R 80123 is the Z-isomer of R 79595, is also a highly selective phosphodiesterase inhibitor. The fuction is similar to R 80122 (Revizinone). In vivo: The administration of Revizinone improved the haemodynamic profile with an increase in cardiac output, a decrease in systemic vascular resistance and a stable heart rate and mean arterial blood pressure. With regard to reconstitution of contractility and cardiac function Revizinone (E-isomer) is 10 fold more potent than R 79595 and nearly 100 fold more potent than R 80123 (Z-isomer). Revizinone significantly increases global LV function and systolic wall thickening in ischemic areas at doses greater than or equal to 0.16 mg/kg i.v.