The complex relationship among arteriovenous access, heart, and circulation.

There are currently near 400 000 patients on hemodialysis in the United States. More than 50% of those treated by chronic hemodialysis die because of a cardiovascular (CV) event. The majority of these patients have functional arteriovenous fistulas (AVFs). AVFs have an adverse effect on cardiac function, but their exact contribution to CV morbidity is not clear. It has long been known that a vascular access with an inappropriately high-flow rate may cause high-output heart failure. Paradoxically, there may be hemodynamic and cardiopulmonary benefits conferred by AVF particularly in severe chronic obstructive pulmonary disease. While Brescia-Cimino`s basic idea of the AVF has saved millions of lives, we would like to stress that there are dangers from their often high blood flow rates, which unfortunately have proved difficult to evaluate.