[Patients on chronic hemodialysis. Hemodynamic study at rest and during exercise before dialysis, in hypertensive and normotensive patients (author's transl)].

In twenty chronic hemodialyzed patients a hemodynamic study was carried out just before dialysis at bed rest and during sitting bicycle exercise. At bed rest, cardiac index (mean +/- standard deviation = 5.2 +/- 1.1/mn/m2) and pulmonary wedge pressure (17.4 +/- 6.8 mmHg) were increased. At the highest level performed (60 ou 90 W) cardiac index increased in all patients and reached on average normal values as compared to normal sedentary subjects, but heart rate less increased than in normal subjects during maximum effort. These data suggest that these patients had no patent heart failure. Pulmonary wedge pressure was more increased in hypertensive patients (20.7 +/- 6.7 mmHg) than in normotensive patients (13.3 +/- 4.4 mmHg). Since cardiac index was similarly increased in both groups of patients the higher values of pulmonary wedge pressure in hypertensive patients could be related to either an increase in total blood volume, or a reduction in left ventricular compliance or an increase in cardiopulmonary blood volume.