Antianginal and haemodynamic effects of a new beta-blocking agent, SD 1601

Seventeen patients suffering from angina pectoris were submitted to bicycle ergometer test until an ST ischemic segment of typical pain occurred. Before and during the effort the ECG was recorded: before and after the exercise, the systolic intervals were calculated and arterial pressure measured. The T.P. index, namely the product of systolic arterial pressure by the heart rate and ejection time was calculated. The recordings and the effort test were repeated 5 min after treatment with the beta-blocking drug 1-(o-methoxyphenoxy)-3-isopropylamino-2-propanol hydrochloride (SD 1601). After treatment with the blocker, patients were able to prolong the duration of exercise or perform a higher mean total external work. SD 1601 significantly diminished O2 myocardial consumption at rest, expressed as T.P. During physical exercise, work and thus O2 consumption rise; given equal external work, SD 1601 rduces significantly O2 consumption. Acutely given, SD 1601 did not affect systolic intervals nor did it exert any negative inotropic effect.