Cardiovascular system is severely influenced with chronic renal failure. Although dialysis and renal transplantation have been improved the survival of the patients with chronic renal failure in past 30 years, but cardiovascular disease is the most common cause of their death yet. Dialysis could regress many of the changes    accompanied with chronic renal failure, if begins soon enough .

          This study was an analytical time series study that 40 patients with chronic renal failure that were on maintenance dialysis, were studied by echocardiography, before and after one of their dialysis cession and left ventricular Ejection Fraction (EF) of before and after and the results were compared.

          The mean of EF before and after echocardiography were 58.08% 9.8 and  64.678.01 respectively. After analysis with Paired samples test, this difference was obviously significant (P=0.00).

          It was concluded that hemodialysis can increase the left ventricular ejection fraction in hemodialysis patients.