In right ventricular failure (RVF) a decrease of right ventricular afterload and improvement of left atrial filling could be achieved by a pulmonary artery-left atrial (PA)-shunt. To avoid cyanosis, artificial oxygenation is necessary. In 11 pigs a PA-shunt was created. An interventional lung assist device (ILA) was installed from the femoral artery to vein in 5 pigs (serial in relation to native lung: Group I) and into the PA-shunt in 6 pigs (parallel: Group II). RVF was induced by pulmonary artery banding. Right ventricular performance was determined by pulse contour analysis, pressure - and flow measurements. In both groups a stable RVF was generated. In Group I cardiac output trended to increase but neither right ventricular filling pressures nor arterial pressure changed significantly. The PaO2 decreased significantly. In Group II cardiac output and arterial pressure increased significantly under a shunt flow of 2.3- 2.6 l/min and the animals recovered from cardiogenic shock. In conclusion a PA-shunt with a parallel lung assist can effectively reverse the deleterious effects of RVF.