The Effects of the Anti Nausea Drugs Droperidol and Ondansetron on the Way the Heart Recovers Between Beats

We are investigating a new technique for testing the effect of drugs on electrical activity in the heart. Disturbances of this electrical activity can cause life-threatening changes to heart rhythms. A better way of measuring the risk has recently been developed, and our research team leads the world in using this tool to test the safety of drugs used in children. Children and their families want to know that the drugs being used are safe, as do the doctors that care for them. In this study, we will take heartbeat tracings (ECGs) from 60 children before and during their operations. The ECGs will then be checked by a children\'s heart specialist. Differences on the ECGs will be related to the presence and amount of drug (droperidol or ondansetron) given. We expect that the droperidol or ondansetron will not cause any changes that show increased risk of abnormal heart rhythms. We can then tell patients, parents and regulatory authorities of the safety profile of this aspect of the drug; moreover, the study can be used as a model for testing many other drugs used in hospitals.