A new method reflecting hemodynamic and myocardial contractility patterns during heart surgery under extracorporeal circulation was used in 11 patients, with a total of 89 measurements performed. PV-diagram enables a real-time assessment of the heart's pumping function with reference to specific phases of the cardiac cycle, and also a prompt visual dynamic assessment of the circulatory status. The method can be efficient in the evaluation of the effect of corrective heart surgery.