A new orally active positive inotropic substance: AR-L 115 BS

In the course of diagnostic cardiac catheterisation in 6 patients suspected of having coronary heart disease 2-[(2-methoxy)-4-methylsulfinyl)phenyl]-1H-imidazol[4,5-b]pyridine (AR-L 115 BS) was administered to see whether an improvement in left ventricular function could be achieved. 30 min after oral administration of the drug there was an increase in the ejection fraction (EF) and in the rate of circumferential fibre shortening (FSR) and a decrease in the end-systolic volume (ESV) and end-diastolic pressure (EDP). There was no significant change in heart rate (HR) and systolic blood pressure. The investigation confirmed the positive inotropic effect of AR-L 115 BS following oral administration: this substance could, therefore, be of value in the treatment of cardiac insufficiency.