The goal of this observational study is to Compare the performance of uncalibrated pulse wave contour analysis compared with transesophageal echocardiography (TEE) to assess response to a vascular filling test during beating-heart coronary artery bypass surgery, in people over age of 18; hospitalized for scheduled beating heart bypass surgery The aim question is to evaluate the ability of a less invasive cardiac output monitor (uncalibrated pulse wave contour analysis) compared with a reference cardiac output measurement (transesophageal echocardiography) to enable optimization of vascular filling by good assessment of the response to vascular filling in a high-risk perioperative patient population.

As part of hemodynamic monitoring, every patient undergoing beating-heart coronary bypass surgery is fitted with a radial arterial catheter immediately after induction of anesthesia, enabling continuous measurement of blood pressure. Hemodynamic optimization in these patients also involves fitting a transesophageal ultrasound probe to optimize cardiac output using the various therapies available (vascular filling, vasopressors, inotropes).

A specific sensor (FloTrac°, Hemosphere, Edwards°) will be connected to the arterial pressure line to obtain a systolic ejection volume value by analyzing the contour of the uncalibrated pulse wave.

The hemodynamic management of the patient, and the decision to perform a vascular filling test, will be left to the discretion of the practitioner in charge of the patient in the operating room.

Inclusion Criteria:

Patient :

• 18 years of age and older
• Hospitalized for scheduled beating-heart coronary bypass surgery
• Beneficiary of a social security plan
• Not opposed to participating

Exclusion Criteria:

• Patients undergoing surgery with extracorporeal circulation
• Patients with a history of surgery or intra-esophageal pathology contraindicating TEE
• Patient refusing to participate in the study
• Unavailability of TEE or uncalibrated pulse-wave contour device
• Minors
• Protected adults, adults unable to give consent and not under protective supervision
• Persons deprived of liberty, hospitalized without consent
• Pregnant women, parturients and nursing mothers
• Patients not affiliated to the social security system
• Emergency situations

Patient admitted to the cardiac surgery department for surgery under extracorporeal circulation