The main goal of the study was the evaluation of the diastolic function ofthe left ventricle in patients qualified for AVR, as well as changes to this functionafter the procedure.The inclusion criteria were the following: significant AS, sinus rhythm,informed consent. Patients were excluded based on the following criteria: CAD,qualification for TAVI or Bentall-De Bono procedure, reoperation, AR, mitral valvedisease, endocarditis; arrhythmia. The patients were evaluated in four phases:preoperative, intraoperative, early and late postoperative. The clinical data wasgathered among others using MacNew and DASI questionnaires.The following conclusions were drawn. First, a substantial diastolicdysfunction in patients undergoing AVR is rare. Second, diastolic function is acomplex process and subject to dynamic changes. Third, an understanding of theintensity of the diastolic function can benefit the resource management of ICU.Fourth, a positive result of the AVR appears between the third and sixth monthsfollowing the procedure. Patients with a restrictive filling pattern should not bedisqualified from AVR. Women require an AVR later and the procedure bringshealth benefits sooner. The discussed dysfunction does not have an impact onclinical symptoms, fitness, or quality of life. PPM causes a delay in the reversedremodelling of the left ventricle. The evaluation of the end-diastolic volume andmass of the left ventricle can be enhanced through the indexing. Finally, theproposed mathematical model of the diastolic function of the left ventricle waspositively validated and can be used in further studies.