Fig. 3. Ensemble of hemodynamic changes after the administration of oxytocin. ( A ) Heart rate (HR). At peak effect, HR increased from 84.7 (12.6) to 101.5 (15.9)* beats/min. ( B ) Mean arterial pressure (MAP). At peak effect, MAP decreased from 114.3 (15.0) to 80.6 (15.3)* mmHg. ( C ) Stroke volume (SV). At peak effect, SV increased from 82.9 (15.9) to 89.1 (17.3) (not significant). ( D ) Cardiac output (CO). At peak effect, CO increased from 7.0 (1.5) to 9.1 (2.3)* l/min. ( E ) Systemic vascular resistance (SVR). At peak effect, SVR decreased from 1,295 (252) to 718 (282)* dyn · s · cm−5. * Value significantly different from baseline and postdelivery; P < 0.01 .