Hemodynamic effects of arteriovenous fistulae in chronic hemodialysis patients at rest and during exercise.

The effects of arteriovenous fistulae (AVF) on cardiac output (CO) and cardiac filling pressures were studied at rest and during exercise in 16 chronic hemodialysis patients. After the occlusion of the AVF, average CO fell but cardiac filling pressures remained unchanged, seven patients had a drop in CO greater than or equal to 1.0 l/min (group A) and nine patients had a drop in CO less than or equal to 0.9 l/min (group B). At rest, average CO was higher in group A than in group B, but cardiac filling pressures were the same in group A and in group B. During maximal exercise, average CO and cardiac filling pressures were the same in both groups.