Evaluation of the ECOM™ Monitor for Continuous and Non-invasive Measure of the Cardiac Output in Cardiac Surgery Patients

Inclusion Criteria: * Patients over18 years * Needed cardiac surgery, * Needed a monitoring by transesophageal ultrasound , * Benefiting from a social security scheme * Having given their written consent. Exclusion Criteria: * Pregnant or breast-feeding women, * Allergy to polyvinylchloride (PVC), * The patients for whom a difficulty of ventilation with a mask or intubation is envisaged, * Contraindication to transesophageal ultrasound, a steady cardiac arrhythmia, a flight or an aortic shrinkage.