Poly-plethysmographic study on the effects of ritodrine on the cardiovascular system of patients in labour.

The effects of ritodrine infusion on the cardiovascular system of six women in threatened or premature labour are reported. In contrast to other betamimetics, ritodrine caused a moderate rise in systolic blood pressure, the corresponding fall in diastolic pressure leading to a widened pulse pressure but no risk of hypotension. Ritodrine caused a rise in cardiac output, and was well tolerated by the patients. Special care should be taken in treating patients with known heart disease.