Transcapillary escape rate of albumin and right atrial pressure in chronic congestive heart failure before and after treatment.

The transcapillary escape rate of albumin (TERalb), i.e., the fraction of intravascular mass of albumin that passes to the extravascular space per unit of time, was determined from the disappearance of intravenously injected 125I-labeled human serum albumin during the first 60 minutes after injection in 10 subjects with chronic right heart failure. The investigation was repeated after sodium and water depletion. Before treatment TERalb was significantly elevated (mean 8.3 +/- 1.6% (SD)/hour, in comparison to values for normal subjects (mean 5.4 +/- 1.1%/hour, P less than 0.001). With treatment TERalb decreased significantly (mean 5.9 +/- 1.2%/hour, P less than 0.01). Right atrial pressure decreased from an average of 10 mm Hg to 6 mm Hg during treatment. A statistically significant, positive correlation was found between TERalb and right atrial pressure (r = 0.77, P less than 0.001). Our results best can be explained by increased filtration, mainly through the venous end of the microvasculature, due to the increased venous pressure in heart failure.