Background: Radionuclide ventriculography enables such parameters of the left ventricular (LV) function as the ejection fraction (EF), ejection rate (ER) and filling rate (FR) to be measured correctly. The impairment of the LV function in coronary artery disease (CAD) results in an increase in plasma brain natriuretic peptide (BNP). The aim of this study was to check whether the reduction of the average filling rate (AFR) leads to an increase in plasma BNP levels in patients with CAD and nEF and whether that increase is comparable to that occurring in subjects with a reduced PER.
Material and methods: The study population comprised 69 patients with CAD and 18 healthy subjects--a control group (CG). In all cases radionuclide ventriculography was performed at rest and the plasma BNP level was estimated.
Results: The plasma BNP concentration was significantly higher in the group with CAD than in those with CG . In patients with CAD and a decreased LVEF (dEF), the BNP level was significantly higher than in those with normal LVEF (nEF). In the subgroup with nEF and an AFR < or = 1.04 EDV/s, the level of plasma BNP was significantly higher than in that with an AFR >1.04. In the total CAD group, a significant correlation was found between plasma BNP concentrations and the LVEF, PER and AFR. In patients with nEF, the level of plasma BNP correlated only with the AFR.
Conclusions: It is concluded that the diastolic dysfunction of the left ventricle in patients with CAD leads to an elevation of plasma BNP concentrations despite the normal ejection fraction. A diastolic dysfunction of the left ventricle affects the BNP plasma concentration to a greater degree than a systolic dysfunction.