Regional blood flow in human congestive heart failure

Despite the total-body consequences of congestive heart failure, little information is available on the distribution of cardiac output and regional-organ hemodynamics in this condition in humans. Technical and methodologic limitations probably account for the paucity of data in this area. Available data indicate that blood flow to the regions or organs studied, namely, the kidneys, hepatosplanchnic region, and upper limbs, decreases in proportion to the reduction in cardiac output. However, renal blood flow appears to be protected in human heart failure by a form of "autoregulation" during marked depression of cardiac output (less than 2.0 L/min/m2). Results of preliminary studies suggest that the regulation of regional-organ hemodynamics is disturbed in this human condition. Cardioactive drugs profoundly affect regional-organ hemodynamics independent of changes in central hemodynamics and cardiac output. The determination of regional blood flow responses in human heart failure will become more important as we expand our knowledge base of the pathophysiology of heart failure, learn more about local vascular control mechanisms, and pursue the potential therapeutic objective of selectively augmenting regional-organ hemodynamics and function.