The aim of investigation was to study the disturbances of left ventricular (LV) systolic and diastolic function of the heart in patients with chronic heart failure (CHF), coronary and non-coronary origin. 121 patients with CHF II–III stages were studied by cardiosynchronized equilibrium radionuclide ventriculography at rest on gamma camera LFOV–IV. In 78 patients CHF developed due to ischemic heart disease (IHD), in 43 – as a result of dilated cardiomyopathy (DCM). The control group consisted of 16 healthy subjects. The study was performed with 99mTc-pertechnetate (375–430 MBq tracer dose). In IHD patients with IIA stage CHF more severe diastolic
dysfunction and less severe disturbances of LV systolic function were observed, compared to patients with DCM. Along with progression of heart failure (stages IIB–III) in patients with coronary and non-coronary etiology
of CHF, differences in the degree of systolic dysfunction decreased. Patients with DCM and IIB–III stages of CHF failure are characterized by more severe LV diastolic dysfunction. Analysis of this index in patients with severe left ventricular systolic dysfunction may serve an additional criterion for differential diagnosis of coronary and non-coronary genesis of CHF.