Background: Sevoflurane and ketamine are commonly used to obtain sedation and facilitate intravenous anesthetic induction in children undergoing cardiac surgery who are uncooperative. We used a new and direct systemic hemodynamic monitoring technique pressure recording analytical method and compared the hemodynamic effects of sevoflurane and ketamine to facilitate intravenous anesthetic induction. Methods: Forty-four children with ventricular septal defect (2.2 +/- 1.2 years) were enrolled and randomized to receive sevoflurane (Group S) or intramuscular ketamine (Group K) for sedation, followed by intravenous midazolam-sufentanil induction and tracheal intubation. Recorded parameters included heart rate (HR), arterial pressures, stroke volume index (SVI), cardiac index (CI), systemic vascular resistance index (SVRI), the maximal slope of systolic upstroke (dp/dt(max)) after sedation obtained with sevoflurane or ketamine, 1, 2, 5minutes after midazolam-sufentanil, 1, 2, 5, and 10minutes after tracheal intubation. Rate-pressure product (RPP) and cardiac power output (CPO) were calculated. Results: As compared with Group S, Group K had faster decreases during intravenous anesthetic induction in arterial pressures (P<.01 for all), higher HR, arterial pressures, SVRI, dp/dt(max), RPP, lower SVI, CI, CPO (P<.05 for all) during the study period. Conclusion: As compared with sevoflurane, ketamine facilitated intravenous anesthetic induction exerts unfavorable effects on systemic hemodynamic and myocardial energetic in children with ventricular septal defect.