Cardiovascular and respiratory effects of terbutaline in patients after open-heart surgery.

In 10 patients after mitral or/and aortic valve replacement, terbutaline was given intramuscularly (10 mcg/kg body wt.) to see what cardiovascular and respiratory effects were produced. A marked cardiovascular effect was seen. Increase in heart rate (20%) was of sinus or atrial origin, no ventricular arrhythmias were seen. Cardiac index rose (46%) left and right stroke work increased (18%, 31%); systemic and pulmonary vascular resistance decreased (32%, 19%); Arterial oxygen tension decreased from 134 to 102 mmHg (24%); O2-consumption remained unchanged. Except for an increase in compliance no changes in respiratory dynamics occurred in the total respiratory system. Terbutaline's cardiovascular effects, its low toxicity, lack of ventricular arrhythmias and unchanged oxygen consumption, indicate that it could be useful to patients where an increase in cardiac output and improvement in peripheral circulation is needed.