Study of Myocardial Contractility After Cardiac Surgery Under an Anterograde or Retrograde Cardioplegia

Myocardial protection is a fundamental element for the safety of patients when performing cardiac surgery. For this purpose, cardioplegia were rapidly established in clinical practice to protect the myocardium when performing aortic clamp.

Cardioplegia are procedures to stop the contraction of myocardium. It is usually achieved with the use of chemicals ( cardioplegic solutions) or cold temperature (such as chilled perfusate). The composition of the cardioplegic solutions and their method of administration continuously changed over the years.

At the present date, cold blood cardioplegias are performed in the investigator's center. The investigators regularly use two modes of administration: either by an antegrade path (injection in the coronary arteries), or a retrograde one (injection in the venous system). At present, there are no elements supporting the superiority or inferiority of one path compared to another. The difficulty lies within a clear estimation of the contractility state of the ventricular cardiac muscle.

Technological developments in recent years provided a solution to this problem. The analysis of the pressure/volume curves generated by a ventricle allows an accurate quantification of the myocardial contractility. This requires the use of conductance catheters to accurately measure the ventricular volume and the ventricular pressure. The absolute ventricular contractility is then deduced with the help of a software.

The investigators intend to use this pressure-volume loops, obtained with conductance catheters, to compare the contractility of the right heart ventricle after antegrade vs retrograde cardioplegia.