[The value of xamoterol in moderate ischemic cardiac insufficiency]

Xamoterol is a partial beta-1 adrenergic agonist capable of stabilising the beta-1 receptor to 43% of their maximal activity. Xamoterol was administered to 10 patients with moderate ischaemic heart failure at an oral dose of 200 mg twice a day. After 3 months, there was an improvement in left ventricular function: 28% reduction in the end-diastolic pressure (p less than 0.01), 12% reduction in ventricular volume (p less than 0.05) with a marked increase in the inotropic state. The exercise tolerance was also increased (+ 30 watt; p less than 0.05) and several indices suggest an improvement in myocardial metabolism. In conclusion, xamoterol is a positive inotrope which does not present the phenomenon of tachyphylaxis during the prolonged administration.