Increased secretion of atrial natriuretic polypeptide in response to cardiac pacing.

Effects of cardiac pacing on secretion of atrial natriuretic polypeptide (ANP) were examined in 20 patients during cardiac catheterization under control conditions. The plasma ANP concentration in the coronary sinus (900 +/- 115 pg/ml) was significantly higher than those in the aorta (147 +/- 19 pg/ml) and the femoral vein (105 +/- 15 pg/ml) (p less than 0.001). The plasma ANP concentration was also significantly higher in the aorta than in the femoral vein (p less than 0.001). Its concentration at all three sites significantly increased during cardiac pacing (from 900 +/- 115 to 1461 +/- 218, from 147 +/- 19 to 250 +/- 36, and from 105 +/- 15 to 150 +/- 24 pg/ml, respectively). However, mean right atrial pressure and mean pulmonary capillary wedge pressure showed no significant changes between control conditions and during pacing (5 +/- 1 vs 6 +/- 1, and 8 +/- 1 vs 8 +/- 1 mmHg). Furthermore, there was no significant correlation between ANP secretion and the pressure in both atria. Thus, cardiac pacing can release ANP from the heart without increasing atrial pressure.