Evaluation of Cardiac Function in Acute Coronary Disease by Integration of Computerized Cardiovascular Signals

Abstract

The principle of invasive monitoring measurements is established for critically ill patients. However, less critical patients who are at risk can obviously benefit as much of the logic of this invasive approach, that is, to take with greater confidence and more rapidly decisions concerning prognosis and therapy based on quantitative measurements of significant variables of the cardiovascular system. Patients with acute myocardial infarction are those, but also some risk patients for needed surgical procedures and even septic patients with cardio-pulmonary complications. The monitoring procedure generally includes the measurements of right atrial, pulmonary and pulmonary wedge pressures with the Swan Ganz catheter, and intra arterial pressure with an indwelling radial catheter. Cardiac output is measured by thermodilution or Fick technique. The decision of invasive monitoring is quite evidently dependent upon risk/benefit ratio. Potential adverse effects must be reduced to a minimum and the benefit is that the therapy must be possibly modified immediately and favourably by the procedure. Our experience with haemodynamic monitoring started in 1972. As we extended the procedure to many of our patients in the coronary care unit, we soon faced multiple problems related to the safety of prolonged monitoring, education and skill of physicians and nurses, accuracy of the measurements and of the calculations, repetition of the procedures for the evaluation of the therapy initiated and charting these results in correlation with clinical data. Since 1974, each of these points has always been considered in the successive developments of a computer system aimed to improve the application of invasive haemodynamic monitoring in improving the risk/benefit ratio of the procedures.