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 and to the right suggesting that at rest these hearts were operating at the peak of their function curves.
Patients in group B had a higher incidence of anterior infarction and a lower control mean arterial pressure than patients in group A, but other clinical and control hemodynamic values did not differ between the two groups. Follow-up data suggest that patients in group B may have had a higher mortality within the first 6 months following AMI.
Changing preload by PVE appears to be a safe and potentially useful means of assessing ventricular function following AMI and deserves further study.
- Ventricular function curve
- Cardiac output
- Left ventricular end-diastolic pressure
- Left ventricular peak dp/dt
- Maximal velocity of contractile element shortening
- Left ventricular stroke work
- Systolic time intervals
- Received June 23, 1972.
- Accepted December 18, 1972.
- © 1973 American Heart Association, Inc.