Evaluation of Hemodynamic Changes of the Left Ventricle Following the Use of Extracorporeal Circulation
Condition: Coronary Surgery
Study type: Interventional

Summary: 
      The interpretation of perioperative measures of cardiac function during cardiac surgery is
      complicated. In particular, the evaluation of the diastolic compliance of the left ventricle.
      In addition, they are subject to variations induced by post-charge changes caused by the
      anesthesia, extracorporeal circulation (ECC) and the surgical procedure itself.

      Left ventricular failure is frequently measured by alteration of LV contractile properties,
      and very rarely by alteration of LV compliance. However, both contractility (systolic) and
      relaxation (diastolic) parameters are important for the left ventricle to perform its
      function adequately. Left ventricular failure after cardiac surgery with extracorporeal
      circulation and cardiac arrest under cardioplegia protection is an important and frequently
      reported complication. The investigator's objectives are to characterize the diastolic
      hemodynamic mechanisms of this left ventricular failure and to identify predictors of this
      failure in the postoperative period.

      The quantification of the systolic and diastolic functions of the left ventricle by
      ventricular pressure-volume curves is the technique of reference today, because it allows to
      determine parameters that are independent of the pre- and post-load conditions. Previous
      studies using the conductance catheter for the purpose of estimating left ventricular
      function perioperatively are rare and report conflicting results. In addition, they were
      mainly intended to measure the systolic function of the left ventricle. Only one reported the
      diastolic relaxation parameters evaluated by a conductance catheter. This study showed
      immediately after withdrawal of the extracorporeal circulation a significant alteration of
      the diastolic relaxation of the left ventricle, but was not interested in its early (kinetic)
      evolution peroperatively.

      The investigator's experience shows that, in the quarter-hour following the weaning of the
      extracorporeal circulation, a decrease in filling pressures of the left ventricle concomitant
      with an increase in cardiac output is objectified. These observations are consistent with a
      significant improvement in left ventricle compliance, but have never been reported.

      The objectives of this study are:

        -  To characterize the left ventricular diastolic failure after withdrawal of the
           extracorporeal circulation in coronary surgery.

        -  To identify the kinetics of this early diastolic failure after withdrawal of the
           extracorporeal circulation.
    


Intervention name(s): Pressure/Volume Combination Catheter; Transthoracic echocardiography; Transesophageal echocardiogram
Intervention type(s): Device; Device; Device
Intervention description(s): Hemodynamic data routinely collected and data collected by means of the placement of a Pressure/Volume Combination Catheter (Pressure/Volume Combination Catheter,Leycom,The Netherlands) will be collected simultaneously. The catheter will be placed and held in place as long as the patient is in a position to be assisted by extracorporeal circulation. This means that the placement of the catheter will follow the heparinization of the patient and the placement of the cannulas necessary for the realization of extracorporal circulation. It will be removed from the left ventricular cavity before removal of extra-corporal cannulas.; A complete transthoracic echocardiography will be performed the day before the surgical procedure, as per standard of care. It will establish the presence of the inclusion and exclusion criteria and evaluate the contractile function of the left ventricle. This will be done using a Philips IE33 echocardiograph (Koninklijke Philips Electronics N.V., Netherlands).; A transesophageal echocardiogram will be performed during the cardiac surgery, as per standard of care, using an Acuson Sequoia system (Siemens AG, Germany). It will facilitate the placement of the pressure/volume combination catheter and collect echographic data.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Prevention