Baroreflex loading via 30-degree head-down tilt failed to suppress elevated baseline arginine vasopressin levels (6.5 +/- 2.0 pg/ml) in patients with congestive heart failure.
Does baroreflex loading via head-down tilt suppress increased plasma arginine vasopressin levels in patients with congestive heart failure?
Patients with chronic congestive heart failure exhibit an abnormality in baroreflex suppression of arginine vasopressin secretion, potentially contributing to chronically elevated levels.
Nonspecific baroreflex loading maneuvers such as head-down tilt readily suppress stimulated arginine vasopressin levels in normal humans. To test the hypothesis that the increased arginine vasopressin levels in patients with congestive heart failure would not respond normally to baroreflex loading, 12 patients with congestive heart failure had arginine vasopressin levels and osmolality determined in the supine position and after 15 min of 30 degrees head-down tilt. Arginine vasopressin was increased to 6.5 +/- 2.0 pg/ml at control measurement and did not decrease. Eight patients underwent further study after osmotic stimulation with mannitol. Mannitol increased osmolality from 287 +/- 9.2 to 294 +/- 7.8 mOsm/kg (p less than 0.001) and from 288 +/- 9 to 299 +/- 8.2 mOsm/kg (p less than 0.01) on two occasions. No significant suppression of arginine vasopressin was seen during head-down tilt after mannitol infusion compared with values in a time control period. These results are consistent with an abnormality in baroreflex suppression of arginine vasopressin secretion in chronic congestive heart failure and suggest that such a defect may contribute to long-term high levels of arginine vasopressin in this condition.
Steven R. Goldsmith（周五）在充血性心力衰竭中（n=12）进行了其他研究。评估了动脉压反射负荷操纵（30度头低位倾斜）和甘露醇对平卧位置/时间对照期在精氨酸加压素水平上的影响。通过30度头低位倾斜施加动脉压反射负荷未能抑制充血性心力衰竭患者中升高的基线精氨酸加压素水平（6.5 +/- 2.0 pg/ml）。