The pulmonary artery pressure can also increase due to high cardiac output (resulting from the arteriovenous access itself and often concomitant anemia) as well as fluid overload.[8] Studies on the role of parathyroid hormone have provided conflicting data.[1, 9] The duration of arteriovenous fistula and flow through it have been correlated with high incidence of PHT.[9] Diastolic and systolic dysfunction of the left ventricle frequently seen in renal failure can also contribute to pulmonary hypertension.[10]. This evidence concerns the gene PTH and Renal insufficiency.