The following parameters were measured: Cardiac Output (CO), mean Pulmonary Arterial Pressure (mPAP), Pulmonary Vein Resistance (PVR), B-type natriuretic peptide (BNP) which is a heart failure protein marker, G6PD activity and transferrin receptor concentration in RBC pellets adjusted to total protein concentration and level of mRNA expression for G6PD gene in PMBC. The gene discussed is TFRC; the disease is heart failure.