Radionuclide ventriculography and two dimensional echocardiography as predictors of left ventricular performance...

Sixteen consecutive patients scheduled for elective aortic vascular surgery underwent preoperative LVEF determination employing two dimensional echocardiography (2DE) and radionuclide ventriculography (RNV). Measured and derived indices of cardiac function were recorded before and after induction of anaesthesia, aortic cross-clamping and aortic unclamping. Induction of anaesthesia was associated with significant decreases in mean arterial pressure (MAP), pulmonary capillary wedge pressure (PCWP), cardiac index (CI) and with a highly significant decrease in left ventricular stroke work index (LVSWI). Aortic cross-clamping was associated with significant increases in MAP and systemic vascular resistance (SVR) whereas aortic unclamping was associated with a significant decrease in SVR. Preoperative LVEF, as measured by RNV and 2DE, were similar. Resting ejection fractions correlated poorly with both preoperative cardiac indices and with changes in indices of left ventricular performance seen intraoperatively. Preoperative ejection fraction determination did not predict intraoperative left ventricular performance. Preoperative exercise scanning may prove more informative.