atrial appendicectomy on the release of atrial natriuretic peptide in humans.

The present study evaluated the effect of right atrial appendicectomy on the release of atrial natriuretic peptide (ANP) and subsequent changes in postoperative haemodynamics in 20 men undergoing coronary artery bypass graft surgery. The right atrial appendix was removed in ten patients and saved in ten. Serum ANP, sodium levels and urinary sodium excretion were measured before and on days 1, 7 and 30 after surgery. Haemodynamic parameters were monitored before surgery and on day 30. Serum ANP levels fell significantly in patients undergoing appendicectomy (P < 0.05); haemodynamic parameters were unchanged. Hence, appendicectomy reduced serum ANP levels in the short term, though these tended to rise again with time; cardiac function was not affected by lowered levels of serum ANP. Consequently, saving the appendix in right atrial appendicectomy improves natriuresis and may decrease diuretic requirement.