Hemodynamics of the splanchnic and systemic circulation after hypotonic water load-comparison between normal subjects and patients with congestive heart failure

The authors investigated the changes in cardiovascular and splanchnic hemodynamic, diuresis and urinary and hepatic veins osmolarity induced by hypotonic water load in five normal subjects and in five patients with congestive heart failure (CHF). Pulmonary wedge pressure increased significantly only in CHF patients while cardiac index, total pulmonary resistances and peripheral vascular resistances remained unchanged in both groups. Hepatic blood flow increased significantly in control group while in CHF showed a significant reduction 15 and 30 minutes after water load. Hepatic veins osmolarity decreased significantly in control group only at the 45th minute. Diuresis was significantly higher in normals which eliminated water load with a lower urinary osmolarity. The authors conclude that: water loading is particularly interesting in so much it resembles the physiological conditions of the absorption of the alimentary hypotonic bolus; the failing heart responds to the water load on a depressed function curve; the hepatic blood flow is reduced in CHF patients and is probably responsible for some humoral abnormalities found in these subjects; CHF patients eliminate a water load slower than a normal subject and with a higher osmolarity.