Echocardiographic evaluation of vagolytic effects of hyoscine butylbromide in paediatric halothane anaesthesia.

The effects of vagolysis with hyoscine butylbromide on left ventricular function were evaluated by echocardiography during halothane anaesthesia in children. Echocardiography showed deterioration of the following values after halothane induction; pre-ejection period, systolic time interval, left ventricular shortening fraction and ejection fraction. The first two values were improved by vagolysls with hyoscine butylbromide. However, relatively rate-independent indices, i.e. left ventricular shortening fraction and ejection fraction, still remained depressed even after vagolysis with hyoscine butylbromide. This implies that halothane-induced myocardial depression can only be partially antagonized by vagolysis.