Assessment of ventricular function after acute myocardial infarction by plasma volume expansion.

In order to see if changes in preload could be used to help assess left ventricular function, 24 patients with uncomplicated acute myocardial infarction (AMI) received plasma volume expansion (PVE). In eight patients (group A) cardiac index (CI) increased by 20% or more, and in 16 patients (group B) CI increased by less than 20% or decreased. By plotting left ventricular stroke-work index (LVSWI) against left ventricular end-diastolic pressure (LVEDP) before and after PVE, the ventricular function curves upon which the heart was operating could be assessed. In group A patients the values moved upward and to the right, while in group B the values during PVE moved horizontally or downward anid to the right suggesting that at rest these hearts