CENTRAL HEMODYNAMIC-EFFECTS OF COCAINE AND RITODRINE IN THE ISOLATED,PERFUSED RAT-HEART

Objective: To explore the cardiac interactions of cocaine and ritodrin e in pregnancy. Methods: Using the isolated, perfused rat-heart model, hearts from pregnant Sprague-Dawley rats were exposed to increasing c oncentrations of ritodrine: 25, 50, 100, and 250 ng/mL. Hearts of half of the animals, the experimental group, were exposed to cocaine (5 x 10(-6) mol/L). Left ventricular systolic pressure, heart rate, and con tractility were measured. Results: Ritodrine had marked positive inotr opic and chronotropic effects. Cocaine exposure resulted in smaller in creases in all indices. Conclusion: Cocaine blunted but did not oblite rate the cardiac stimulatory effects of ritodrine in this model. (Obst et Gynecol 1994;83:89-91)