The article presents clinical observation of the patient after allotransplantation of the cadaveric kidney with functioning arteriovenous fistula (AVF). At the time of admission, there was a severe congestive heart failure (CHF) with preserved graft function. During the examination, severe symptomatic aortic stenosis (AS) and clinical and instrumental signs of heart failure with high cardiac output (HFHCO) due to a long-functioning AVF with excessive blood flow were detected. For the objectification of the CHF genesis, temporary occlusion of AVF during echocardiography (EchoCG) and during the catheterization of the right heart was performed. The results of the examination made it possible to clarify the specific hemodynamic model of AS (high gradient/high blood flow) and to formulate indications for ligation of AVF. After surgical closure of the vascular access, the signs of CHF completely resolved within 10 days. The control EchoCG confirmed the reduction of pulmonary hypertension and an improvement in the left ventricle diastolic function. Ligation of AVF allowed to establish a real severety of AS (severe asymptomatic) and determine the urgency of surgical correction of the defect. A diagnostic algorithm for examining patients with AS and functioning AVF, which allows to determine the true severity of the defect and to assess the presence and hemodynamic severity of the concomitant HFHCO, is discussed. A brief literature review is presented.

Keywords: ligation of arteriovenous fistula, temporary occlusion of arteriovenous fistula, heart failure with high cardiac output, calcific aortic stenosis, kidney transplantation