[Hemodynamic aspect of post ECC cardiac failures. Study of 193 cases]

The aim of this study is to define the hemodynamic characteristics of this "clinical model" of acute cardiac failure observed after cardiac surgery carried out under extra-corporeal circulation, which constitutes the essential cause of "post-operative low cardiac output syndrome". The 193 patients in this study make up a representative sample of patients operated, treated and studied according to a homogeneous methodology for a period of 1 year. The clinical analysis of the post-operative circulatory condition, after exclusion of non cardiogenic syndromes, led to grouping the cases into 5 classes of circulatory change of increasing severity, each corresponding to a specific "therapeutic necessity". The hemodynamic results (intra-vascular pressures, oxymetry, cardiac output by "Cardio-Green" dilution method) are given for each of the five classes, thus defining the "hemodynamic profile" and the statistical reliability of the main objective parameters. This gives proof of the therapeutic indications for the main therapeutic procedures actually known, for which we prevent the hemodynamic effects noted for each of them. Thus, three "degrees of cardiac failure" are found: less severe (classes I and II) call for simple metabolic equilibration and possibly diuretics: the systolic work is above 160 gm/m2. Decompensated circulatory failure (classes III and IV) corresponds to a more important reduction in systolic work (9) 15 gm/m2, i.e. between 20 et 40 p. 100 of the basal value), and call for sympatho-mimetic cardiotonic agents: isoprenaline and/or dopamine. Below this value, in spite of medical treatment, the hemodynamic situation can still be sometimes reversible under circulatory assistance (diastolic counter pressure by means of an aortic balloon). Confronted with the clinical picture, the hemodynamic study enables the quantification of the circulatory change, and specification of the cardiogenic part and thus especially helps the carrying out of the treatment.