Using hemodynamic monitoring by flow-directed heart catheterization in acute myocardial infarction, left ventricular dysfunction can be analyzed and quantified. Differential therapy concerning substitution of volume and administration of drugs with influence on pre- and after-load is facilitated. Since the introduction of the Swan-Ganz flow-directed catheter the monitoring has been technically improved with the additional advantage of lower incidence of catheter-induced arrhythmias and the possibility to measure the pulmonary capillary wedge pressure. The Swan-Ganz thermodilution catheter further improved the technical assessment of cardiac output. Using hemodynamic monitoring during acute myocardial infarction different phases of cardiac failure can be discerned, e.g., backward failure with increased filling pressure, foreward failure with decreased cardiac output, and cardiogenic shock with the combination of both. In some cases a hyperkinetic hemodynamic status is observed. The differential diagnosis of pulmonary embolism, and cardiac and pulmonary shock can be clarified. Complications of myocardial infarction as acute mitral insufficiency due to papillary muscle rupture in inferior myocardial infarction, rupture of the septal myocardium in septal infarction, as well as myocardial rupture with pericardial tamponade show characteristic diagnostic findings. Drug therapy with influence on pre- and after-load and therapy with positive-inotropic agents can be adjusted to the individual hemodynamic status and to the monitored drug effects.(ABSTRACT TRUNCATED AT 250 WORDS)